The Cox engines are internal combustion engines used in the model . LM Cox Manufacturing Co., Inc. was founded in 1945 to be resold in 1996 in Estes, which will cease production in 2009. When they stopped producing their engines, the remaining parts stock was resold to a buyer private Canadian, and starts producing parts again, Cox International.
For more than half a century, they propelled boats and cars, but the area in which they were most used is that of model aircraft , especially in free flight and circular flight. Millions of these engines have been produced and sold worldwide, and have become and remain the world’s most popular Class 1 / 2A .049 (0.8cc) motors. Even if the production of engines has stopped recently, they continue to be sold in abundance, sometimes still in new condition [ref. necessary] .
Most of the engines built Cox in this business are engines of 0,049 cubic inches, or 0.8 cm 3 . These are 2-stroke engines, using a filament plug to ignite the air / fuel mixture in the cylinder (for more information, refer to the Two-Cycle Cycle page ). The fuel intake is controlled by a needle, and is sent into the cylinder via a non-return valve (also called hip) or a rotary valve.
The fuel used is a more explosive mixture than conventional gasoline, and generally consists of methanol (60 to 70%), castor oil (20%), and nitromethane (10 to 40%).
The first Cox engines
- 045 O-Forty-Five (1949) :
Even though it was not completely produced by Leroy Cox, it was he who supplied most of the pieces and who designed it. It served as a “pack” that was added to cars to propel them. It was a big step forward for his time, as this engine included gearboxes, a tank, a flywheel and a silencer, all in one pack all-in-one.
- 1952 Space Bug :
The Space Bug was the first engine built entirely by Cox. It was designed for circular flying and was sold for $ 6.95 , and included a metal tank at the back, operating on the principle of the check valve.
- Babe Bee 1956 049 ( 0.8 cm ³) :
The Babe Bee is the first Cox engine to have an extrusion- shaped casing (a less expensive process than the old crankcase manufacturing technique, which used a cast aluminum housing). It includes a 5 cm 3 tank and has been sold with thousands of RTF kits worldwide, and remains Cox’s best-known engine.
- 1957 Pee Wee .020 ( 0.33 cm ³) :
With the huge success of the Babe Bee, Leroy Cox decides to start building an engine that is two times smaller than the Babe Bee: the Pee Wee .020. It keeps exactly the same construction as its big brother, and always uses the principle of the check valve.
- 1958 Golden Bee :
The Golden Bee is actually a Bee Babe whose tank has been enlarged (8 cm 3 capacity ), and is colored in gold. The hoses in the tank have been rearranged for aerobatic aircraft to be fueled regardless of orientation. The following versions had modified transfer channels in order to have greater power.
- 1996 Venom :
The Venom is an engine designed for high performance, using a balanced and lightened crankshaft. The piston was designed as the Tee Dee (slightly tapered cylinder). The problem was that the engine produced at the chain was different from the prototype, and the piston was too light, which could cause, at high speed, the detachment of the top of the piston. Only 1000 of these engines have been manufactured, making them quite rare (price going to more than 300 dollars in new condition).
The Tee Dees
- 1961 Tee Dee 049 :
A Cox Tee Dee .049 and .051 side by side
This engine is probably the best Cox engine. This engine was “THE” engine for competitions for many years. It was developed by Bill Atwood, specifically engaged to develop the range of Tee Dee. It has a modified cylinder (slightly conical shape, to ensure a better seal), two additional transfer channels on each side. The crankshaft is balanced precisely to ensure better performance.
- 1961 Tee Dee 051 :
The Tee Dee .051 is just an adapted version of the .049 to be used in class “A”. It is physically the same as the .049, only the bore is different.
- 1994 Tee Dee .051 RC :
A Cox Tee Dee .051 RC
This version of the Tee Dee was specifically designed for RC flight, so it included an RC carburetor and a silencer. Because of the silencer, the Tee Dee .051 RC did not include sub-induction. Only 2000 engines were produced, making it the second most sought-after engine after Venom.
The Tee Dees will be available in several other displacement, from 0.010 to 0.15 cubic inches.
The mechanics of Cox engines
Cylinders and pistons
There were a lot of different types of cylinders, with 3 different wall thicknesses. They were all interchangeable, which was a problem when buying used engines. The first engines had a relatively thin wall, which turned out to be a disadvantage, as they folded quite easily during a crash or when dismounted. The following generations have been expanded only at the level of the exhaust, and finally the last generations have been widened over the entire length, allowing the installation of a ring of control of gases.
This image above allows to see the different sections of the cylinders, and the transfer ports.
The # 1 is a Tee Dee cylinder with two additional ports on each side of the first transfer channel.
No. 2 is a cylinder with a grooved exhaust, thus reducing the risk of burns, and with a thicker wall.
No. 3 is a cylinder of Black Widow, with the walls of the cylinders enlarged than the exhaust ports.
The No. 4 is a pre-1955 cylinder with a thin wall, used in Space Bug, Space Bug Jr, Thermal Hopper and Strato Bug. Note the thread diameter of the candle which is smaller than the newer models.
Five types of candles were produced for Cox .049 engines. These candles also served as a bolt, they covered the entire top of the cylinder. Therefore, when the candle was worn, it was necessary to replace the whole breech.
N ° 1: Standard candle, before 1955. Low compression, with a hemispherical shape, smaller thread than the following engines. This candle has only been used on Space Bug, Thermal Hopper, Space Bug Jnr and Strato Bug.
No. 2: Standard candle, after 1955. Low compression, also with a hemispherical shape, with a larger thread. It was used on all the engines until its replacement in 1980 by the model n ° 325.
N ° 3: Standard candle. Low compression, hemispherical shape. Used on all engines except Tee Dee, Killer Bee, Venom, QZ and Texaco. This candle replaced the model n ° 302-1 in 1980.
