Description of engine

(Click on any engine photo to view a larger version.)

02—Edwards 5-Cylinder Radial, designed and built by Forest Edwards, early 1980's, L=12", W=2", H=13"

Forest Edwards builds and flies scale model airplanes and engineers miniature engines.  He has won numerous awards for his scale airplanes, engines and flying skills. In the early 1980s, Edwards designed and developed this 5-cylinder radial engine to power his 1/4-scale Fleet model airplane, based on the 1930 Fleet Biplane. He received many requests to manufacture the engine, so between 1982 and 1994, Edwards produced 30 engines. Many were installed into model airplanes and some are still being flown today.

The 5-cylinder radial burns regular gasoline, incorporates a dry sump lubrication system and produces more than six horsepower. In his last few engines, Edwards added a centrifugal advance in the distributor and a crankshaft-driven supercharger for maximum performance.  Edwards’ engines are completely machined from 7075 aircraft-grade aluminum and are perhaps the most reliable model radial engines built to date.

To see a video of how a radial engine works CLICK HERE. The link is to a YouTube.com video generated in a 3D drawing program called Autodesk Inventor. The cutaway view shows the pistons in action on a 7-cylinder radial engine so you can see how all the internal movements are related.

03—Bentley BR2 Rotary Aero Engine, 1/4 scale model built by Paul Knapp, Arizona, 1993. The model weighs almost 12.5 pounds without stand. L=14", W=12.5", H=14"

Paul Knapp constructed this model with the help of Lew Blackmore's book, Bently BR2 and computer aided design (CAD) drawings by Bill Mazak of Arizona. The engine is machined from stainless steel with aluminum cylinders and heads. The engine burns regular gasoline on spark ignition, has a pressurized lubrication system and a carburetor like its full-size counterpart.

The rotary engines of World War I rotated with the propeller. The hollow crankshaft that extended from the back of the engine was fixed to the airframe and the crankcase was attached to the propeller. Thus, the crankcase and cylinders rotate with the propeller about the stationary crankshaft. The Bentley BR2 was produced in England and was the largest and most powerful rotary engine used in WWI. It powered many airplanes, most of them biplanes.

Paul built four of these engines—two in stainless steel like this one and two of aluminum.. To see a video of one of the aluminum versions power a model airplane called the Gigantic by Robert Cooper with an 12-foot wingspan on its maiden flight, see http://www.youtube.com/watch?v=dSYp1jFz6_E. This flight purportedly broke two world records on December 4, 2009—the first flight by a 1/4 scale rotary engine and the first flight by a model of a Bentley BR2. Photos show the engine mounted to the firewall, the Gigantic about to land after its first flight and the people involved: (L to R) Mac Hodges (pilot), Ray Williams, Dale Cavin, Robert Cooper and Paul Knapp.

07—Conley Small-Block V8 Engine, designed (1988) by Gary Conley, Illinois, model built by Paul Knapp, Arizona, 1993. L=15", W=7", H=10"

This methanol-burning small-block V8 was built from a casting kit designed by Gary Conley.  It incorporates a fully functional scale 671 blower with dual carburetors.  It will turn approximately 12,000 revolutions per minute at full throttle.

(See YouTube.com at http://www.youtube.com/watch?v=4Is9hcU78gA&feature=PlayList&p=865DCA5FEDB69FB5&index=35 for video of a non-supercharged Conley V8 being run, or see Gary Conley's web site at www.conleyprecision.com.)

10—Cirrus 4-Cylinder Inline Aero Engine, 1/4 scale model built by Merritt Zimmerman, circa 1989, L=19", W=8", H=10"

The 1/4 scale Cirrus 4-cylinder model is one of six made by Merritt Zimmerman. It operates on gasoline with oil mixed in for lubrication. Zimmerman also made 75 1/6-scale-model Cirrus 4-cylinder engines. (One 1/6-scale model also is on display.)

Zimmerman began building miniature engines in the 1940s.  He designed and produced his own castings and also did his own machining. At 83, in less than six weeks, Zimmerman designed, built and tested a 1/4-scale model of the 5-cylinder Kinner radial engine. His engine and drawings were published in 1993 in construction articles in Strictly IC magazine (www.strictlyic.com).

The in-line engine has cylinders in a straight row, or in two rows side-by-side.  The full-size Cirrus 4-cylinder was commonly used in the Avro Baby (designed in 1918) and the de Havilland D.H. 60 Moth (1930-1936).

14—Seidel ST540 5-Cylinder Radial Model Aircraft Engine, designed and built by Wolfgang Seidel, Germany, 1992. L=9", W=8", H=9"

Wolfgang Seidel designed and built several custom radial engines. The ST540, ST770 and ST996 were among the smaller series of radial engines that were used in one-fifth scale and one-fourth scale model aircraft. These engines varied in size from about 8 inches to 11 inches in diameter.

The ST540 is the smaller 5-cylinder 40cc (2.43 cubic inch) radial engine with a speed range of 1,100 to 6,800 revolutions per minute, using a 22-6 propeller. It burns methanol with castor oil mixed in for lubrication, and it is capable of producing 2.8 horsepower.

15—Seidel ST 770 7-Cylinder Radial Model Aircraft Engine, designed and built by Wolfgang Seidel, Germany, 1992, L=10", W=10", H=12"

Wolfgang Seidel designed and built several custom radial engines. The ST540, ST770 and ST996 were among the smaller series of radial engines that were used in one-fifth-scale and one-fourth-scale model aircraft. These engines varied in size from approximately 8 inches to 11 inches in diameter.

The ST770 is a 7-cylinder 70cc (4.17 cubic inch) radial engine with a speed range or 1,000 to 6, 000 revolutions per minute (rpm), using a 26-10 propeller. Its maximum speed is 6300 rpm. It burns methanol with castor oil mixed in for lubrication, and is capable of producing 4.0 horsepower.

16—Seidel ST 996 9-Cylinder Radial Model Aircraft Engine, designed and built by Wolfgang Seidel, Germany, 1993. L=9", W=11", H=13"

Wolfgang Seidel designed and built several custom radial engines.  The ST540, ST770 and ST996 were among the smaller series of radial engines that were used in one-fifth-scale and one-fourth-scale model aircraft. These engines varied in size from approximately 8 inches to 11 inches in diameter.

The ST996 9-cylinder 96cc (5.9 cubic inches) is the largest of the three in this series of engines. It has a speed range of 1,000 to 5,000 revolutions per minute using a 26-10 propeller. It burns methanol with castor oil mixed in for lubrication, and it is capable of producing 5.4 horsepower.

20—Morton M5 Radial Model Aircraft Engine (cutaway), built by Dennis Fadden, Canada, 1990s. L=7", W=6", H=7"

Bruce Satra, of Utah reproduced a Morton M5 engine from 1940s plans and made aluminum castings from the model. Dennis Fadden used Satra’s castings to build this cutaway. Fadden’s M5 has a master-rod that is in the top cylinder with the remaining articulating rods attached to the master. This is a perfect example of how a typical 5-cylinder radial engine operates.

The Morton M5 was originally manufactured in the 1940s and was the first miniature radial engine made for model airplanes. It was designed by Glen Morton of Morton Aviation and was based on the full-size LeBlond radial aircraft engine made in 1928. The radial engine was much more powerful and reliable than the old rotary design. It was used to power large aircraft such as airliners and World War II-era bombers.

34—Cirrus 4-Cylinder In-Line Aero Engine, 1/6-scale model built by Merritt Zimmerman, 1980-1994. L=7", W=3", H=5" 

Merritt Zimmerman produced his own castings to build 75 of this 1/6-scale Cirrus engine (glow ignition) from about 1980 to 1994. He sold many more castings in kit form for miniature engine builders during the same period. To differentiate his engines from those built by others, an oval-shaped embossed emblem with the name Z H Cirrus was bonded to the crankcase identifying those engines completed by him. The oval emblem was not sold or included in any of the kits.

This engine differs from Zimmerman’s prototype in that the cylinders are independent of each other as in the full-size engine. The head is one piece but machined to give the appearance of individual heads characteristic of the full-size engine.  The cam was relocated to the correct side of the engine and the induction system changed to provide lubrication to the internal parts before entering the combustion chamber, typical for a glow-ignition engine.

40—Miniature SJ7 Pulsejet Engine, built by Mike Early, Arizona, circa 1996. L=29", W=13", H=10"

Perhaps the most famous pulsejet engine is the Argus V1 “Buzz Bomb” made by Germans in World War II. Fuel was sprayed directly into the engine through a 3 x 3 array of nine nozzles behind a valve grid—a direct-injection pulsejet. The fuel supply was pressurized by the tank of compressed air that was also used to drive the gyros and operate the control surfaces of the V1 airframe.

This miniature pulsejet engine operates exactly like the V1. It burns regular gasoline and has a variable thrust range from 1/2 to 6 1/2 pounds. Mike Early developed and built the engine, and made the aluminum castings for the intake. He fabricated the combustion chamber and tailpipe from stainless-steel sheet metal. Early produced approximately 12 models from 1996 to 1998.

Anyone who has ever heard a pulsejet run will not forget the sound. It is LOUD, as it is essentially one long controlled explosion.

43—de Havilland Gipsy I 4-Cylinder Inline Engine, 1/4-scale model built by Pat Loop, 1990s. L=8", W=4", H=8", Weight = 9 lb, 2 oz.

Pat Loop handcrafted this miniature Gipsy right down to the spark plugs. It runs on gasoline with spark ignition and a pressurized wet sump lubrication system. Les Chenery provided the castings.

Inline engines have cylinders in a straight row, or in two rows side-by-side. The Gipsy I upright, air-cooled engine was commonly used in the de Havilland 60G and 60M Gipsy Moth and the de Havilland 60T Gipsy Moth trainer. The first de Havilland 60 Moth was built in 1925 as a sports aircraft and a trainer. In 1928, a Gipsy engine was “sealed” and flown for 600 hours.

44—Kinner 5-Cylinder Airplane Engine, 1/4-scale model designed and built by Merritt Zimmerman, Michigan, 1994. L=9", W=11", H=12"

The Kinner Airplane & Motor Corp. of California began building 5-cylinder engines in 1919. The company also built light aircraft from 1931 to 1937. In 1939, the company changed its name to Kinner Motors and produced engines for thousands of World War II training aircraft.

At the age of 83, Merritt Zimmerman designed, drafted, fabricated and tested this scale model within six weeks.

47—Berger 7-Cylinder Radial Model Airplane Engine, designed and built by Lee Berger, California, circa 2001. L=8", W=8", H=9"

This is the first successful 2-cycle radial engine using a common crankshaft with a master rod and articulating rods inside a common crankcase. Since every cylinder of a 2-cycle engine fires on every revolution, an even or odd number of cylinders can be used. In 4-cycle engines, however, each cylinder fires every other revolution, thus requiring an odd number of cylinders.

Two-cycle engines require pressure inside the crankcase to force fuel into the combustion chamber on the intake cycle. In order to accomplish this, Lee Berger designed a positive-pressure pump (supercharger) in the back of the crankcase that maintains constant pressure in the crankcase during operation. A supercharger increases the atmospheric pressure to create more horsepower.

48—Conley V8 Engine, designed and built by Gary Conley, Illinois, 1985. L=8", W=6", H=6"

Gary Conley built several machined V8 engines. He also built a few V4, V6 and V12 models. In 1988-89, he fabricated the molds and patterns to produce a casting kit for his V8 and made it available in several variations. Most commonly, it was supplied with a carburetor, but later versions included multiple carburetors with velocity stacks (specially configured tubes that increase the velocity and direct the air into the carburetor).  Other variations came with miniature superchargers, such as the Roots-style 671 blower commonly seen on hotrods and dragsters in the 1960s.

(See Gary Conley's site at www.conleyprecision.com.)

(See also YouTube.com at http://www.youtube.com/watch?v=4Is9hcU78gA&feature=PlayList&p=865DCA5FEDB69FB5&index=35 for video of a Conley V8 (not this one) being run.)

55—Seidel ST 726 7-Cylinder Radial Model Aircraft Engine, designed and built by Wolfgang Seidel, Germany, 2000. L=10", W=14", H=16"

Wolfgang Seidel designed and produced many small 5-, 7- and 9-cylinder radial engines for model airplanes in the early 1990s. In the late 1990s, his designs led to larger engines, including 5-, 7- and 14-cylinder two-row radials.

The ST 726 is a 7-cylinder 260cc (15.6 cubic inch) radial that weighs approximately 16 pounds.  It burns methanol with castor oil mixed in for lubrication. It swings a 32-12 propeller at 4,500 revolutions per minute.

