Is this an Exhaust Leak?
 

O-320-A1A EXHAUST PICTURE

Referencing linked picture above...What say ye concerning the rust color on the head near the exhaust flange and around the plug well?

It looks to me like a exhaust leak but isn't the typical white color. The other thing I notice is the flange studs...doesn't look like those nuts have come off in awhile which means the exhaust hasn't been removed for inspection.

Possible crack in the head between the exhaust port and spark plug hole?

Easy enough to test. Pull the plug and do a compression check.
If it is a leak/crack it will show itself instantly.

Typical signs of exhaust leak are a matte, dark black staining/coating. Rust is something different.

What is above the cylinder in that area?

Not necessarily true. If the crack is between the exhaust valve and the exhaust manifold, a compression check will not reveal a crack/leak in that area. We found that this past week on our #2 cylinder on our Warrior. It compression tested at 76lbs, but a cracked cylinder in the exhaust port was found.

Every exhaust leak I've seen showed as a white or light tan coating. If it's black you are too rich at idle.

There's nothing mounted on or above the head that would be causing the discoloration.

The source of those rust-colored deposits has to be steel, so that pretty much narrows down the source. If it were my plane, I would suspect that exhaust gasket first. Good luck breaking that exhaust nut free :eek:

what color is your baffle material?

Good point. I have only had exhaust leaks on my high performance engines and they run much richer than most.

Larry

Not necessarily true. If the crack is between the exhaust valve and the exhaust manifold, a compression check will not reveal a crack/leak in that area. We found that this past week on our #2 cylinder on our Warrior. It compression tested at 76lbs, but a cracked cylinder in the exhaust port was found.


I agree, I was pulling high 60's on my O-360 so technically a pass. But it still didn't feel right when running. So, I sprayed soapy water around the head and sure enough I had bubbles. Pulled the jug and found a crack between the bottom plug and exhaust valve.

If I remember it was black

Exhaust Leak
 

I?ve seen this strange orange color many times before. You have an exhaust leak at a minimum but looking around the sparkplug I suspect you may have a cracked head as well.😕

Well...it doesn't give me a good feeling so the airplane has come off purchase list. Too many other great airplanes to even consider.