What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Intake Gasket vs Exhaust Gasket

VF84Sluggo

Well Known Member
Perusing threads about these gaskets, I'm wondering why an exhaust gasket can't/shouldn't be used on the intake side. Seems that if it can handle the heat of exhaust gasses, the 'cold' side would be a piece of cake.

What is it about an exhaust gasket that makes it unsuitable as an intake gasket?
 
Perusing threads about these gaskets, I'm wondering why an exhaust gasket can't/shouldn't be used on the intake side. Seems that if it can handle the heat of exhaust gasses, the 'cold' side would be a piece of cake.

What is it about an exhaust gasket that makes it unsuitable as an intake gasket?

Expensive, heavy, thicker, hard (won't seal well enough at idle) and . . . . that should be enough.

The exhaust gasket is just not designed for this purpose.

Ross (SDS) has the best design for an intake gasket I have ever seen - it is very well engineered and typical for SDS, a beautiful part.
 
Last edited:
Perusing threads about these gaskets, I'm wondering why an exhaust gasket can't/shouldn't be used on the intake side. Seems that if it can handle the heat of exhaust gasses, the 'cold' side would be a piece of cake.

What is it about an exhaust gasket that makes it unsuitable as an intake gasket?

The exhaust gasket needs a lot of crush force to seal. The 1/4" steel flange on the exh can handle this, but the thin aluminum intake flange cannot. Suggest you stick with recommended gaskets. Heat is not what is causing the intake gaskets to leak IMHO.
 
Thanks for the good info.

And to be clear, I wasn't planning on using an exhaust gasket on the intake side. Just curious, that's all. Part of the "education" thing here ;)
 
Exhaust Gasket

Perusing threads about these gaskets, I'm wondering why an exhaust gasket can't/shouldn't be used on the intake side. Seems that if it can handle the heat of exhaust gasses, the 'cold' side would be a piece of cake.

What is it about an exhaust gasket that makes it unsuitable as an intake gasket?

Yes, they are the same size, so It depends on the type of gasket. The "No Blow" type wouldn’t seal properly. But what exhaust gaskets did we use before "No Blow" type? These were layered copper, asbestos, copper gaskets, which, with a little High Temp RTV (red) makes a perfect intake seal! I've been using them for over 1500 Hr with no leaks!
The problem is the are not readily available anymore. The best place to find them is at an aviation flee market event....
 
how often should they be replaced?

Only when there are signs of leakage, or when disconnected?
 
77611 Exhaust Gaskets on Intake Flange

I suggest reviewing this old thread: https://vansairforce.net/community/showthread.php?t=120750

I just installed two # 77611 exhaust gaskets on my leaking number 1 and 2 cylinders in my IO-360 M1B. The first test flight showed that the telltale drop in EGT at low manifold pressure and 1700 rpm indicating a leak disappeared.

The gaskets I used were spares delivered with my engine in 2008 and appeared to be bimetallic.

Robert Cowan
RV-7A, 700 hrs.
 
Back
Top