No. 4: High compression candle, trumpet shaped, with 2 cooling fins. Used only on Tee Dee, Killer Bee, QZ and Venom.
No. 5: Texaco candle. Low compression, hemispherical shape. Only for Cox Texaco, it allowed a better cooling with its 5 fins, which allowed this engine to have a better power.
However, these candles were often considered too expensive, and some then obtained unofficial candles, manufactured by other manufacturers. Still others modified their candles squarely to fit a thread and screw a standard candle.
Davis Diesel conversion kits
These kits can convert these engines into diesel, so as not to be dependent on candles considered too expensive. It is a cylinder head that is screwed in place of the candle, and whose compression ratio can be adjusted via a screw  [ archive ] . Since diesel has a higher compression than “glow”, it is often necessary to change the crankshaft for a reinforced version. Davis conversion heads can be used on Pee Wee .020, Tee Dee and Medallion .049 / .051, and all .049 check valve motors.
These carburetors, developed in Quebec, were equipped with RC settings. Marketed in 1978, they were available in Tee Dee and other non-return valve versions. Unfortunately, they have hardly met with any success and have quickly disappeared, because of their dubious reliability.
The RTF planes of Cox
This table lists the main aircraft sold by LM Cox Manufacturing. It is still in English, but in translation
|1953||TD1||400||Space Bug .049||Cox’s first RTF|
|1954||TD3||600||Space Bug Jnr .049|
|1956||TD4 Trainer||5100||Babe Bee .049|
|1957||Super Cub 105||5200||Babe Bee .049||Replaced by the Super Cub 150|
|1958||Lil Stinker||5300||Pee Wee .020||First aircraft powered by a 020 engine|
|1958||Super Saber||5400||Pee Wee 0.020|
|1959||P40 Warhawk||5500||350-1 Super Bee .049||Babe bee with double transfer channel|
|1960||Commanche||5600||0.15 Sportsman||2.5 cm motor 3|
|1960||PT-19 Trainer||5700||Babe Bee .049||Other versions have been released: 5710, 5761, 5900 and 6300|
|1960||Curtiss Pusher (Kit)||5800||350-2 Babe Bee .049||First RTF kit|
|1961||Airplane Shinn 2150-A||6200||190 Production Engine|
|1962||Ju87D Stuka||6400||190-1 Production Engine|
|1962||P51B Bendix Trophy Racer||6600||190-2 Production Engine|
|1962||Super Cub 150||5200||190-4 Production Engine||Update Super Cub 105|
|1963||Curtiss SB2C Helldiver||7000||190-3 Production Engine|
|1963||L-4 Grasshopper||7200||190-4 Production Engine|
|1963||Spook||7420||290 Spook Engine||Flying wing (in kit)|
|1963||P51B Mustang aircraft||7600||190-2 Production Engine|
|1964||P40 Kittyhawk||8400||Super Bee .049||RAF version of the Warhawk P40|
|1964||Spitfire||7800||350-6 Silver Bee .049||First version of the Spitfire replaced in 1966|
|1965||Curtiss A-25 Bomber||7100||190-3 Production Engine|
|1966||RAF Spitfire||7800||Silver Bee .049||2 E version with the colors of the RAF|
|1966||T-28||7900||290 Production Engine|
|1966||QZ PT-19 Trainer||5900||QZ .049||PT-19 with a QZ engine|
|1967||AD-6 Skyraider||9700||190-6 Production Engine|
|1968||F2G-1 Corsair||7500||290 Production Engine||# 7562 with flying accessories|
|1968||Pitts Special||8200||Pee Wee 020||Variation of the lil Stinker|
|1969||Thompson Trophy Corsair 27||2900||290 Production Engine|
|1969||Red Baron||5300||Pee Wee 020||Also released as “Red Knight”|
|1969||Mini Stunt Biplane||7300||Pee Wee 020||Another version of the lil Stinker|
|1969||Ryan ST-3 Super Sport||6200 (& 6200-80)||Pee Wee 020||also available in trottled version 6200-80|
|1969||Ryan PT Army Trainer||6300 (& 6300-80)||Pee Wee 020||same as 6200 & 6200-80 but in Army colors|
|1970||Corsair II||3900||290 Production Engine||Chrome plated – left hand prop.|
|1971||Acro Cub||4600||190-4 Production Engine||variant of the Super Cub|
|1971||rivets||6800||350-9 Production Engine||popular design sought by collectors|
|1971||P51D Miss America Mustang||6900||190-7 Production Engine||Stars and stripes color scheme|
|1971||P51D Mustang||7600||190-6 Production Engine||bubble canopy|
|1972||Sopwith Camel||8000||191-0 Production Engine|
|1972||Fokker DVII||8100||191-2 Production Engine|
|1972||Fokker DR1 Triplane||8300||191-0 Production Engine|
|1973||Super Sport Trainer||8600||191-3 Production Engine||Pink aerobatics trainer|
|1973||Bushmaster||8700||190-4 Production Engine||convertible with floats and skis|
|1974||Super Stunter||5400||191-7 Production Engine||First design with foam wings|
|1975||Cessna 150||4000||191-8 Production Engine||Sure Flyer with autopilot|
|1975||Piper Comanche||4100||191-8 Production Engine||Sure Flyer with autopilot|
|1976||Skymaster||4200||191-8 Production Engine||Sure Flyer with autopilot|
|1976||P-39 Airacobra||4300||191-8 Production Engine||Sure Flyer with autopilot|
|1976||Sky-Copter||7100||Pee Wee 020||First helicopter (free flight)|
|1976||Crusader Stunt Trainer||9000||191-9 Production Engine||Foam wing stunter|