The results of my leak down test are in and I must say it do not
prove all that much to me. What I did was remove the valve rocker
arm so that all of the valves would be shut. I then proceeded to
charge each cylinder with air. What I found is the following. I could
no find any air leaking (i.e. hearing a hiss) from the valves. Both
the tail pipe and the carb were silent. For the two cylinders (1 & 4)
with good compression I could not detect any leaks into the crank case.
Cylinders 2 & 3, the ones with the low compression leaked quite a bit
of air into the crank case. I could detect air movement with my fingers
at both the dipstick hole and in the valve galleys. I could not hear
any leakage between adjacent cylinders.
Overall this test told me no more than what I knew before. I still suspect
a blown head gasket. I will confirm this when I pull the head. I did not
measure how quickly the air leaked out. That may have provided more useful
information. Of course there is the always the chance that my untrained
ear
missed some leakage or that I missed some other thing that a more
experienced
mechanic may have detected.
I would have to say while I did not find out any more information, my
attempt
at a leak down test was not a waste of time. Thanks to all the lister for
their
input.
Bill Gilroy
77 Midget
wmgilroy@lucent.com
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