cylinder to case seal

[Johns]

Having a problem with #1 and 2 cylinder side of motor leaking from the base of cyl to the case at higher rpms.(Above 2,000) Looks more like # 2. I recently had the motor home and cleaned everything, resealed everything with Permatex aviation form a gasket #3 and it still leaks. Not as bad as before but enough to keep me grounded.

Anyone else have this problem? Maybe a different sealer? Ideas? John

[wmbarber]

I have the same problem but mine appears to be the number one cylinder and has occurred with both Permatex and RTV red. Hopefully someone has some suggestions. Otherwise how many have had success with the Permatex verses sucess with RTV?

Pete

[Onex107]

Crazy suggestion. If you have shims under the cylinder you have to seal each one also.

[Johns]

Yes, I have shims and I did seal both sides. That is what so frustrating, I am sure I did it correct. Ready to bring it home and try again.
John

[kmacht]

If it is a new issue have you taken a good look at the crankcase vent? Building up even a slight positive pressure in the case can cause leaks.

Keith

[Area 51%]

Are you sure the leak isn't coming from the hold-down studs?

[Johns]

I am pretty sure they are all blind holes on that side. Correct me if I'm wrong. John

[Area 51%]

The back 2 studs on #1 cylinder go all the way through into the case. PM me your email address and I'll send you a picture.

[lutorm]

Yes, I have shims and I did seal both sides. That is what so frustrating, I am sure I did it correct. Ready to bring it home and try again.
John

On my case, the cylinder stud "case saver" inserts protruded slightly above the cylinder base, so the shim would not lie flat against the base. I had to (very carefully) dremel down the inserts where they run under the shim. It's described, with a picture, here. Are you positive yours don't have the same issue?

[Johns]

Lutorm, I have the engine home and that is on my list of things to check although I did check them already. There has to be something I am overlooking.

Thanks everyone, John