4* Engine question
 

Hi Folks, Long Time lurker, in-frequent poster...

My dad has a 4*40 that he's flown the past two seasons, the first with an OS .40 SF 2-stroke and the second with a Saito .52 4-stroke. with the 2-stroke the roll rate was pretty equal left-to-right... once the 4 stroke was swaped in, the roll rate increased one direction, and decreased in the other. ie. it rolls left faster than it rolls right (I think, maybe vice-versa).. Is this a result of the extra torque from the 4 stroke to the 2 stroke? AFAIK the prop is the same (11x6, but i could be wrong)...

Any insight would be great!

Thanks

RE: 4* Engine question
 

Yes its the difference in engine torque.

I would expect he used a 10X6 or 11X5 with the .40 and the 11X6 or 12X5 with the .52 4-stroke. 11X6 is a bit much for a .40 2-stroke to be swinging (even the O.S. SF, which I think is a better engine than the FX.)