56—Seidel ST 1426 14-Cylinder Radial Model Aircraft Engine, designed and built by Wolfgang Seidel, Germany, 2000. L=14", W=14", H=16", 31 lb 8 oz with display stand

Wolfgang Seidel custom designed and built several radial engines. The ST540, ST770 and ST996 were among the smaller series of radial engines that were used in one-fifth scale and one-fourth scale model aircraft. In the late 1990s, Seidel designed a larger series of radial engines that are commonly used in the larger one-quarter scale or smaller one-third scale model aircraft.

The ST1426 is the largest engine in the series, and perhaps the largest model airplane engine commercially sold. It is a 14-cylinder two-row 520cc (31.2 cubic inch) radial that is 14 inches in diameter, weighing 28 pounds and turning approximately 4,000 revolutions per minute.

To view a video of a Seidel ST 1426 being run CLICK HERE.

57—“Kitty Hawk” 4-Cylinder Inline Engine, 1/4-scale model made by Lloyd Butler, Ohio, 1980s. L=9", W=10", H=6"

The engine used in the 1903 Wright brothers’ flyer was a 4-cylinder, 4-cycle, internal-combustion engine that lifted the world’s first airplane and its pilot into the air in 1903. The engine was designed and built by Charlie Taylor and the Wright brothers. The engine had no fuel pump, carburetor or spark plugs. It was water cooled and generated 12 horsepower.

Lloyd Butler’s miniature “first engine of flight” model is liquid cooled and burns gasoline on a make-and-break ignition system—just like the full-size engine. A spark is generated between electrodes by breaking contact between them, a system specially adapted for internal combustion engines.

60—Micro Cirrus 4-Cylinder Inline Engine, designed by Merritt Zimmerman, 19741/12-scale models, built in Ukraine, 2001 and 2003. L=5", W=6", H=4"

Two variations of the model Cirrus engine are these micro engines from Ukraine. (See also #112 below for the V-8 version.) They run on methanol with glow ignition and are among the smallest multi-cylinder 4-cycle engines in the world. The custom glow plugs are only a 5mm hex with a 3.5mm thread. The engines are less than 4 inches long and have a mere .5cc displacement in each cylinder, making the 4-cylinder only 2cc and the V8 only 4cc total displacement. Initial test results proved these micro engines would spin their 7- and 8-inch propellers to 13,000 revolutions per minute.

Only 25 of the 1/12-scale 4-cylinder air-cooled engines were produced in 2001 and another 25 of a water-cooled version. In 2003, the remaining parts for the 4-cylinder engines were used to manufacture less than a half dozen each of the air-cooled and water-cooled V8 engines.

62—"Triscamp" 3-Cylinder Miniature Radial Engine, designed and built by Robert Washburn, Washington, circa 1990

Robert Washburn designed and fabricated eight of these tiny 3-cylinder, 2-cycle, methanol-burning radial engines by gearing together three individual engines into one housing.  Lubrication is provided by castor oil mixed with the fuel.

Frances and Robert Washburn published Strictly IC magazine from 1987 until 2001. At the time it was the only publication devoted to the design, development, machining and construction of miniature internal combustion engines. All back issues are still available at www.strictlyic.com.

66—Wall "Wizard" 2-Cylinder Opposed Engine, designed and manufactured by Elmer A. Wall, Wall's Model Engine Laboratory, Chicahg, Illinois, 1940's. L=8", W=12", H=7"

Elmer A. Wall began designing and manufacturing casting kits for miniature internal combustion engines during the Great Depression (1929-1941) and continued until his death in 1948. Among his designs was this 45 cc air cooled 4-cycle engine with overhead valves. He advertised that the engine was so well balanced that it would "start on the first turn-over if machined properly and that it would idle down to a tick or roar full speed when the throttle is opened."

67—Zimmerman “Cirrus” 4-Cycle V8 Engine, 1/6-scale model built by Profi M.E., 2001. L=14", W=6", H=6"

Modifications to the original Zimmerman design are the addition of 4 cylinders and a geared flywheel instead of a propeller hub, making it suitable for a small automobile or power boat. The gear on the flywheel drives a water pump for circulating coolant around the cylinders, through the heads, and into the radiator. Each of the two carburetors fuels one bank of four cylinders.

The connecting rod journals on the crankshaft are located opposite each other at 180 degrees, while the pistons and cylinders are mounted 90 degrees apart. The internal parts are lubricated with a small amount of oil in the crankcase, and with oil mixed in the fuel. The external rockers require manual oiling before running the engine.

70—Seidel ST525 5-Cylinder Radial Model Airplane Engine, designed and built by Wolfgang Seidel, Germany, 2000. L=14", W=12", H=12", Weight=14 lb 12 oz with display stand

This is among the largest 5-cylinder model-airplane engines built to date. It measures approximately 12 inches in diameter and 10 inches in length. It weighs approximately 12 pounds with 8 cubic inches (128cc) total displacement.  It runs on methanol with spark ignition. This is one of a few that has Wolfgang Seidel’s custom electronic ignition on the back of the engine.

75—Eldon I 2636 6-Cylinder Model Boat Engine, designed and built by Eldon Dwyer, New Mexico, early 1980s. L=14", W=8", H=7"

After building a prototype from bar stock, Dwyer made the patterns and castings to produce a second engine that he used in his power boat in 1982. It was modified for an electric starter since it was not readily accessible once mounted in the boat.

In the early 1980s, Dwyer started a company called Robotronics that produced and sold a casting kit and drawings for the engine. It is not known how many kits he manufactured and sold. In the early 1990s, Paul Knapp's Miniature Engineering Museum acquired his patterns, prototype, and this engine.

76—Gay 4-Cylinder Engine, designed and built in, San Diego, California, 1927. L=10", W=7", H=8", Weight=12 lb 4 0z

An instructor (Mr. Gay) and his class at the Naval Machinist School produced this 4-cycle air-cooled overhead-valve engine from aluminum castings, bronze and iron. The crankcase is cast in bronze, making the engine somewhat heavy, but eliminating the need to fabricate and insert crankshaft bearings. The crankcase is the oil reservoir for lubricating the internal parts. The crankshaft slings the oil as it spins. The external overhead rocker assembly is manually lubricated before running the engine.

The spark plugs were originally located on the side of the cylinder block, common for lower-compression engines. Perhaps to improve starting the engine or to improve its performance the plugs were relocated to the top of the head. An aluminum extension (slug) was bolted to the top of each piston to increase compression. The original spark-plug holes were then filled with brass plugs.

84—"Little Dominator" Model Aircraft Engine, designed and built by Noel Jensen, Montana, circa 1993. L=8", W=8", H=9"

When Noel Jensen needed an engine for his model airplane he drew a couple sketches, went into his workshop and produced a rotary valve, twin cylinder, air cooled engine that he called the Little Dominator. His engineering and machining skills led him to a simple design and efficient powerplant. The engine’s one-inch bore and 1.1-inch stroke turns a 16/6 propeller at 6000 revolutions per minute. The engine burns methanol on glow ignition and utilizes belt driven rotary (cylindrical) valves for induction and exhaust.

85—"Dominator" Model Aircraft Engine, designed and built by Noel Jensen, Montana, circa 1993. L=8", W=8", H=9"

See the "Little Dominator" engine above for Noel Jensen's basic design specifications. To achieve more power, Jensen added two more cylinders and produced the flat 4-cylinder opposed model he dubbed the Dominator. It sports ringed pistons, bronze-bushed rods, ball bearing crankshaft and stainless steel cylindrical rotors for valves. Its one-inch bore and stroke will spin a 20/8 propeller at 6000 revolutions per minute.

91—Clarke 1-Cylinder Trolling Boat Motor, 1/3-scale model built by Profi M. E., Ukraine, 2000. L=5", W=3", H=8"

The full-size motor was originally manufactured in Michigan in the 1930s. The propeller is mounted directly to the crankshaft and the entire engine is submerged under water for cooling.  It was only 21 inches long, so it was convenient to transport and to mount to the back of a boat. The operator would tilt the motor out of the water, wind a rope around the pulley and then quickly pull the rope to start the motor (like starting a lawnmower). The curved splash guard above the propeller protected the operator from becoming soaked while tipping the running motor back into the water. The aluminum tube carried the exhaust from the motor up and out of the water to prevent water from entering the motor when it was turned off.

This model is a copy of the full-size 1– horsepower motor.

92—Clarke 2-Cylinder Trolling Boat Motor, 1/3-scale model built by Profi M. E., Ukraine, 2002. L=6", W=3", H=10"

Like the model above, the full-size version of this motor was originally manufactured in Michigan in the 1930s. It operates in the same manner, with the entire motor operating underwater to keep it cool while air is ducted down through the cast case. The copper exhaust pipe runs up above water level and then back down to exhaust under water. This keeps water from entering the motor through the exhaust pipe when the motor is not running.

This model is a copy of the full-size 2-horsepower motor.

93—Luhrs Mini Single-Cylinder, 4-Cycle Engine, built by George Luhrs, Long Island, NY, circa 2001. L=6", W=3", H=6"

Two limiting factors in the miniaturization of gasoline engines are the size of the air and fuel molecules. George Luhrs dispelled the theory that gasoline burning, spark ignition engines can be miniaturized only so far, considering this engines is one of the largest he has built. With a bore and stroke of only 1/8 of an inch, one of his smaller four-cycle, single-cylinder gasoline engines nearly fits inside the gas tank of this engine, and his tiny works of art run magnificently.

George is a master at micro engineering, machining and finishing and has produced a five-cylinder, four-cycle, spark ignition radial engine that fits inside a coffee cup. He has won many awards for his efforts.

109—Stover Type “K” Stationary Engine, Freeport, Illinois, 1920s, model built by George Luhrs, NY, 1990s. L=5", W=3", H=4"

Stationary engines were extensively used to power machinery and equipment in all industries from the late 1800’s into the mid 1940’s. D.C. Stover was a prolific inventor and began manufacturing various products in 1862. In 1916 he formed the Stover Manufacturing and Engine Company and production peaked in 1919. Before closing their doors in February 1942 Stover shipped 277,558 engines. 

George Luhrs is known for producing the smallest engines in the world and his miniature Stover is no exception. He machines every part from bar stock and utilizes no castings. It burns gasoline on spark ignition and, just as its full-size counterpart, requires manual lubrication before operation. Spark is produced by a small coil and battery located in the base.

The engine is accompanied by a box to transport it. The wood for the box and base match, and the lid of the box contains a few special tools to aid in running the motor.

112—"Micro Cirrus" V8 Engine, designed by Merritt Zimmerman, 1974, 1/12-scale model manufactured by Profi ME, Ukraine, 2001 - 2003 

Two variations of the model Cirrus engine are these micro engines from Ukraine. (The 4-cylinder version can be seen as #60 above.) They run on methanol with glow ignition and are among the smallest multi-cylinder 4-cycle engines in the world. The custom glow plugs are only a 5mm hex with a 3.5mm thread. The engines are less than 4 inches long and have a mere .5cc displacement in each cylinder, making the 4-cylinder only 2cc and the V8 only 4cc total displacement. Initial test results proved these micro engines would spin their 7- and 8-inch propellers to 13,000 revolutions per minute.

Only 25 of the 1/12-scale 4-cylinder air-cooled engines were produced in 2001 and another 25 of a water-cooled version. In 2003, the remaining parts for the 4-cylinder engines were used to manufacture less than a half dozen each of the air-cooled and water-cooled V8 engines.

114—Gnome 160 Rotary Airplane Engine, 1/3 Scale model built by Ray Williams, New York, 2001. L=24", W=16", H=19", Display weight=47 lb 10 oz

Ray Williams built both a 1/3 scale model of the Gnome 160 horsepower rotary engine and the World War I Avro 504K airplane that was designed in 1913 in the United Kingdom. Williams flew his model in December, 2001 making this the first model rotary engine ever to fly.

The model engine, as in the full-size engine, operates on gasoline with spark ignition and a pressurized oil system. It has a displacement of 27 cu. in. and the engine itself weighs 11 pounds. The scale model Avro 504K into which it was fitted had a 12-foot wingspan.

The first successful air cooled rotary engine was developed in 1896 in the United States. The French-built Gnome rotary was used extensively in airplanes during World War I. A typical rotary engine has a fixed crankshaft with rotating cylinders and crankcase that carry the propeller. Since the oil cannot be reclaimed from a rotating engine, it is discharged after combustion. (This is known as a "total loss" oiling system.) WWI pilots would constantly have to wipe off their goggles and windscreens from this oil spray during flight.

