While perusing old editions
of American Modeler, I came across an advertisement for a plastic model of the Wright Cyclone 9 radial
aircraft engine that was made by Monogram. The ad from the November 1959 edition can be seen to the
A guy in Louisiana sent me an e-mail asking whether I would like to buy a pair of kits that were
in his father's basement. His father was a lifelong modeler and had recently passed away. As you can
see by the photos, the boxes are a bit rough from high humidity, but the plastic parts inside and the
paperwork are all in great condition. Because of openings in the boxes, a couple of the smaller parts
had gotten lost, but I did an inventory of both kits and know that there is one complete kit with 100%
of the parts, and the second has most of the major parts.
Two Monogram Wright Cyclone 9 Radial Engine Kits
The parts groups are also shown. Click the thumbnails for larger versions.
Here is the pamphlet that came with the Wright Cyclone 9 Radial Aircraft Engine
In order to assist the search engines in finding this page for you, I OCRed some of the pertinent
text from the pamphlet:
A FAMOUS ENGINE OF FAMOUS AIRCRAFT
Designed and built by the Wright Aeronautical Division of the Curtiss-Wright Corporation, the Cyclone
'9' is one of the most famous aircraft engines ever produced. Originally introduced in 1931 as model
R1820E, the Cyclone developed 575 horsepower at take-off. Now, after numerous design improvements, the
latest model, the C9HE develops 1525 horsepower with the same 1820 cubic inch displacement.
The Cyclone '9' has been used to power over 35 different airplanes and has flown millions of hours
in both civil and military aircraft. More than 11,500 engines have been operated commercially and approximately
103,- 000 have been delivered to the military services.
The Cyclone is a nine cylinder, single row, radial aircraft engine of 1820 cubic inch displacement.
Originally designed over 25 years ago, it has gone through numerous design changes and engineering refinements
- all accomplished without altering the basic simplicity of the engine. As a result, the Cyclone is
the lightest, most powerful and economical nine cylinder aircraft engine in the world.
Weighing only 1390 pounds and developing 1525 horsepower for take-off, the Cyclone C9HE has a power-to-weight
ratio of less than one pound per horsepower. The crankshaft turns at 2800 revolutions per minute (RPM)
at take-off; 2500 RPM at maximum continuous speed and at 2400 RPM at recommended cruising speed.
This outstanding progress is the result of continuous engineering refinement of a basically sound
design. In 1933 the famous "dynamic damper," which allowed higher crankshaft speeds, was introduced
in the model R1820F Cyclone. Forged steel crankcases were applied to the Cyclone "G" -first air-cooled
radial engine to develop 1000 horsepower, in 1935.
During the War, forged aluminum cylinder heads were adopted for the C9HC model that piled up more
than one million hours of combat action. By 1946, the C9HD had bettered the once "unattainable" one
pound per horsepower ratio. Continued refinements in design have resulted in the current model C9HE,
which combines low weight, high horsepower, economy of operation and ease of maintenance.
In a gasoline engine, the fuel is an explosive mixture of gasoline and air, mixed in the carburetor
and fed into the combustion chambers in the cylinders. This mixture is ignited by a spark from the spark
plug from electrical current supplied by the magneto.
INTAKE STROKE (Down) Intake valve open - exhaust valve closed. Fuel is sucked into the cylinder.
COMPRESSION STROKE (Up) Both valves closed. Fuel is compressed to about one-seventh original Volume.
POWER STROKE (Down) Both valves closed. Spark occurs, fuel burns, forcing piston down.
EXHAUST STROKE (Up) Exhaust valve open-intake valve closed. Rising piston pushes burned gases out
into exhaust system.
The exploded and cut-away drawing above shows the six basic assemblies of the Cyclone '9' engine.
These are explained on the opposite page. A seventh assembly-the exhaust system-is not shown, as the
design of the exhaust varies with the installation of the engine in the aircraft.
The crankcase is the basic shell of the engine, housing the crankshaft, and to which are mounted
the other assemblies. The Cyclone '9' crankcase is machined of a high tensile alloy steel forging and
weighs only 107 pounds. This material was chosen to provide maximum-power-section strength and a rigid
and durable mounting surface for the cylinders. Earlier Cyclone engines used a crankcase of aluminum.
This assembly includes the crankshaft, connecting rods, pistons, cylinders and valves. Cylinder barrels
are deep nitrided steel and fitted with aluminum cooling fins. Cylinder heads are machined of aluminum
forgings with deep cooling fins. The master connecting rod is in No.1 cylinder (at top of engine) with
articulated rods to the other eight pistons. Pistons are steel with nickel plating in the ring areas.
Intake and exhaust valves are sodium-filled and valve sterns are
The supercharger is basically a pump to provide a larger Volume of air-fuel mixture to the combustion
chamber of each cylinder. The Cyclone '9' supercharger has an 11.4 inch diameter impeller, fitted to
the rear section of the crankcase. Behind the supercharger are located the various accessory drives
for starter, magneto, generators, fluid power coupling and oil pumps. All of these units are located
on the supercharger rear cover.
The Cyclone '9' uses two oil pumps-one at the front bottom of the engine beneath the oil sump; the
other at the bottom of the supercharger rear cover. The front pump is used to scavenge oil from the
lower ten rocker boxes, which are inter-connected by drain tubes. This feature eliminates
hydraulicing and prevents
oil-throwing and smoking when the engine is started, Oil used in the Cyclone '9' is grade 100. Operating
oil temperature is J85°F with a maximum of 220°F.
To provide better ignition shielding for radio and to improve high altitude performance, the Cyclone
'9' is equipped with a low-tension ignition system. The ignition harness is located on the front of
the engine and carries only low-tension current. High tension coils are located on the cylinder heads
with only short leads to spark plugs. Individual coils (in dual coil assemblies) for each spark plug
increase engine reliability. The dual magneto is mounted on the supercharger rear cover.
The Cyclone '9' is noted for its low rate of fuel consumption. This is due to the high Volumetric
efficiency of the large cylinders, low friction loss and better fuel distribution of the single-row
cylinder arrangement. Fuel is fed to the carburetor from the separately mounted tanks by the fuel pump.
It is mixed with air and vaporized in the carburetor. The supercharger then pumps the fuel-air mixture
to the individual cylinders through the large, curving intake pipes at the rear of each cylinder.
The Monogram model of the Wright Cyclone C9HE Aircraft Engine has been developed from original drawings
supplied by the Curtiss-Wright Corporation.
All major details and features of the actual engine are included and are accurately scaled at one
inch to one foot.
Airplanes that used the Wright Cyclone C9HE:
Grumman S2F Chase C-122 Douglas Super DC3 Northrop C-125 Piasecki H-21
Douglas R4D-8 Douglas DC4 Curtiss SC-2 Ryan FR2 Grumman SA-16
No. Amer. SN2J-l Douglas SBD-6 Eastern FM-2 Grumman F4F Curtiss SC-l
Boeing Stratoliner Lockheed Hudson Vultee V-11GB Martin 166
Lockheed lodestar Boeing B-17 Douglas SBD-5 Curtiss Hawk 75A
Douglas DC3 Curtiss A-18 Douglas 8-18 Martin B-l0B Martin 156
Consolidated P2Y3 Curtiss Hawk 75 Grumman J2F
Douglas DC2 Curtiss Condor Martin B907
Curtiss A-12 Bellanca Air-Cruiser
Martin 124/125 Consolidated P2Yl Bellanca Airbus Curtiss 02C2 Fokker F-7