I had some more time on Saturday to finish compression and leak down test on
Bugsy's spare engine.
I think I can safely conclude that if I pump 100 PSI into cylinder #2 while
engine is at TDC on the compression stroke, and I not only hear but feel
compressed air coming out around rocker arms, chances are I've got either a bad
valve or at least bad valve seals. No air coming out of dipstick which says
something good for the rings on this cylinder. I also noticed slight air
pressure coming out of plug hole for #4 cylinder which would be 180 degrees off
from #2. Assuming carbs were closed, this would also reinforce the threory of
burned valve or severely worn valve guides would it not? Engine I'm told was
consuming oil at a rate of a Qt. every 100 miles.
#4 exhibits the same symptoms although not to the same extent as #2. #1 & #3
cylinders are good to go. Time to pop the head and get a valve job done and see
what the cylinder walls look like before proceeding any further on making a
decision on rings.
#1 Comp. 130 lbs Leak Down 90 lbs
#2 Comp. 65 lbs Leak Down 70 lbs Interesting that Leak down was
higher # than compression # but no air coming out of dipstick. Slight air
pressure on sparkplug in #4. Fairly major air leak can be felt around valve
train
#3 Comp 120 lbs. Leak Down 95 lbs
#4 Comp 85 lbs Leak Down 80 lbs Can feel air leak around valve
train, not as much as #2 but still there. This was only cylinder that could
feel air pressure coming from dipstick, very slight but there. Major air
pressue coming out of plug hole in #2.
Diagnosis - Bad Valves in #2 & #4. Time to take care of that before engine
goes back in Bugsy. In the meantime, the old 1098 chugs on. I'll be curious to
see if others come to the same conclusion on test results as I do. TIA for any
opinions on this one.
Jim Gruber
Bugsy '68 Sprite (future Bugeye in disguise)
Cincinnati, OH
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