115—Valentine "Blitz" 1-cylinder Diesel Engine, designed and built by Ron Valentine, Germany, circa 1993

This and the following engine are among the smallest engines in the world. (Note the U.S. quarter dollar coin used as the support base for a size reference.) These 2-cycle diesel engines burn a special diesel fuel that is less viscous and produces combustion when head and pressure are applied. The piston and cylinder are lapped, a machining process that matches the piston to the cylinder so closely in size (within millionths of an inch) that  piston rings are not needed.

A diesel engine has no spark plug. As the piston compresses the fuel and air mixture into the top of the combustion chamber, the heat caused by compression eventually causes it to explode.

116—Valentine "Rasant" 1-cylinder Diesel Engine, designed and built by Ron Valentine, Germany, circa 1993

This and the previous engine are among the smallest engines in the world. (Note the U.S. quarter dollar coin used as the support base for a size reference.) These 2-cycle diesel engines burn a special diesel fuel that is less viscous and produces combustion when head and pressure are applied. The piston and cylinder are lapped, a machining process that matches the piston to the cylinder so closely in size (within millionths of an inch) that  piston rings are not needed.

A diesel engine has no spark plug. As the piston compresses the fuel and air mixture into the top of the combustion chamber, the heat caused by compression eventually causes it to explode.

124—"Sea Lion" 4-Cylinder, 4-Cycle, Water Cooled Marine Engine, built by Jim Hawk, circa 1980's.  L=13", W=6", H=9"

This tiny marine engine was designed and sold as a casting kit by Edgar Westbury of England. Jim Hawk made several modifications to the original design to improve efficiency and performance. He increased the flow of coolant by fabricating centrifugal water pump to replace the original small gear pump. He designed a new dry sump lubrication system and improved the compression ratio by fabricating pistons with oil control rings, a stronger head and combustion chamber as well as stronger, lighter alloy connecting rods. 

126—"Maxse T-Seven" 7-cylinder Radial Model Airplane Engine, built by Maxse Tayler, B.C., Canada, circa 1996. L=31", W=31", H=21" on table stand

Closely resembling the Jacobs 7-cylinder radial engine, Maxse Tayler used the piston and cylinder assemblies from the commercially manufactured Saito 120 model airplane engines. Everything else was fabricated or machined from bar stock. It sports a full compliment of accessories including electronic ignition, shielded wiring, fuel primer pump, fuel-air mixture control, high altitude carburetor pre-heater, two oil pumps, two generators and dual magnetos. The lubrication system uses a dry sump and two-stage oil pump.

It took Maxse several months just to design and fabricate the tooling to balance the master rod assembly. After completion it was equipped with oil pressure and vacuum gages for monitoring performance during operation. It took approximately 7 years to complete.

132—"Green Dragon" Model Airplane Engine, built by John Nuovo, California, early 1990's. L=7", W=5", H=6"

John Nuovo acquired the castings from Australia and produced six engines that he dubbed "Green Dragon" after applying the crackle green finish. This is an air cooled aircraft version with a light weight cast iron lined aluminum cylinder. It burns methanol with castor oil mixed in for lubrication on spark ignition. The fuel is contained within the machined aluminum tank mounted to the back of the engine. he is well known for his precise machining skills and engine building capability to produce engines for airplanes, boats and tether cars.

In 1940, a similar engine was commercially sold as a "Silver Crown Champion" from Champion Products, Co. Los Angeles, CA. The Silver Crown was primarily a boat engine with dual carburetors mounted above the crankshaft, large swept exhaust stacks, parallel head fins and a clamp-on bypass and exhaust manifold.

133—"Green Dragon" Model Automobile Engine, built by John Nuovo, California, early 1990's. L-=7", W=5", H=6"

Like the engine shown above (#132) the two-cycle, air cooled engine was dubbed "Green Dragon" due to its green crackle paint finish. A similar engine was sold commercially in the 1940's under the name "Silver Crown" from Silver Crown Co. in Los Angeles. John Nuovo acquired the aluminum castings and machined the cylinder from steel and the head from bronze. It has two carburetors mounted above the crankshaft, large swept exhaust stacks, parallel head fins and a clamp-on bypass and exhaust manifold. It runs on spark ignition and burns methanol with castor oil mixed in for lubrication. It has a pulley on the flywheel for rope starting and an adjustable timer (with points) in front for setting the spark advance.

135—"Rasant MK III" Diesel Radial Model Airplane Engine, built by Ron Vanlentine, Germany, 2004. L=2.5", W=3", H=2"

Although radial in appearance, the engine operates like an inline engine. Instead of a master rod with its articulating rods in the same plane, the three cylinders are staggered from front to back. Thererfore, the crankshaft is linear, similar to that used in an inline engine. The journals on the crank are spaced to match the cylinders at 120 degrees apart so all of the cylinders fire at the same time. It burns a special form of diesel fuel (less viscous) that produces combustion when heat and pressure is applied. The piston and cylinder are lapped together to within a tolerance of several millionths of an inch, eliminating the need for piston rings. The fuel provides a liquid seal in the cylinder and as the piston compresses the fuel-air mixture into the combustion chamber, it is ignited by heating through compression. Diesel engines require no form of mechanical or electrical ignition but can be difficult to start on cool days.

140—Manx 250IL 2-Cylinder Inline Model Airplane Engine, designed and built by Robert Hoskins, Tennessee, 1979

Robert Hoskins, President of Aero Tech Inc. (Tennessee) developed this engine in 1979 to fly his model airplane. He wanted scale sound; something the 2-cycle engines could not produce. Striving for light weight reliability, he machined this model from aluminum bar stock and engineered 13 ball bearings into it—6 that support the crankshaft alone. Although expensive to construct, the reliability and power output were worth the effort. The engine turned 7500 revolutions per minute with a 20-6 propeller on glow ignition and flew his 35-pound airplane with ease.

Responding to requests from friends Robert began to manufacture the engines for sale. It was never mass produced, but rather individually custom machined, inspected and assembled for maximum quality and reliability. Construction time was long and deliveries were slow, which led to only a few engines actually completed and sold.

143—5-Cylinder Radial Model Airplane Engine, designed and built by Barry Robinson, England, 1998. L=7", W=10", H=10"

This is an all aluminum bar stock engine with a bore of 19 mm, stroke of 19.2 mm and a total displacement of 27.21 cc. The cylinders are lined with chrome plated brass liners and the pistons incorporate compression rings. it measures about 7" in diameter and burns methanol on glow ignition. Barry constructed three of these 5-cylinder radials as well as a few 9-cylinder radials and two-cylinder opposed engines. many of the components such as the piston and cylinder assemblies are common to all of his engines.

144—2-Cylinder Opposed Model Airplane Engine, made by Barry Robinson, England, early 1990's. L=6", W=8", H=4:

Barry Robinson machined the entire engine from bar stock. It has a bore of 19 mm and a stroke of 19.2 mm for a total displacement of 10.9 cc. The cylinders are lined with chrome plated brass liners, and the pistons incorporate compression rings. It burns methanol on glow ignition. Castor oil is mixed with the fuel for internal lubrication, but the rocker arms require manual lubrication before running the engine. Barry constructed only three of these 2-cylinder airplane engines as well as a few 5-cylinder and 9-cylinder radial engines. Several of the components in this engine were used to construct the other variations he designed.

145—JT 1800 9-Cylinder Radial Model Airplane Engine, designed and built by John v. Thompson, Kansas, early 1990's. L=14", W=28" (prop), H=14"

John Thompson employed Saito 120 model airplane engine cylinder assemblies for this radial, but from that point on it is his design. Each cylinder has its own pair of cams that operate the inlet and exhaust valves. it weighs in a t 28 pounds and has a 1.25-inch (32 mm) bore and a 1-inch (24.8 mm) stroke with a total displacement of 10.8 cu. in. (180 cc). Initial tests with a 28-14 propeller indicated it produces 18+ horsepower. John incorporated a Borg Warner 1SH`1 2-inch, 10-blade turbocharger compressor for fuel distribution and atomization located within the intake manifold in the rear of the engine. it runs on glow ignition and burns gasoline with oil mixed in for lubrication. It sports his custom designed hydraulic controlled variable pitch propeller.

146—Thompson "Tarantula" 9-Engine Radial Model Aircraft Engine, designed and built by John V. Thompson, Kansas, 1970's. L=12", W=18", H=11"

Construction articles fro John's Tarantula were published in Strictly IC magazine in the 1980's. The "9-engine" part of the name is not a typo. It is because the engine consists of nine individual Cox .049 1-cylinder model airplane engines geared together in an aluminum crankcase hidden within a plastic Williams Brother Pratt & Whitney R-985 model engine kit. The nine engines are geared to the propeller shaft and all cylinders fire at the same time. It's a 9-engine engine.

The engine performed flawlessly and, surprisingly, the heat did not distort the plastic kit during operation. A single carburetor is mounted on a centralized intake manifold in the back, which has nine tubes extending from the manifold to each engine resembling the legs of a spider...thus the name, "Tarantula." The second photo shows this manifold on the back side of the engine.

147—Thompson Designs Flat Four Model Airplane Engine, model by John V. Thompson, Kansas, 1990's. L=13", W=13", H=11"

John used the cylinder assemblies from Honda weed-eater engines to produce this flat four aero engine. His custom crankcase holds the oil for lubrication and the engine runs gasoline with spark ignition. Spark is provided by a remote electronic capacitor discharge ignition with a spark advance linked to the carburetor linkage. Instead of making an intake manifold to operate all four cylinders from one carburetor, John chose to leave each cylinder assembly as it came from the factory with the carburetor attached to the head. Then he designed a geared linkage to connect and operate the four carburetors from one throttle cable. it swings a 24-10 propeller but no recorded specifications were found to verify its capacity or performance.

148—John Deere Type "E" 1-1/2 HP Stationary Engine, Gene Dettmar prototype, Dettmar Industries, Waterloo, IA, 1980's. L=16", W=10", H=12"

Dettmar Industries of Waterloo, IA began to produce this 1/2 scale model of the John Deere Type "E" stationary engine in the 1980's. Little is known about the company's outcome, but few if any became available for purchase. Since the late 80's, only a small number of casting kits and completed engines have appeared.

This example is a gasoline burning stationary (hit-n-miss) engine with a 1.8-inch bore and 2-inch stroke, enclosed crankcase and a make-and-break ignition system. Oil is held in the crankcase and splashed (slung) around by the crankshaft to lubricate the internal parts while the external components require manual oiling periodically. The model swings the two massive flywheels at an average speed of 600 RPM. The flywheels store the energy necessary to power other machinery and equipment. The full-size engine used a magneto to provide the spark for ignition; however, the model uses a small battery and coil or electronic ignition to spark the contact points within the combustion chamber.

158—Morton M-42 4-cylinder, In-line, Flathead Model Car Engine, made by Jim Hawk, Oklahoma, circa 2006. L=9", W=5", H=5"

In 1944, many of the components used in the Morton M5 radial engine and M-4 inline were to be incorporated into this newly proposed M-42 flathead engine. The drawings for the M-42 were completed, but the engine never made it to production. From only one drawing that survived the Morton Company, Jim Hawk fabricated the wooden patterns, produced his own aluminum castings and machined the components to complete this running model. It burns gasoline on spark ignition and will turn a 14-6 propeller in excess of 6500 RPM.

Flathead engine were commonly called side-valve engines because the valves are  positioned in the block alongside the cylinders. Overhead valves are positioned in the head above the combustion chamber. since overhead valves ere not developed until the 1950's, the heads for the side-valve engines were flat, resulting in the name "flathead."

164—Heinen Motore (HEMO) V-4, designed and built by Jurgen Heinen, Germany, 1994. L=12", W=6", H=7"

Jurgen Heinen machined the engine from aluminum bar stock and produced the finish by hand. it has a bore of 32 mm and a stroke of 28 mm with a total displacement of 20 cc. It is a belt driven dual overhead cam single-cylinder with 4 valves—two for the intake and two for the exhaust. It burns methanol on glow ignition and spins a 20 x 8 propeller up to 14,000 RPM.

166—Sopwith Snipe Instrument Panel, 1/4-museum-scale model built by Robert Cooper, Georgia, 2003. L=6", W=9", H=8"

Robert Cooper built a “museum-scale” model of the 1918 British Sopwith Snipe fighter aircraft.  A museum-scale model contains everything as close to the real thing as possible. For example:  Most aircraft are riveted together with thousands of rivets. In a scale model the builder makes fake rivets with glue drops for each rivet. For museum scale, the model builder makes the rivets, installs them and sets them just like the full-size airplane.

