[Vlad]

I am in the baffle trimming process right now. Getting ready for plenum layup. Can somebody tell me how much approximately the engine vibrates during start up and shut down? I need to figure out safe distance from upper cowling to the plenum to prevent touching and chafing. Do you guys notice how many feet up and down your engine moves within the cowling?

 

[dhall_polo]

baffling instructions?

The instructions on my -7 baffle kit said about 3/8" - 1/2".

 

[videobobk]

I may be wrong, but it seems to be proportional to the weight of the prop.

Bob Kelly

 

[N941WR]

If you don't have enough room, it will rub and let you know during your test period. There will be black marks from where it is rubbing. Just file it down in those spots and you should be good. Don't let it go too long or it will cut through.

 

[Mel]

I may be wrong, but it seems to be proportional to the weight of the prop.

Bob Kelly

Bob is correct. A heavy prop increases the "shake" quite a bit.

 

[terrykohler]

Once you start flying, be sure to check the clearance of the exhaust pipes to the motor mount (near lower cowl exit). My pipes were making contact, and only a few start/stop cycles managed to inflict some damage to the mount.
Terry, CFI
RV9A N323TP

 

[trib]

Terry,

Were the damages just cosmetic (rubbed the primer off) or did it actually damage the mount somehow?

 

[terrykohler]

Actually hammered flat spots into the mount. Had an inspector look at it and pronounce it still fit. However, if I had allowed it to continue, I'd be looking at a welding project. BTW, my first attempt at realignment resulted in the pipes making contact with the bottom lip of the fuselage (marks on the pipes). I now have over .5 inches of clearance all the way around. This all happened after the prop was dynamically balanced.
Terry, CFI
RV9A N323TP