Hi Bob,
Thanks for your thoughts. I user 90w gear oil, so it was pretty thick.
However, my oil can has a long, flexible hose, so I was able to insert it
through the plug hole to the back of the cylinder (with the piston part way
down the bore). This seemed to do the trick anyway.
You provided me with some useful information though - I was wondering how
much improvement I could expect to see from a cylinder with 'good' rings by
doing this test. As I mentioned, I saw a 10psi increase on a 3/4 warm
engine, but I figured this could be due to the oil providing a better seal
anyway. You mentioned that you saw a 60psi increase on a bad cylinder once.
The compressions on all 8 cylinders are within about 89% of each other from
high to low - I've read that you only need to worry if the spread is less
than 75%.
The shop did listen, and heard some leakage from inlet and exhaust, and a
little from the crankcase. However, I suspect that my head gaskets may not
be sealing perfectly anyway, I get a little bit of oil weeping out of the
cylinder head to block joint after a hard run. I know that Rover type
engines fitted with the tin style head gaskets tend to leak into the valley
between the cylinders. If I do a head swap I'll use the newer composite type
gaskets.
Simon
|