Cooper’s model airplanes have several functional features including the Bentley BR2 rotary engine built by Paul Knapp with throttle quadrant, tamper valve, fuel pump and fuel filter.

This is a copy of the instrument panel from Cooper’s model. It features operating lights from individual toggle switches located in the accumulator box (lower right). The magneto switches (lower left) are below the pulsator (glass tube oil pressure gage). The turn-and-bank indicator and fuel gage are lower center. The second photo shot in low light shows the lights shining on each instrument, powered by a set of batteries on the back of the panel. The tiny switches in the lower right corner of the panel actually activate each light individually.

The pulsator and fuel gage have operational petcocks for emergency shut-off in case of glass breakage. On top are a tachometer, air speed indicator, clock and altimeter. Directly below the air speed indicator is a famous air compass type 5/17 that actually tracks true north just like its full-size counterpart.

171—Tadpole, 1/3-Scale Model of the 1939 Dooling Brother’s “Frog” Tether Car, designed and built by Ted Maciag, Florida, 2006. L=8", W=4", H=2"

Before the advent of radio control, miniature automobile races were accomplished by suspending the model car with a cable (tether) from the center of a 100-foot circular track. The speed of the car could be accurately calculated since the time to complete a lap was recorded and the distance was known. In the late 1930's the Dooling Brothers .60 cubic inch powered aluminum car called the “Frog” made history as it spun around the track at about 80 miles per hour. Ted’s miniature Frog, dubbed “Tadpole”, is powered by a Cox .01 cubic inch engine with a 2:1 gear ratio driving the rear wheels. It runs on alcohol and 25% nitro-methane for fuel and will achieve speeds of about 30 miles per hour.

177—V12 Air-Cooled OHV Model Aircraft Engine, designed by Martin Ohrendorf, Germany, builder unknown, 2000

This 60-degree, overhead valve V-12 is machined from billet aluminum (bar stock) with cast iron lined cylinders. It has a bore of 21 mm and stroke is 21 mm, making the total displacement 87 cc. It burns methanol on glow ignition and spins its 24/10 propeller at 4,500 RPM. Each carburetor supplies fuel to four opposed cylinders, and the three carburetors are linked together for smooth operation.

To see and hear a similar engine run on YouTube, see http://www.youtube.com/watch?v=mutb7KgA9NM. Despite the massive flywheel, it revs fast and sounds good!

189—“Eldon I 2636” 6-Cylinder, Two-Cycle, In-line Model Boat Engine, deigned by Eldon Dwyer, New Mexico, early 1980s, built by Jim Hawk, Oklahoma, late 1980s. L=13", W=7", H=7"

After building a prototype from bar stock, Dwyer made the patterns and castings to produce a second engine that he used in his power boat in 1982. He started a company called Robotronics that produced and sold a casting kit and drawings for the engine. It is not known how many kits he manufactured and sold, but this example is one of three built by Jim Hawk. It is water cooled (including the exhaust), sports a 120-degree crankshaft and burns methanol on glow ignition. In the early 1990s, the Miniature Engineering Museum acquired the patterns, prototype and Eldon’s power boat engine.

04—14-Cylinder, Twin-Row Radial Engine, 1/8 scale, designed and built by Dennis Fadden, Canada, circa 1996. L=8', W=6", H=7".

The model operates on regular gasoline with spark ignition and swings a 12-inch diameter propeller. Dennis Fadden used cylinder and head castings produced by Bruce Satra, Utah, rather than machining them himself. However, most of Fadden's model engines are machined from bar stock rather than using castings.

Fadden's engines vary from simple single-cylinder model airplane engines to complex in-line and opposed multi-cylinder engines. Fadden also has produced an array of custom designed model inboard and outboard boat motors. he does not produce or use any drawings to create his engines.

The radial engine was originally developed in the 1920's. The model is based on engines built by several manufacturers in the 1930's and 1940's for use in World War II aircraft.

05 and 06—Fadden 1-cylinder and 3-cylinder Engines, designed and built by Dennis Fadden, Canada, early 1990's. L=7", W=6", H=8".

Dennis Fadden designed both the 1-cylinder and the 3-cylinder engines. Bruce Satra, Utah, made the cylinder and head castings for both engines, but Fadden machined the crankcase for the 1-cylinder engine from bar stock (billet) material.

To produce the 3-cylinder radial engine, Fadden made patterns from wood and used the patterns to sand cast the crankcase and gear case from aluminum. Then he machined the castings and internal parts.

Both engines have spark ignition and burn regular gasoline or methanol mixed with oil for lubrication. Most 1-cylinder spark ignition engines utilize a timer assembly (moveable set of points) governed by the crankshaft to trip the coil that fires the spark plug. In a 4-cycle engine, the spark plug fires every revolution, wasting the spark on exhaust fumes. To eliminate this problem in the 1-cylinder engine, Fadden added the camshaft-driven distributor with a rotor to direct the high tension electricity from the coil to the spark plug.

11—Mason "Mastiff" 4-Cylinder Opposed Engine, designed by L.C. Mason, England, built by T.E. Murphy, Phoenix, AZ, 1982. L=13", W=8", H= 9", Weight = 13 lb.

After L.C. Mason designed this water cooled engine he published a book on how to machine and construct a running engine. T.E. Murphy fabricated everything for this dual carburetor version, including his own spark plugs. The engine burns gasoline on spark ignition. it has a 19 mm bore with a 22.2 mm stroke. Total displacement is 24 cc.

22—Loop Aircraft Tachometer, 1/4 scale, designed and built by Pat Loop, Washington, 1995.

Tachometers display the speed of an engine in revolutions per minute (rpm) and this is one of the smallest mechanical tachometers in the world. Pat Loop created this miniature tach to confirm that it could function and display rpm as accurately as a full-size tach. Extensive testing proved that it could. It displayed accurate readings from 0 to 7000 rpm.

Tachometers are usually driven by a flexible shaft or cable attached to the engine's camshaft. Within its mechanism, the rotating shaft generates a magnetic field that creates needle movement as the engine's speed changes. This mechanism can be calibrated so the needle accurately displays the engine's exact running speed.

37—Coholic 3-Cylinder Radial Engine, designed and built by Andrew Coholic, Canada, 1999. L=8", W=4", H=9".

Andrew Coholic created this tiny 2-cycle radial engine by mounting three Cox .049 engines into a common crankcase. The engines are geared together with a common propeller shaft, and they alternately fire every 120 degrees. The carburetor is mounted to a manifold that feeds fuel to each engine upon its intake cycle.

Two-cycle engine usually require pressure in the crankcase to force fuel into the combustion chamber on the intake cycle. The gearing of individual 2-cycle engine together eliminates the need for a pressurized crankcase.

A 1-cylinder, 2-cycle engine produces the necessary pressure as the piston is driven down toward the crankcase from combustion. Since radial engines have pistons traveling away from the crankcase at the same time other pistons travel towards the crankcase, the pressure is cancelled. Therefore, 2-cycle radial engines require a pump or supercharger to increase and maintain pressure in the crankcase during operation.

41—18-Cylinder, Two-row Radial Engine, 1/4 scale, made by Harold Beckett, circa 1995

Harold Becket is a retired United Airlines pilot who handcrafted this engine from drawings provided by Sam and Lee Hodgeson. The model operates on regular gasoline with dual spark ignition. It has a pressurized lubrication system.

The radial engine was much more powerful and reliable than the old rotary design (where the whole engine turns). It was used to power large aircraft such as airliners and bombers. Two-row radials were used extensively in World War II aircraft. The Pratt & Whitney R-1830 (14-cylinder two-row radial) was produced in greater numbers than any piston aircraft engine. it was used in the Consolidated B-24 and PBY-2 as well as the Douglas C-47/DC-3.

In 1939, the Pratt & Whitney R-1830 was installed in the Grumman F4F-3 and was the world's first engine to use a two-stage supercharger—two years ahead of the first two-stage Rolls Royce Merlin V-12 engines.

To see and hear a YouTube video of a single bank 9-cylinder Hodgeson radial engine CLICK HERE. It was built by John Collier. Plans for the 9-cylinder engine can be found at: http://www.agelessengines.com/.

49—Kavan FK50 MKI 2-Cylinder, Opposed Miniature Airplane Engine, designed and built by Franz Kavan, Germany, mid-1980's. L=9", W=11", H=8", Weight = 9 lb-10 oz.

The engine burns methanol on glow ignition. Later production engines became available with a shielded spark ignition. Placing the spark plug wires into a metal casing (braided tubing) eliminates radio interference generated by the spark plugs, essential when flying radio controlled model aircraft.

This is one of the earliest model airplane engines with an oil sump that holds lubricating oil for the crankcase components. This is known as a "splash" oil system. The crankshaft is partially submerged into the oil level in the sump. As it spins, it slings oil throughout the entire crankcase assembly. The upper combustion chamber, rocker arms and valves are lubricated by oil mixed with the fuel.

This engine resembles half of the 4-cylinder Continental C-85 commonly used in the Piper Cub airplane shown below.

54—Continental C-85 Opposed Aircraft Engine, 1/4 scale, built by Dennis Fadden, Canada, circa 1990. L=10", W=10", H=9", Weight = 8lb.

Dennis Fadden's Continental C-85 is a "true-to-scale" model of the full-size version that was commonly used in light aircraft during the post-World War II period—most notably in the Piper Cub.

The model burns gasoline, has a dual spark ignition and a pressurized oil system. Fadden detailed the engine right down to the embossed valve covers and the true-to-scale air cleaner. The crankcase is an aluminum casting produced from hand crafted wooden patterns that Fadden made himself. This C-85 model is the first of only two produced by Dennis Fadden.

63—Satra 0-440 4-cylinder Opposed Model Aircraft Engine, designed and built by Bruce Satra, Utah, mid-1980's.

Bruce Satra engineered and fabricated this 40 cc, 4-cylinder opposed model aircraft engine for a series of construction articles that were published in Strictly IC and Engineering in Miniature magazines.

69—Anzani 3-Cylinder Radial Aircraft Engine, 1/4 scale, designed by Les Chenery, England, built by Roger Butzen, California, circa 1995. L=15", @=23", H=12", Weight = 14 lb-2 oz.

This scale model runs on gasoline with spark ignition and pressurized lubrication system. The cylinders are spaced 120° apart, thus creating a radial configuration. Engine drawings and castings for the crankcase, cylinders and carburetor were provided by Les Chenery.

In the early 1900's, Italian-born Alessandro Anzani began building engines in France. his first success was a 2-cylinder motorcycle engine that established a world speed record in 1905. A few years later, Anzani turned to making an aeroplane engine.

Anzani tried various designs, and then, in 1910 he simply added a third cylinder to his twin cylinder, air-cooled motorcycle engine. he did this by arranging the cylinders first in a fan shape (model engine also on display) and later in radial form. In this way he eliminated the radiator and all water cooling apparatus, reducing engine weight significantly.

73—Schillings 4-Cylinder In-line DOHC Engine, designed and built by Hubert Schillings, Germany, circa 1975. L=11", W=6", H=6", Weight = 7 lb-2 oz.

Hubert Schillings designed several miniature engines from 1970 to 1980. Configurations vary from 1-cylinder aircraft engines to 2-, 3-, 4-, 6- and 8-cylinder inline and V-type engines for both aircraft and automobiles. Most of his engines were machined from aluminum bar stock, but a few were machined from magnesium.

The 4-cylinder in-line dual overhead cam (DOHC) engine has cylinders in a row vertical to the crankshaft. Each cylinder has four valves (two for intake and two for exhaust) to improve performance and efficiency. Two camshafts operate the valves. One camshaft operates the intake valves and the other the exhaust valves, thus "dual overhead cams."

Typically, Schillings used belts to drive the cams rather than gears, but rarely enclosed the belt drive system in a housing as is seen here. It is not known how many of these 4-cylinder DOHC engines he produced.

77—Holt 75 Caterpillar Engine, Model by Reinhold Krieger, Germany, 2001. L=12", W=7", H=10", Weight = 15 lb.

The Holt 75 Caterpillar casting kit was first introduced by Cole's Power Models of Ventura, CA around 1940, but after WWII it lay dormant. Coles re-activated it in 1970 after a new set of patterns was made to comply with the modern foundry practices. It is a 4-cylinder, 4-cycle, water cooled in-line engine that was, in full size, most successfully used in tanks of WWI. The speed of the engine is controlled by a centrifugal fly-ball governor that was commonly used for governing the speed of steam engines. The model engine has a bore of 1 inch and a stroke of 1-1/4". The crankcase holds the lubricating oil that is distributed by the crankshaft as it spins, but external rocker arms must be manually lubricated before operating the engine. it is water cooled and burns gasoline using a spark ignition.

