Hello!
On our Pitts S1c i discovered a problem which appears to be related to the engine mounts. (lyc o320 A2A) it started when the starting gear on the crankshaft scratched the inside of the cowling front mask during negative g flight at -3g (maybe just a tad more but never above -3.5g). so i figured the rubber mounts needed replacement. the old ones were quite soft and worn out and i was hoping to see a change, but the engine still moves a lot inside the cowling with the new rubbers installed. the tubes which support the engine are not cracked or bent, and when i jack up the engine nothing else moves but the engine . at the crankshaft there is approx. 1 inch movement max. relative to the cowling. is this normal and only the cowling does not fit correctly? from what i hear other people go as far as -4.5 without any problems with the engine biting the cowling...
any hints where to look at? would it make sense to adjust the engine tilt downwards using a washer on the top mounts?
is the engine mount the limiting factor for the negative gs on a pitts?
thanks for your ideas!
Christian
On our Pitts S1c i discovered a problem which appears to be related to the engine mounts. (lyc o320 A2A) it started when the starting gear on the crankshaft scratched the inside of the cowling front mask during negative g flight at -3g (maybe just a tad more but never above -3.5g). so i figured the rubber mounts needed replacement. the old ones were quite soft and worn out and i was hoping to see a change, but the engine still moves a lot inside the cowling with the new rubbers installed. the tubes which support the engine are not cracked or bent, and when i jack up the engine nothing else moves but the engine . at the crankshaft there is approx. 1 inch movement max. relative to the cowling. is this normal and only the cowling does not fit correctly? from what i hear other people go as far as -4.5 without any problems with the engine biting the cowling...
any hints where to look at? would it make sense to adjust the engine tilt downwards using a washer on the top mounts?
is the engine mount the limiting factor for the negative gs on a pitts?
thanks for your ideas!
Christian
