I had my heads ported last year and have had issues with oil leaking down the side of the exhaust valves, either that or between head and valve guide. It then tracks along the roof of the exhaust port and out through the studs that hold the exhaust manifold on and through the exhaust manifold gasket as well as being burned off with whatever goes into the manifold
I replaced new stem seals first thinking it was them but no change, then the heads came off again and I had the valve guides changed and valves checked for tolerance which was all good. While it was in the shop the guy tested for leakage from the top down ie past the stem seal and nothing got past. It is noticeable on both banks and on all 6 ports. I wonder if the porting was a bit to intense where the valve seats or does this sound like a crack.
Any ideas ?
I replaced new stem seals first thinking it was them but no change, then the heads came off again and I had the valve guides changed and valves checked for tolerance which was all good. While it was in the shop the guy tested for leakage from the top down ie past the stem seal and nothing got past. It is noticeable on both banks and on all 6 ports. I wonder if the porting was a bit to intense where the valve seats or does this sound like a crack.
Any ideas ?