(See http://www.youtube.com/watch?v=tl0nD1smbAg&feature=related and http://www.youtube.com/watch?v=AjQLKLaDOTY&feature=related for two videos of Holt engines (not this particular one) being run.)

79—Wall Duplex Mariner, built by Elmer A. Wall, circa 1940-41. L=9", W=6", H=8".

Elmer A. Wall, an engineer/inventor of considerable ability, operated a motor car manufacturing company in Chicago before Ford made his Model "T." He also designed and built an electrical power system supplying part of the city before Consolidated Edison existed. He had many associates in the engineering profession in this country and abroad. During the depression he began designing and manufacturing casting kits for miniature internal combustion engines such as this Duplex Mariner.

Wall's Model Engine Laboratory was located in Chicago, IL and the catalog cover read:

"Build Your Model Internal Combustion Engines with

WALL CASTINGS and DETAILED DRAWINGS

on your own lathe in your own work shop.

Easy to Build and Interesting to Run.

Suitable for Model Aircraft and

Record-Breaking Model Power Boats.

Also

Has it ever occurred to you that in buying these construction sets you are purchasing knowledge which has taken some other man, an expert at his job, a lifetime to acquire?"

86—Miniature 7-Cylinder Radial Engine, designed and built by Pius Job, Switzerland, 1993. L=10", W=9", H=15" (on stand).

Pius Job, a Swiss engineer, worked for Esec USA when he fabricated this engine from aircraft grade aluminum and steel. The lightweight aluminum cylinders are lined with cast iron sleeves to support ringed pistons, and the crankshaft and cam ring ride in ball bearings. it burns methanol (with oil mixed in for lubrication) on glow ignition and turns a 24-10 propeller at 6,000 rpm. The external rocker arms require manual lubrication before operating the engine.

98—Fadden 1-Cylinder Model Airplane Engine, designed by Bruce Satra, Utah, 2000 and built by Dennis Fadden, Canada, 2002. L-5", W=4", H=5".

Dennis Fadden built this model engine using castings made by Bruce Satra. The cylinder and head assembly is from a 1/6 scale model of the Pratt & Whitney R-985 Wasp Jr. 9-cylinder engine that Satra manufactures and sells as a kit.

Utilizing just one cylinder assembly, Satra designed and engineered this new product. After machining his first engines from aluminum bar stock, Satra produced castings for the crankcase and began selling this little single Pratt in kit form too.

100—Anzani 3-Cylinder Fan Engine, 1/4 scale, designed by Alfred Eichinger, Austria, custom built in Ukraine, 2002. L-8", W=12", H=9", Weight = 3 lb- 13 oz.

The automatic inlet valves are situated inside the head where the intake pipe connects. The exhaust valves are mechanically operated at the back of the combustion chamber. The model has spark ignition and burns gasoline mixed with oil for lubrication.

In 1910, Italian born Alessandro Anzani added a third cylinder to his twin-cylinder, air-cooled motorcycle engine to create this fan-type aircraft engine. Anzani's fan engine carried Frenchman Louis Blériot in his monoplane over the English Channel in 1909—the world's first flight over a large body of water in a "heavier-than-air" craft.

Anzani later revised the fan design moving the three cylinders from above the centerline into a radial design. The three cylinders were spaced 120° apart for smother operation. this is one of six Alfred Eichinger models custom built in the Ukraine in 2002.

106—1-Cylinder, 4-Cycle Model Boat Motor, designed and built by Henry Parohl, NY, 1960's. L=5", W=4", H=4".

“On September 8, 1935 at the annual Walter Elliot Memorial Race in New York’s Central Park, Henry was crowned a new champion when his gas driven Elanor 2 powerboat was clocked at 26.77 mph in 5 laps around a 750 foot circular coarse. The precision necessary in the construction of the motor was nothing new to the owner, who in private life, was a craftsman making tiny dies for a wrist watch company.”

   —From The Model Craftsman, November, 1935

Little information is known about Henry Parohl’s engines, but most were designed to power model boats.  It is estimated he built about 350 model engines of varying configurations from single-cylinder 2and 4-cycle engines to complex multi-cylinder boat and airplane engines. Toward the end of his model engine building career he designed and constructed a few model (Mazda type) rotary engines and began to fabricate a small jet engine. 

121—Supercharged Thunderbird Miniature Engine, manufactured by Scott Motors, Inc., Arizona, 1940s. L=6", W=3", H=6".

In 1946, the Thunderbird was advertised as the only miniature engine with a genuine supercharger, “just like the big ones!” Supercharging increases atmospheric pressure in the engine to produce more horsepower.

The ad described the engine as “the perfect racing engine for airplanes, cars and boats.”

Scott Motors, Inc., was located at Sky Harbor Airport. It was owned by John Connelly and Leland Hayward. Connelly ran the aircraft overhaul facility at the airport and Hayward had some connection with the airline industry. The company was named after Connelly’s son, Scott.

123—Wankel (Mazda Type) Rotary Engine, model designed and built by Henry Parohl, NY, 1960s. L=6", W=7", H=6".

Henry Parohl miniaturized almost every configuration of internal combustion engine that was invented, including this Wankel (Mazda type) rotary engine. It is a two-cycle engine that burns gasoline with oil mixed in for lubrication. The tank sits above the engine and the fuel is gravity fed into carburetor’s float bowl (cylindrical tank next to the carburetor. The float bowl retains a steady level of fuel and maintains constant pressure for the fuel available to the carburetor. The spark for the ignition is provided by an external battery and coil.

125—Parohl Single-Cylinder, Overhead Valve (OHV) 4-valve Model Boat Engine, designed and built by Henry Parohl, New York, 1960s. L=9", W=9", H=10".

To gain efficiency and performance Henry Parohl installed 4 valves in the head of this engine. The two rocker-arm shafts are controlled by a single camshaft behind, and at the base of the cylinder. Gasoline is gravity fed into the float bowl (of carburetor), which maintains a constant pressure and steady volume of fuel available to the carburetor. Lubrication is accomplished by gravity from a small transparent reservoir that the operator must fill before running the engine. It is located behind the fuel tank and slowly meters oil from the reservoir into the engine for lubrication during operation. The rocker-arms and shafts must be manually lubricated before running the engine. Typically model air-cooled engines are designed for aircraft, but Parohl fitted this one with a flywheel and rope-start pulley for a model powerboat or automobile.

130—Fadden .010 Outboard Boat Motor, designed and built by Dennis Fadden, Canada, 2005. L=3", W=1", H=3.5"

This is one of two miniature boat motors Dennis Fadden machined from bar stock that incorporated a Cox .010 engine. Because of the complex contours and radii of the lower end, most were hand formed. First, material is removed by rough machining on conventional equipment with straight linear cuts. Then, the contours are created by hand with files. It’s precise, requiring a good eye, patience and a tremendous amount of time.

142—Racing Thunderbird (Hayward-Connelly), manufactured by Scott Motors, Inc., 1940’s. L=5", W=4, H=6".

Scott Motors, Inc., was located at Sky Harbor Airport in Phoenix, AZ. It was owned by John Connelly and Leland Hayward.  Connelly ran the aircraft overhaul facility at the airport and Hayward had some connection with the airline industry. The company was named after Connelly’s son, Scott. The Racing Thunderbird engines were developed and tested in the Phoenix facility, but it is not known if any were actually sold between 1946 and 1948 when the company relocated to the San Francisco Municipal Airport. Just as production was getting underway on the Racing Thunderbird a fire destroyed much of the manufacturing facility, which put a halt to continued work. 

At that time, the introduction of the glow plug made the already manufactured parts and engines obsolete; combined with tumbling prices for model airplane engines Scott Motors closed its doors forever.

154—Boxer 2-Cylinder Opposed Aircraft Engine, designed and built by unknown maker, Germany, unknown date. L=9", W=9", H=7"

The 4-cyle engine appears to be made from castings, but was actually constructed from aluminum, brass and steel bar stock. Much of it was roughed out on conventional machine shop equipment. Many hours were spent hand-forming the parts using files and scrapers. The finish was applied by glass beading the surfaces and then nickel-plating the steel parts, such as the rocker arms and propeller hub.

The most unique feature is two exhaust ports for each cylinder. This was accomplished by drilling into the head from the front, cross drilling from the top to the bottom, and then plugging the original hole ahead of the exhaust pipes.

Someone in Germany restored this engine for display. For a finishing touch, he plated the steel exhaust pipes with chrome and then heated them with a torch until blue. This gives the appearance that the engine has been run since the restoration.

167—K-35 Single-Cylinder, Two Cycle Model Airplane Engine, designed and built by Fred Kunze, Arizona, 1975. L=8", W=4", H=5"

Fred constructed and sold 39 of his model K-35 airplane engine. It has a 13/16 inch bore, 3/4 inch stroke, and burns methanol on glow ignition. It swings a 12-6 propeller over 8, 000 revolutions per minute.

168—Supercharged V-8 Racing Engine, designed and built by James Weber, Riverton, Wyoming, 2004.

Closely resembling the Chrysler 300 ‘Hemi’ from the early 60s this 1/3-scale model has a 1.0 inch bore and .900 inch stroke for a total displacement of 5.65 cubic inches. The engine burns gasoline or methanol (methyl alcohol) on dual electronic spark ignition and incorporates a two-stage pressurized dry-sump lubrication system. His custom designed Roots type sliding-vane supercharger with dual carburetors pushes the engine speed to 12,000 revolutions per minute.

James spent 5 years in the design and development of this engine and it is machined entirely from aircraft grade aluminum and steel bar stock. He is a self-taught machinist who honed his skills and techniques within his home machine shop. His quest is to educate and encourage others to learn machining and enter into the world of miniature engineering.  Visit his site or contact him at: www.weberprecision.com

172—Vega 50 T Two-Cylinder, Opposed Model Airplane Engine, manufactured by J.C. Harbone, England, 1980. L=7", W=7", H=5".

The valves, lifters, and pushrods are integral within the finned portion of the cylinders giving it the appearance of a 2-cycle engine. In reality it is an 8.5 cc four-cycle, side-valve (or flat-head) two cylinder aircraft engine that burns methanol (methyl alcohol) on glow ignition. The valves are positioned parallel to and behind the cylinder rather than above the cylinder and inside the heads.

174—Single-Cylinder, Air-Cooled, Four Cycle OHV Engine, United Kingdom, builder unknown, date unknown. L=5", W=12", H=9".

 The striking features of this engine are the complexity of the carburetor and the use of only one threaded stud to mount both the intake and exhaust manifold. The crankcase is filled with motor oil for internal splash lubrication; however the unusual overhead rocker and valve assembly must be manually lubricated before operation. It burns gasoline on spark ignition and the large Bosch spark plug indicates it may have been built in the early 1920s or 30s.

175—Three-Cylinder, Air-Cooled, Radial Model Airplane Engine, United Kingdom, Builder unknown, date unknown. L=5", W=12", W=9", Weight = 7 lb.

This radial engine features a single rocker box that houses both the intake and exhaust rockers and uses only one large tube to enclose both pushrods. It has a bore of approximately 1 inch and a stroke of 1 inch for a total displacement of about 2.35 cubic inches. It runs on a home made electronic spark ignition and burns gasoline or methanol with oil mixed in for lubrication.

178—Hawk 40, Single Cylinder, Air-Cooled Aircraft Engine, designed and built by G. Punter, Australia, 1976

Mr. Punter made his own molds and die cast the parts for this air-cooled aircraft engine. Die casting differs from sand casting in that the molds are made of steel and the molten metal is injected into the molds under high pressure. He built only four of these engines between 1976 and 1980 and each took approximately 150 hours to complete; this does not include the dies for casting. The first engine took over 400 hours from design to a working engine. It has a 7/8 inch bore, 11/16 inch stroke, weighs about 14 ounces and burns methanol on glow ignition.

179—“Water Witch” Single-Cylinder Marine Engine, built by Dick Pretel, California, circa 1983.

Dick’s passion was racing model boats and when it came to building his own engine he started with a set of “Water Witch” castings. Unhappy with the Westbury design he made several engineering changes, which include a custom machined hollow sleeve that he sealed to the cylinder so water could be circulated through it for better cooling. Another innovation is his uniquely machined engine mount that doubles as a high-capacity oil reservoir. Finally he machined a light-weight aluminum connecting rod and piston that was engineered to increase compression. It burns gasoline on spark ignition and it is the first model engine Pretel built.   

