OK, folks. I have another mystery.
I've been finishing the restoration on a J2 for a fellow club member.
Unfortunately, I did not assemble the engine, and the person that did
apparently had no clue on how valves are adjusted on triple-M engines.
Therefore, when the head was assembled, there was insufficient (read NO)
clearance on the intake valve on #4 cylinder and precious little on the
exhaust valve. A compression test showed around 95 pounds on each of
cylinders 1, 2, and 3, and zero on #4.
Hoping to discover it was only the tight valves causing the problem, I
then removed the cam shaft so that all valves should have been closed.
To my surprise, #4 cylinder now showed about 45 pounds. To my further
surprise, #1, 2, and 3 now read between 45 to 50 pounds.
What would cause a normally operating cylinder (with valves opening and
closing properly) to show 95 pounds pressure and that same cylinder to
show 45 pounds with both valves closed?
Please help clear up the fog from my brain and give me a hint of what
I'm missing.
Regards,
Lew Palmer
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