Vintage Cox Engine .049 - .051 - .09

.049 and .051 perform nearly the same. The idea is to allow 1 model to compete in 2 classes with a simple engine change. The 1/2A to A split is .050. This scheme is used in larger engines too, several different brands.

If performance was not effectively the same, and the engine weight not identical this would not have been an effective setup.

The numbers specify displacement in cubic inches. (CI)

Phil

Ian,
thank you very much for this address, is very interesting.

Phil,
thank you for this informations, i understand very well the differences.

Regards
Giuseppe - Italy

jorigger wrote:Good morning at all.
Please, i want know the differences of this sizes Cox Engines: .049 - .051  and .09 -

Thanks and Regards
Giuseppe - Italy

Guiseppe,
Did you get the answers you needed?
Appearance wise, the Cox .051's have a groove on the lower part of the piston for easy identification. The .049 piston fits only the .049 cylinder and the .051 piston fits only the .051 cylinder. There were cosmetic differences like plastic parts colors also. For instance the Tee Dee .049 used a black plastic carb body whereas the .051 used a red one. That is until the last ones went out the door with both using the red body to use up existing parts. Use the groove to verify.
Performance wise, as mentioned, they are the same so one can use the same FF plane in two classes without having to make trim adjustments.
Not sure what you want to know about the .09. The TD .09 is extremely powerful for its size. Runs well.

George

gcb wrote:

jorigger wrote:Good morning at all.
Please, i want know the differences of this sizes Cox Engines: .049 - .051  and .09 -

Thanks and Regards
Giuseppe - Italy

Guiseppe,
Did you get the answers you needed?
Appearance wise, the Cox .051's have a groove on the lower part of the piston for easy identification. The .049 piston fits only the .049 cylinder and the .051 piston fits only the .051 cylinder. There were cosmetic differences like plastic parts colors also. For instance the Tee Dee .049 used a black plastic carb body whereas the .051 used a red one. That is until the last ones went out the door with both using the red body to use up existing parts. Use the groove to verify.
Performance wise, as mentioned, they are the same so one can use the same FF plane in two classes without having to make trim adjustments.
Not sure what you want to know about the .09. The TD .09 is extremely powerful for its size. Runs well.

George

Hi George,
yes i have some answers, but also this you answer is very importan for me, and i want send one special 'thank you very much'.
I have understand very well this you explanations, is very clear.

Best Regards
Giuseppe - Italy