180—“Gannet” Single-Cylinder, Water-Cooled Marine Engine, built by Gannet Engines, England, 1960s, modified by Dick Petrel, California 1997

Dick Pretel’s demand for more performance from his model racing boats led him to several modifications to this popular English built marine engine. He designed and constructed a light weight aluminum connecting rod and developed a new piston to increase compression. His newly designed head included 4 valves and an extra exhaust pipe for better breathing and the carburetor was extended on a riser for better fuel efficiency. Increased performance means increased heat, so Dick hollowed out the head for water cooling to circumvent the increases in temperature.                                  

181—“KEN”, Single Cylinder, Air-Cooled Marine Engine, designed by Ken Brennerman Oakland CA 1938, built by Dick Pretel, 2003

From approximately six sets of castings made by Ken Brennerman in the mid 30's this is the only known surviving engine. A set of partially machined castings was found at a garage sale in California in 2002 and eventually ended up with Dick Pretel. Aware of Ken Brennerman and the history of his engine, Dick decided to complete the castings to represent the original but incorporate more modern engineering and machining techniques. This single-cylinder overhead valve engine burns gasoline on spark ignition.

185—Schillings 6-Cylinder, In-line DOHC Engine, designed by Hubert Schillings, built by Rolf Luther 1998

Hubert Schillings designed several miniature engines from 1970 to 1980. Configurations vary from 1-cylinder aircraft engines to 2-, 3-, 4-, 6- and 8-cylinder V-type and inline engines for both aircraft and automobiles. Most of his engines are machined from aluminum bar stock (ingot).

This 6-cylinder Inline Dual Overhead Cam (DOHC) design has cylinders laid out in a straight line with two camshafts that operate the valves. One camshaft operates the intake valves and the other camshaft operates the exhaust valves, thus the description “dual overhead cams.”

Typically, Schillings used belts to drive the cams rather than gears, but most unusual about this model is the use of spark ignition.  It is believed that Rolf Luther completed only three or four of these inline engines and this is the only example known to have spark ignition.

186—Wasp Jr., Single-Cylinder Model Airplane Engine, designed and built by Bruce Satra, Vernal UT, 2000

Bruce Satra of Vernal Engineering produces a very popular casting kit for the 1/6-scale Pratt Whitney Wasp Jr. Radial engine. In this example he combined one of the Wasp cylinder assemblies to a crankcase he machined from billet to produce this single-cylinder Wasp Jr. engine. It is designed to burn gasoline or methanol on spark ignition.

187—100cc Two-Cylinder, Two-Cycle, Opposed Aircraft Engine, Designer/Builder Unknown, Germany, 1985. L=15", W=16", H=22"

Commercially available cylinders, possibly from a motorcycle were used to produce this aircraft engine. The Tilloston carburetor is designed for gasoline, but the spark plug holes were adapted for model engine glow plugs, indicative of a methanol burning engine. The crankcase appears to be cast from aluminum, but quite possibly was machined from billet material. The engine was built in Germany in 1985, but the designer and builder are unknown.

192—Edwards FA90-3 3-Cylinder Radial Aircraft Engine, designed and built by Forest Edwards, California, 1981. L=8", W=8", H=9", Weight = 1 lb-12 oz

This is Forest Edwards’ first home-made model airplane engine. He utilized the cylinder heads and cams from three Saito FA-30 single cylinder model airplane engines to produce this radial. All other components were machined from bar stock. It burns methanol with castor oil mixed in, but the exposed rocker arms required manual lubrication before operation. Its performance was good with smooth running characteristics throughout the full operating range of speeds.

Before completing this engine Edwards had already produced several drawings and begun to fabricate a much larger 5-cylinder radial that he would machine entirely from bar stock. Over the next 12 years he produced 30 five-cylinder, spark ignition radial engines.

193—1/4 Scale Caminez 4-Cylinder Radial Aircraft Engine, designed and built by Wally Warner, MI, 2007. L=10", W=8", H=9", Weight = 7 lb-5 oz

The full-size engine was developed and patented by Harold Caminez in the mid 20's. The early engines were advertised as producing 150 hp at 1200 rpm, however by the time the engine was awarded the Engine Approved Certificate in June 1928, it was rated at 120 hp at 960 rpm. Boeing built two Model 81 trainers to use the Caminez engine and the first one flew in March of 1928. Apparently the engine simply didn’t stand up in an operational environment and other manufacturers dropped the Caminez as an option for their aircraft. One report states the engine vibrated excessively and future plans to market the engine were abandoned in 1929. Wally Warner started this model project in 1982 and finally found the opportunity to finish it in 2007.

194—JENNO 14 Single-Cylinder Model Airplane Engine, designed and built by Larry Jenno, NV, 1943. L=3", W=2", H=3", Weight = 8 oz

Larry Jenno is well known for his reproduction “old-timer” spark ignition engines from the early 40s and 50s, but his first home-made  engine is this .14 cu. in., single-cylinder, two-cycle model airplane engine. He carved the patterns from wood and cast the crankcase, cylinder and backplate from aluminum in his home machine shop.  It runs on spark ignition and burns methanol (methyl alcohol) with caster oil mixed in for lubrication. This is the only example of the Jenno14 that he produced.

196—ROSS Two-Cylinder, Two-Cycle Target Drone Engine, designed and built  by Lou Ross, AZ, 1973

In the early 70's, Lou Ross designed and developed this large 3.5 cubic inch opposed twin for possible use as a target drone engine for military applications. It burns methanol on glow ignition with castor oil mixed in for lubrication. His unique style of casting the crankcase integral with the cylinders is typical of his line of smaller model airplane engines that are well known among the collectors, however, only a few examples of these larger drone engines exist today. 

197—ROSS Four-Cylinder, Two-Cycle, Target Drone Engine, designed and built  by Lou Ross, AZ, 1972

In the early 70s Lou Ross designed and developed a couple of large multi-cylinder engines for military applications as target drone power plants. This is a 7.0 cubic inch opposed four cylinder, two-cycle designed to burn methanol on glow ignition. The glow ignition eliminates the need for points, coils, and heavy batteries allowing the drone to carry more fuel for long distance flight. His 3.5 cubic inch two-cylinder drone engine is most desirable for smaller target drones and high speeds. He cast the crankcase integral with the cylinders in these engines, which is typical of his much smaller model airplane engines. His line of model airplane engines is highly collectible today; however, only a few examples of these large drone engines were produced. 

198—KING “T85”  Two-Cylinder, Four-Cycle,  Air-Cooled Engine, designed and built by Stephen J. King, FL, 2005. L=10", W=6", H=7", Weight = 5 lb 

Mr. King designed this two-cylinder engine with an open crankcase for visual effect while the engine is operating. It burns gasoline on spark ignition and utilizes a pressurized oil system to lubricate the crank, rod, and cam bearings. Open rockers on top require manual lubrication. It has a bore of 19 mm and a stroke of 15 mm and burns regular gasoline on electronic spark ignition. The tiny float bowls under the carburetors provide stability to the constant stream of fuel entering the carburetors. Other unique accessories include a starter and a small generator.

200—KING “741” Seven-Cylinder, Two-Cycle, Air-Cooled Radial Airplane Engine, designed and built by Stephen J. King, FL, 2007. L=8", W=8", H=9", Weight = 6 lb-5 oz

Similar in appearance to the “Gnome” rotary engines of WWI, this two-cycle radial engine has mechanically driven intake valves with a single pushrod in front of each cylinder. It has a bore of .750 inch and stroke of .800 inch, incorporates a high-speed supercharger to increase crankcase pressure for fuel delivery to the cylinders. It runs on glow ignition, but unlike most two-cycle engines this one sports a dry-sump, pressure-fed oil system for internal lubrication, eliminating the need to mix oil with the fuel.

201—“RCS 400 5-Cylinder Radial Airplane Engine, designed and manufactured by Moki, Inc., Ukraine, 2007. Size=14" dia.

This 400 cc radial burns a gasoline/oil mixture on spark ignition. The unique electronic ignition utilizes a miniature high tension coil located at each spark plug. This "coil-on-plug" concept eliminates the need for a distributor since only low voltage is sent from the ignition module and is converted to high voltage at each spark plug. A magnetic sensor on the crankshaft or camshaft is used for timing the spark sequence. The engine measures about 14" in diameter, weighs 20.5 pounds (without display base) and produces 25 horsepower spinning a 40-25 propeller at 3800 rpm.

202—SATRA ‘R-5’ Model Radial Airplane Engine, designed and built by Bruce Satra, UT, 1984. L=8", W=6", H=7", Weight = 2 lb-6 oz

Intrigued by the Morton M5, Bruce considered it to be of sound design, but felt it lacked structural integrity inside. His quest to produce a more robust engine led him to this design that he dubbed the Satra R-5. The bore is .700 and stroke .625 making the total displacement 1.2 cubic inches compared to the Morton M5’s bore of .625 and stroke of .600 totaling only .920 cubic inches.  This engine burns methanol on spark ignition and turns a 15-6 propeller at 6500 revolutions per minute.  Unlike the Morton M5 Bruce utilized enclosed rocker boxes eliminating the need for manually lubricating the rocker arms before operation.

203—SATRA 0-440, 4-Cylinder Opposed Model Airplane Engine, designed and built by Bruce Satra, UT, mid 1980s. L=11", W=8", H=7"

This 0-440 differs from his first one in that it burns gasoline on spark ignition rather than methanol on glow ignition. He produced the tooling and molded the distributor cap from bakelite, just like the full-size engines With a bore of .937 and stroke of .875, its 2.4 cubic inch displacement develops in excess of 2 horsepower. It is machined entirely from aircraft grade aluminum bar stock.

204—(Upper left) .098 Vertical 2-Cylinder, 2-Cycle Aero Engine, designed and fabricated by John Swartzwelder, WA, mid 1970's. Weight = 8 oz

While working in the "wind tunnel" model shop at Boeing, John fabricated several small multi-cylinder aircraft engines from commercially available Cox .049, .020, and .010 cc model airplane engines. Some were simply geared together via a common propeller shaft and custom engine mount, while others required engineering sophisticated crankcases with specially designed crankshafts. They burn methanol (methyl alcohol) with castor oil mixed in for lubrication.

205—(Lower left) .098 Opposed 2-Cylinder, 2-Cycle Aero Engine, designed and fabricated by John Swartzwelder, WA, mid 1970's

206—(Middle, upper row) .040 Opposed 2-Cylinder, 2-Cycle Aero Engine, designed and fabricated by John Swartzwelder, WA, mid 1970's

207—(Far right) .020 Opposed 2-Cylinder, 2-Cycle Aero Engine, designed and fabricated by John Swartzwelder, WA, mid 1970's.

208—Springfield A.1 Single-cylinder, Two-cycle Model Engine, designed and fabricated by Roy E. McAdams, Springfield, OH, circa 1919. L=4.75", W=4", H=4.75" (w/o glow plug), Base=6" x 6", Weight = 8 oz.

McAdams offered the A-1 in kit form or completely assembled and ready to run. Two other variations offered were an opposed 2-cylinder and a 5-chlinder radial. The cost for a completed A-1 was $25.00, an A-2 Twin was $75.00 and the A-5 radial was $500.00.  With a bore of 1.25" and a stroke of 1.0" the engines could be built to burn gasoline or "house gas" (natural gas) on spark ignition. This example indicates it was constructed for natural gas, which required supplemental oiling via oil-cups on the bearing journals. Typically the spark plugs were re-worked from large plugs or home built using glass tubing filled with plaster of Paris for the insulator.

Model Pratt & Whitney Engine Casting—A 4-part casting for a 9-cylinder Pratt & Whitney R985 engine is displayed here so you can see some of the craftsmanship that goes into the design of an engine like this. Much of the fine machine work of the basic engine casting is covered up once the cylinders and other parts are bolted on. This assembly represents many hours of work in pattern making, casting and finished machining.

18—Morton M5 5-Cylinder Radial Engine, designed and built by Morton Aviation, Kearney, NB, 1949. L=7", W=15", H=6"

The M5 was originally manufactured in the 1940's and was the first miniature radial engine made for model airplanes. It was designed by Glen Morton and was based on the full-size LeBlond radial aircraft engines made in 1928. The radial engine was much more powerful and reliable than the old rotary design and was used to power large aircraft such as airliners and World War II-era bombers.

35—Cirrus 4-Cylinder, Water-cooled, In-line Model Airplane Engine, 1/6 scale model built by Merritt Zimmerman, 1980-1994. L=7", W=3", H=5".

