Originally Posted by
su27flanker
Hi Guys,
I have an fg-90 in a Phonex Waco and I find the top cylinder gets super hot compared to the bottom cylinders, its to the point where I have to just about idle around the sky as the temps on the top cyl jump to 150 – 160deg not long being in the air. the bottom temps are much lower.
Is this a baffling issue? or the high temp is normal for this motor, I think it would keep climbing if I didn’t back off?
What prop are you using? Baffles are a must for this engine. They should be about 25mm back from the front of the heat sink. This puts the baffles right around the engine center line. Make sure you have plenty of exit air out the back of cowl.
Dummy cowls are not the kind of baffles you need for the engine. I attached the baffles using some L brackets cut from aluminum.
Hope this helps,
jim