I have had a constant oil leak from my head/cylinder joint, so thought i would take the head off to have a look.
I was using a solid copper gasket, suitably annealed, with a very light film of sealant that I cant remember. Maney standard bore alloy barrels and pistons, skimmed RH4 head with big inlet and exhaust valves.
The performance was good, but the constant slight oil leak was annoying and visually unappealing. retensioning head had zero effect
When the head came off, there was a lot of oil, especially on underside of gasket, pooling in long allen heads that hold barrels down etc.
I have a brand new AN composite gasket, as well as a selection of good copper gaskets I could use.
I believe the oil to mainly come from pushrod tunnels, and when I look as the composite gasket with the (aluminium?) eyelet rings around the bore holes, I am concerned that they could make the problem worse by holding the pressure and thereby reducing the performance on the rest of the mating surfaces, despite that they are crushable to some degree.
As I would like to solve the issue of oil, which gasket should I go with?
I used to have the 3rd fin porosity but after 30 years the Comstock breather valve finally cured that.
There was a lot of very hard carbon deposits on the piston crowns, looked like weld slag, mainly in the valve pockets, which I assumed was from oil getting into the combustion chambers.
I know there are many opinions but i need to choose a course!
TA
Johnny
I was using a solid copper gasket, suitably annealed, with a very light film of sealant that I cant remember. Maney standard bore alloy barrels and pistons, skimmed RH4 head with big inlet and exhaust valves.
The performance was good, but the constant slight oil leak was annoying and visually unappealing. retensioning head had zero effect
When the head came off, there was a lot of oil, especially on underside of gasket, pooling in long allen heads that hold barrels down etc.
I have a brand new AN composite gasket, as well as a selection of good copper gaskets I could use.
I believe the oil to mainly come from pushrod tunnels, and when I look as the composite gasket with the (aluminium?) eyelet rings around the bore holes, I am concerned that they could make the problem worse by holding the pressure and thereby reducing the performance on the rest of the mating surfaces, despite that they are crushable to some degree.
As I would like to solve the issue of oil, which gasket should I go with?
I used to have the 3rd fin porosity but after 30 years the Comstock breather valve finally cured that.
There was a lot of very hard carbon deposits on the piston crowns, looked like weld slag, mainly in the valve pockets, which I assumed was from oil getting into the combustion chambers.
I know there are many opinions but i need to choose a course!
TA
Johnny