Merritt Zimmerman produced his own castings to build (75) 1/6 scale Cirrus engines (glow ignition) between about 1980 and 1994. He sold many more castings in kit form for miniature engine builders during the same period. To differentiate  his engines from those built by others, an oval shaped embossed emblem with the name "ZH Cirrus" was bonded to the crankcase identifying those engines completed by him. The oval emblem was not sold or included in any of the kits.

Eight of the seventy five engines were water-cooled. In the water-cooled engine the cylinders are mounted within an aluminum block so water can circulate through the block (around the cylinders) and up into the head. The head is machined in one piece with internal water passages to carry water from the cylinder block into the radiator.

39—27-25 Propeller for 1/4 scale Bentley BR-2 Rotary Airplane Engine, built by Robert Cooper, Savannah, GA, 1997. L=28", W=4", H=2".

Robert Cooper laminated the wood together just as it was done in the early days of flight with the use of home made horsehide glue. Once bonded, the propeller was hand carved until each half matched. Then it was balanced by inserting weights into the center hub.

This scale model is based on the propeller used with a Bentley B2 rotary airplane engine in a World War I Sopwith Snipe airplane. It is designated a 27-25 propeller. The first number denotes the propeller's length, and the second number is its pitch (inches the propeller travels through the air per revolution without a load).

42—Otter 30 4-Cylinder In-line Boat Engine, Designed by Dr. Haydock, England, mid-1970's. L=11", W=8", H=20".

Dr. Haydock (first name unknown) designed 1-cylinder, 2-cylinder and 4-cylinder engines fro model boats. He built a handful of otter 30 cc engines from his own patterns and castings. All engines were sold as completed engines and not as kits.

The red distributor cap is fabricated from a plastic bottle cap not unlike a liquid dish-washing soap bottle. It is mounted to a movable bracket for manual timing and spark advance at higher speeds

46—JPX T240 Turbojet Model Aircraft Engine, built in France, circa 1992. L=15", W=6", H=6".

Practical gas turbine power for model aircraft became a reality when Bryan Seegers of Arizona made model aviation history in 1988. He flew what is believed to be the world's first miniature turbojet-powered aircraft

By 1992, commercially available miniature jet engines like this JPX-T240 began to appear on the market. This engine burns propane fuel and can produce up to 13 pounds of thrust. Today's model jet engine burn gasoline or jet fuel and produce several times more thrust.

The first jet full-size jet plane, a Heinkel He 778 flew in 1939. A jet engine has no propeller. It sucks in air at one end and burns it with fuel. Hot gasses blast out the other end, thrusting the aircraft forward.

58—U-22 Turbojet Model Aircraft Engine, built by Dennis Fadden, Canada, circa 1980

For many years, the idea of a functional miniature jet engine intrigued modelers. In his early years of engineering, Dennis Fadden built this model jet engine from plans that were probably from the 1950's. The model was advertised as having "real compressor and power turbine stages, 8 separate combustion chambers and an afterburner that goes in with a bang!" Supposedly, the finished engine would perform like a full-size jet engine, but it turned out to be a failure. However, this engine was probably most responsible for young engineers continuing pursuit of a functional miniature jet engine.

64—Red Wing Stationary Engine, built by Harold Beckett, Longmont, CO, circa mid-1990's. L=17", W=11", H=13"

The Red Wing stationary engines made in Red Wing, MN were commonly used to power industrial machinery and farm equipment in the early 1900's. Harold Beckett built this 1/4 scale model of the Red Wing from a casting kit. It has a bore of 1.125", a 2" stroke and burns gasoline on spark ignition. The cylinder passes through the large reservoir in the front which is filled with water for cooling. Stationary engines require manual lubrication before operation and have several oil and grease cups that require re-filling periodically while the engine is in operation.

Stationary engines run a slow speeds (500-600 rpm and rely on their massive flywheels to store the energy necessary to power machinery and equipment.

68—Jupiter 220 2-Clinder Opposed Model Airplane Engine, manufactured by Farger & Joosten, Germany, early 1980's. L=9", W=11", H=6"

These belt-driven, overhead camshaft engines (that also were available in a 1-cylinder version) are superbly engineered but quite heavy, so not practical for competitive flying. Despite the  37 cc capacity, the power output was considered low. The power could be increased with re-profiled camshafts, different plugs and added piston rings. (To re-profile means to machine a different shape to the cams to change when the intake and exhaust valves open and close.) This drastically affects the engine's performance.

Unlike its competitors, the Jupiter was entirely machined from bar tock and no castings were used. The lack of performance and added expense of machining from ingot probably created the lack of sales.

78—Miniature 3-Cylinder Radial Engine, designed and machined by Cliff Bumpus, circa 1994. L=7", W=11", H=10"

Cliff Bumpus machined the engine from bar stock (aluminum ingots). The cylinders are spaced 120° apart in a circular pattern, typical for a 3-cyinder radial configuration. The miniature runs on glow plugs rather than spark plugs. The combustion of the fuel in the engine keeps the glow plug hot between cycles, so it does not need to be regulated or powered while the engine is running like a spark plug would.

The methyl alcohol fuel is mixed with castor oil which lubricates the internal engine parts. Since castor oil is not flammable, lubrication can occur before or after combustion, depending on the design of the engine. In either case, the excess castor oil is discharged from the engine during operation.

80—3-Cylinder Radial Model Aircraft Engine, designed and built by Henry Parohl, New York, circa 1960. L=9", W=12", H=9"

In the early 1930's, Henry Parohl was setting records with his model powerboats and homemade miniature engines—two-and four-cycle singles and twins. Then he began designing more complex three- and five-cylinder radial aircraft engines. Although the radials are quite a change from his early boat engines, Parohl's building technique and style have been retained throughout his engine building career.

This 3-cylinder radial is a one-of-a-kind custom design that runs on regular gasoline and has a spark ignition.

83—Miniature 7-Cylinder Radial Engine, designed and built by Pierre Blais, Canada, 1990. L-10", W=11", H=12"

Pierre Blais' engine burns a methanol/castor oil mixture on glow ignition. The combustion of the fuel keeps the glow plug hot between cycles, so the plug does not need to be regulated or powered while the engine is running like a spark plug does.

The methanol is burned, but since the castor oil is not flammable, it is discharged in liquid form The castor oil in the fuel lubricates the internal parts before it is sent into the combustion chamber. However, the carburetor is in back and little oil reaches the cams in the front nose case. Blais solved the problem by sealing off the nose case from the crankcase and filling it with motor oil.

94—Ford Model "A" 4-Cylinder Automobile Engine, 1/5 scale replica by Profi M. E., Ukraine, 2002. L=8", W=6", H=7"

This scale replica of the 4-cycle, water-cooled engine in the famous Ford Model "A" automobile of 1928 has a bore of .675" and a stroke if .827". Total displacement is .30 cubic inches.

Castings were made for the crankcase, head and oil pan, and bar stock was machined for the crankshaft and camshaft. The engine will burn gasoline or methanol on spark ignition, and it contains oil in the oil pan for lubrication. Internal lubrication is a splash system that relies on the crankshaft to splash (sling) the oil within the crankcase when it rotates.

The engine was custom manufactured for an American automobile buff. Paul Knapp designed and fabricated the spark plugs.

Approximately 25 Model "A" engine replicas were produced in this "factory stock" configuration, a copy of the original factory engine as sold in the Model "A". Several months after the introduction of this model engine, approximately 25 modified "Hotrod" versions were produced that included a finned racing head and dual carburetors.

99—1937 Harley Davidson "Knucklehead" Motorcycle Engine, 1/4 scale model built by Replica Engines, Michigan, circa 1997. L=9", W=9" H=9"

The model is a 2-cylinder, 45° V overhead valve configuration that burns gasoline or methanol. It utilizes two oil pumps for pressurized dry sump lubrication with a small amount of oil mixed into the fuel for piston and valve lubrication. It has a .75" bore, .875" stroke and operates on spark ignition.

101—Miniature 7-Cylinder Radial Engine, designed and built by Lee Root, circa 1975. (Courtesy of Margarita and Al Root, and Rhetta and John Hopfauf)

Lee Root's engines have inspired enthusiasts, hobbyists and miniature engine builders throughout the world. Although parts of his engines appear to be castings, they were machined entirely from bar stock. Root's 7-cylinder radial was ahead of its time and more advanced than most miniature engines made today.

Root is perhaps best known for his custom designed miniature Stromberg-type carburetor with an automatic choke and accelerator pump, a dry sump lubrication system and an electric fuel  pump.

102—Chevrolet Corvette Small Block V-8 Engine, designed and built by Lee Root, Washington, 1980's. L=13", W=9", H=9". (Courtesy of Margarita and Al Root, and Rhetta and John Hopfauf.)

Lee Root machined 7075 aircraft grade aluminum to produce the crankcase, heads, rods and pistons, and there are no castings used in the engine. The cylinder liners are cast iron, the crankshaft and cam are heat-treated 4340 steel. He used a full-size corvette racing cam for the cam profiles.

Construction of scale rocker arms proved to be the greatest challenge; however, he conceded the carburetor and electronic ignition were problem areas as well. Lee developed an electronic balancer to balance the engine and preliminary tests showed the engine to exceed 10,000 RPM.

103—Ford Model "A" Engine, designed and built by Lee Root, Washington, circa 1980's. L=11", W=6", H=10". (Courtesy of Margarita and Al Root, and Rhetta and John Hopfauf.)

Lee Root produced this scale replica of the four-cylinder, water-cooled engine used in the famous Ford Model "A" automobile of 1928. The engine is machined from 7075 aircraft grade aluminum and clear anodized for the color and finish. He never made drawings for his engines, but always worked from sketches and notes plus his imagination. It is a 4-cylinder, water-cooled, side valve (the valves are located in the crankcase next to the cylinders) engine with a 180° crankshaft. The model engine burns gasoline on spark ignition and supports and internal pressurized oiling system. There are no castings used in this engine.

104—The "Root Special" DOHC 4-Cylinder Racing Engine, designed and built by Lee Root, Washington, 1980's. L=11", W=8", H=8". (Courtesy of Margarita and Al Root, and Rhetta and John Hopfauf.)

Lee Root needed a small 4-cylinder engine to test a miniature electronic throttle-body fuel injection system he was developing. he worked from his imagination and produced no drawings for this engine. His water-cooled race engine has a bore of .875" and a stroke of .75" for a total displacement of 1.8 cubic inches. It burns gasoline for fuel, utilizes pressure lubrication and sports his highly successful, electronic throttle-body fuel injection on spark ignition.

The "Root Special" is machined entirely from 7075 aluminum bar stock and utilizes no castings. The aluminum parts were clear anodized to produce the color and finish. The second photo shows the side of the engine featuring Lee's unique fuel injection system.

107—5-Cylinder Radial Model Aircraft Engine, designed and built by Henry Parohl, New York, circa 1960. L=11", W=10", H=9"

Most of Henry Parohl's engines incorporated gravity fed lubrication systems. Prior to running the engine, the operator would fill the small, transparent reservoir ahead of the number one (top) cylinder with motor oil. Then, with its spark ignition turned on, the engine would run on regular gasoline. The oil would slowly feed from the reservoir into the engine for lubrication.

This model is believed to be the only 5-cylinder radial engine that Parohl designed and built. It is not known if Parohl worked from drawings or sketches, but none have been located.

117—Erickson FE200 (MMC) Prototype Migrating Combustion Chamber Engine, manufactured by Erickson Motors, Indiana, circa 1993. L=9", W=8", H=7".

This engine has a square piston inside a square cylinder. Both migrate about the crankcase as it rotates. The piston slides up and down inside the cylinder as it slides left to right inside the crankcase.

The migrating combustion chamber allows this unique engine to take full advantage of the gas expansion after combustion. By the time the exhaust is released to the atmosphere it has expanded to its fullest and is almost completely depleted of pressure. The exhaust temperature is not much higher than ambient air.

This 200 cc prototype was CNC machined from bar stock. Later production engines were made smaller (120 cc) and made from castings.

See http://www.ericksonmotors.com/mccsim.htm for an animation and diagrams as to how the MMC engine works. It is much easier to understand how it works after you see the animation.

119—Schillings 6-Cylinder Opposed DOHC Miniature Engine, designed and built by Hubert Schillings, Germany, circa 1975. L=9", W=9", H=7".

Hubert Schillings designed several miniature engines from 1970 to 1980. Configurations vary from 1-cylinder aircraft engines to 2-, 3-, 4-, 6- and 8-cylinder V-type engines for both aircraft and automobiles. Most of his engines are machined from aluminum bar stock (ingot).

129—Gannet Single-Cylinder Four-Cycle Model Airplane Engine, manufactured by Gannet Engineering, England, 1960's. L=8", W=7", H=7".

