Thanks Chris, Do you know if they are still being manufactured with vacuum defeating holes in the top?
I have Eastern lifters with the holes drilled through the top of the body.
I also have a chronic oil leak on all tins, but especially the exhaust tins (probably because they are the lowest points)
I have changed the tin gaskets three times and the pushrods corks twice, trying to chase down the leak.
But after the first refit of gaskets I am convinced that my gaskets have been vacuum tight each time.
The engine is a 1937 EL but the heads were retrofitted with genuine 38-39 tins back in the day.
The rockers are not touching the tin covers.
The gaskets hold tight and dry for about 20 minutes into a ride, then it looks like the tins overfilled with oil and the oil pushes out past the sealed gasket. The gasket surfaces on the tins have been thoroughly cleaned with Accertone and I have used 3 bond and Airoquip aviation gasket sealer on separate occasions, and each time I let it cure over night before starting.
The engine is new and fully rebuilt and now has 1300 miles on it. The engine is beautifully built, smooth, quiet and starts first kick even after sitting for a couple of months but I am lost with this issue
We installed Eastern because they are the only manufacturer who offers the larger oversize lifters.
Has anyone had this problem with these ventilated Eastern lifters and then welded/closed the holes and seen the problem solved?