Subject: Leak Down and Compression Numbers
Author: Greg Bender
Date: May 2, 2005, 3:43 PM
Post ID: 1718800840
Okay, the leak-down tester arrived today and I headed out to the garage
right after work. Here is what I found both for compression and
leak-down:
Compression values (taken with the engine fully warmed up the other day
before I destroyed my breather box):
Left: 130
Right: 130
Leak-down values (taken with the engine stone cold. yes, I know they
should be taken with the engine warm, but I don't have a breather box
just yet. I would suspect these values will increase with a warm engine
due to an expansion of materials AND the associated ring gap???):
Left: 5-6%
Right: 5-6%
I could not detect any air escaping from either the intake or the
exhaust on either cylinder. This is in line with what I would suspect
given the head work that I had done. I could not detect any air escaping
from either the base gasket or the head gasket. I did detect air
escaping from the crankcase via the oil fill hole. This indicates
ring/piston/cylinder wear to me.
But, everything I've read indicates that 5-6% leakage is not bad. Am I
misinformed? Do I just need to be patient and re-run the test when I
have my breather box back installed?
Regards,
Greg Bender
1971 Ambassador
2000 Quota
http://www.thisoldtractor.com/gtbender
Florida MGNOC website
http://www.thisoldtractor.com/fl_mgnoc
Minnesota MGNOC website
http://www.thisoldtractor.com/mn_mgnoc