It is estimated that only about twenty air-cooled model airplane engines were built by Gannet Engineering and this is one of only a few equipped with a magneto. It burns gasoline with a little oil mixed in for piston and valve lubrication, but the open rocker arms required manual lubrication before operation. The cylindrical reservoir in the front slowly feeds oil to the internal components while the crankshaft is turning.

137—Magnum 182 V-Twin Model Airplane Engine, manufactured in England, circa 1980's. L=9", W=10", H=7".

Peter Roffe and Brian Stammer developed the Magnum engines in the early 1980's. They combined two cylinder assemblies from their single-cylinder 91S to make this 90° V-twin 182. The 27 mm bore and 26 mm stroke equal about 15cc per cylinder with a total displacement of almost 30 cc. Magnum engines typically burned methanol on glow ignition, but this model utilizes spark ignition and sports a rare built-in electric starter.

138—Magnum 273 3-Cylinder Radial Model Airplane Engine, manufactured in England, circa 1980's. L=20", W=9", H=9".

The Magnum 91S was a single-cylinder, four-cycle, air-cooled model airplane engine that burned methanol on glow ignition. They adapted three of their 91S cylinder assemblies to a common crankcase to produce this three-cylinder radial 273 A few of these radials were converted to burn methanol on spark ignition by utilizing spark plugs and adding a camshaft driven distributor in back. The distributor, which supports a distributor cap provided by Bruce Satra (Utah) was mounted to a movable plate to provide manual adjustment for spark timing.

149—Olds Stationary Engine, 1/2 scale model built by Everett Kroll, California, 1990's. Castings by Paul Briesch. L=16", W=13", H=14".

Everett machined and fabricated all of the components necessary to complete a running engine. it burns gasoline with a little oil mixed in for upper-end (piston and valve) lubrication. Typical of most stationary engines is that manual lubrication is required on the moving parts before operation, and periodic lubrication.

Olds hopper-cooled (water reservoir around the cylinder) stationary engine first appeared about 1907 and, except for the open hopper, all of the details for these "A" type engines remained much the same. The smaller 2 HP models could be supplied with a small hand truck (cart) for portability while the larger engines required horse drawn trucks. Some of the "A" series engines were air-cooled and featured a cooling fan. Special attention was given to the cooling system—closely spaced fins and a special air shroud forced air completely around the cylinder.

157—Trimble Air-Cooled Prototype Single-Cylinder Engine, designed and built by George Trimble, Arizona, 1958. L=7", W=3", H=5".

George Trimble's first engine is this air-cooled, four-cycle single that burns gasoline on spark ignition. The ventilated crankcase is filled with oil for splash lubrication, but the exposed rockers required manual lubrication before operating the engine.

George attributed its poor performance to his attempt to make his own piston rings. it had poor compression and burned a lot of oil, which led him in pursuit of a mathematical formula for making the "perfect piston ring." the results of his efforts were published as a construction article in Strictly IC magazine entitled "How to Make Piston Rings." This engine served as a test platform through out his developmental trials to produce piston rings that would seat within minutes of starting an engine.

184—TechnoPower 5-Cylinder Radial Prototype Engine, Designed and built by Wally Warner, Illinois, 1983.

This prototype marked the beginning of a new line of 1/4 scale size engine to power large model aircraft. it is about 13" in diameter with a bore of 1.100" and a stroke of 1.00". It was designed to burn methanol on spark ignition and has two shafts extending from the rear gear case. One is for the distributor and the other is intended for a starter.

199—Bandicoot Experimental Model Airplane Engine, by Rich Wiley, Missouri, Date Unknown.

Rich Wiley produced this test engine to determine the performance advantages (or disadvantages) of a highly over-square engine; that is, one with a very short stroke compared to the bore of the engine. It has a bore of 1.160" and a stroke of only .580", yielding a total displacement of .609 cubic inches. The porting arrangement of four transfers (two boost and two exhaust) was chosen in an attempt to shorten the distance the fuel charge needed to travel. The twin rotary valve arrangement was necessary because the crank pin was so close to the centerline of the shaft that it would not allow for a large enough passage hole through the shaft for the fuel. The hole was bored eccentric away from the crank pinto help compensate for this condition. After extensive testing, Rich determined there was not enough advantage to pursue it any further This engine turned its 9-6 propeller up to 14,5000 RPM.

213—Babcock Jr. Gas Powered Micro Rail Mite Racer, designed and built by John D. Ellis, New Jersey, 2009. L=4.5", W=3", H=2".

John Ellis produced this miniature rail racer as a tribute to the late John Babcock, who was one of the most colorful builders and model racers in the San Francisco Bay Area of California. The top and pan are CNC machined from 2024 billet aluminum and mirror polished. The gas tank is 360 brass, the engine mount is naval bronze and the wheels and engine straps are 70075-T6 aluminum. It is powered by a Cox .010 that is bevel geared (3:1 ratio for torque) to a ring gear that is silver brazed to an h-13 form-ground rear axel. The 100% functional rail guides sport four Timken stainless ball bearings.

219—Ferrari V-12 Model Auto Engine, 1/4 scale, built by Bennie Vreeman, Netherlands, 2009. L=12", W=8", H=6".

Jeron Classic Motors began to develop a series of miniature 1/4 scale cars and engines in the mid-1990's. Only a few of the cars were sold before the company closed its doors forever and all remaining inventory was sold at auction. Twelve engines were built from the inventory parts by Bennie Vreeman in the Netherlands. One engine was a running model that burned methanol on glow ignition, while the remaining eleven were built for display only. This engine was one of the non-running models but was converted to a running model in 2009 for the Miniature Engineering Museum. It burns methanol on glow ignition and is equipped with two oil pumps for dry sump lubrication. All six carburetors function and are linked together for smooth operation.

220—Suevia 252 Single-Cylinder Model Airplane Engine, designed and built in W. Germany, 1980's. L=6", W=3.5", H=6". (Courtesy of Dale Jordan.)

This engine is reported to be an efficient glow ignition engine that utilizes Schnurele-scavenge porting. Its displacement is 1.5 cubic inches. It produces 3 HP at 11,000 RPM and swings a 14-7.5 propeller.

221—Anderson Spitfire .65 Model Airplane Engine, built by Marvin Miller (Courtesy of Dale Jordan). Weight: 2 lb.

222—Super Cyclone 60 Model Airplane Engine in original box, reproduced by Larry Jenno, Nevada (Courtesy of Dale Jordan), Weight: 2 lb.

228—Two-Cylinder Vertical Steam Engine, built by Alphonse C. Vassallo, California, 1968. (Courtesy of Cherise Vassallo, Ingrid Vassallo, Andre Vassallo). L=8.5", W=5", H=6". Weight: 4.5 lb.

Stuart Models provided the castings for this model D10 vertical steam engine. It is well suited for stationary and marine work and can achieve speeds of 2000 RPM. Mr. Vassallo machined every part to complete this highly modified version, which incorporates his own custom-designed reversing mechanism. Another personal touch is his use of chrome plating on the fittings, valves, tubing, flanges and other accessory components.

229—Two-Cylinder Flame Licker Engine, built by Alphonse C. Vassallo, California, 1968. (Courtesy of Cherise Vassallo, Ingrid Vassallo, Andre Vassallo). L=12", W=6.5", H=3.5". Weight: 7 lb.

These engines are variously called vacuum, flame-licker or flame-gulper engines and work by drawing hot gasses or a flame into a cylinder to be cooled. Admission of the hot flame into the cylinder is controlled by a valve. There is a power stroke every revolution. On the downward stroke of the piston, the valve is open and flame is drawn into the cylinder. Just before the bottom of the stroke the valve is closed and the resulting drop in pressure draws back the piston for the power stroke. One problem to be found in running these engines is that of back-pressure at the end of the power stroke. it is important to construct the exhaust valve so that it can easily lift and release any back-pressure.

230—Two-Cylinder, Reversible Stirling Cycle Engine, built by Alphonse C. Vassallo, California, 1971. (Courtesy of Cherise Vassallo, Ingrid Vassallo, Andre Vassallo). L=21", W=8", H=7". Weight: 12 lb.

A Stirling engine is a device that converts heat energy into mechanical power by alternating compressing and expanding a fixed quantity of air (or other gas) at different temperatures. Intrigued by the concept, Mr. Vassallo designed and built this horizontal twin inline Stirling engine. It sports custom made burners at the top of the cylinders and his custom-designed reversing mechanism to control the direction of the output shaft. Shortly after completion, Al tested the engine in a model boat a Spreckles Lake in golden Gate Park, San Francisco, CA. The success of this engine led him to design and develop several other Stirling cycle engines.

231—Two-Cylinder Opposed Model Airplane Engine, built by Alphonse C. Vassallo, California, 1985. (Courtesy of Cherise Vassallo, Ingrid Vassallo, Andre Vassallo). L=11", W=10", H=7.7". Weight: 6.5 lb.

This two-cylinder, four-cycle engine is completely machined from steel and aluminum bar stock, including Al's custom-designed carburetor. It has a bore of 1 inch and a stroke of 1 inch and burns methanol on glow ignition. The enclosed rocker arms are lubricated by the fuel/air mixture; hoverer, the gear case in back required grease packing or manual lubrication. Al flew several variations of his airplane engines in numerous scratch-built aircraft he produced.

232—Cylindrical Cam Stirling Engine, built by Alphonse C. Vassallo, California, 1996. (Courtesy of Cherise Vassallo, Ingrid Vassallo, Andre Vassallo). L=23", W=7", H=8". Weight: 17 lb.

The axial engine (also called cam, swashplate or barrel engine) is a type of reciprocating engine that replaces the common crankshaft with a circular plate. The pistons press against the plate in sequence, forcing it to rotate around its center. in Al's engine, the plate has a channel machined around its circumference to capture ball bearings attached to shafts so the reciprocating pistons not only push, but also pull against the cam, forcing it to rotate around its center. The key advantage of the design is that the cylinders are arranged in parallel around the edge of the cam resulting in a very compact cylindrical shaped engine.

Mr. Vassallo was awarded US Patent # 6,701,709 for his "Cylindrical Cam Stirling Engine Drive" in 2004.

233—V-Four Stirling Cycle Engine, built by Alphonse C. Vassallo, California, 1994. (Courtesy of Cherise Vassallo, Ingrid Vassallo, Andre Vassallo). L=13", W=16", H=11". Weight: 20 lb.

Among the numerous Stirling cycle engines Al designed and built is this large V-4 workhorse that he attached to a small generator and water pump. It operates on propane gas that is delivered to special custom-built burners designed to direct as much heat to the heads as possible, then the pump circulates water to cool the cylinders, which increases the power output and efficiency. It isn't known if Al had a purpose for this engine or if he was just experimenting, but he displayed and demonstrated its function at several of the local model engine shows and meetings.

234—Cylindrical Rotary Engine, built by Alphonse C. Vassallo, California, 1973. (Courtesy of Cherise Vassallo, Ingrid Vassallo, Andre Vassallo). L=7", W=5", H=3.5". Weight: 5 lb.

Al experimented with many new "proof-of-concept" engine designs. Internally, this engine resembles a positive-flow (vein type) rotary pump similar in design to a water pump. Al designed a spring-loaded, four-vein rotor, which he placed within a highly modified combustion chamber. Then he carefully positioned the carburetor and exhaust manifold and strategically installed the spark plug for proper ignition The ignition points and adjustable timer assembly are mounted on the back of the engine. Although never completed, it was designed to burn gasoline with oil mixed in for lubrication.

235—5-Cylinder Radial Model Airplane Engine, built by Alphonse C. Vassallo, California, 1982. (Courtesy of Cherise Vassallo, Ingrid Vassallo, Andre Vassallo). L=17", W=13", H=14". Weight: 21 lb.

It took Al about a year to design and build this 5-cylinder radial engine including the carburetor, which customarily incorporates a built-in choke mechanism. It is completely machined from aluminum and steel bar stock and burns methanol with castor oil mixed in for lubrication. The exposed rocker arms require manual lubrication before operation. Unlike typical radial engines, Al designed this one over-square, which means the bore is larger than the length of the stroke, using a 1.25" bore and a 1.00" stroke. Generally, over-square engines are lighter and shorter (smaller in diameter) and develop more power for their compact size.

Challenger V8—Although not part of the museum's collection, Paul Knapp built this Challenger V8. It fires with the flip of the flywheel and runs beautifully. To see video of it being run at a model engineering show in Oregon, CLICK HERE.

http://www.craftsmanshipmuseum.com/KnappCol.htm

www.craftsmanshipmuseum.com/KnappCol.htm