In a message dated 7/30/99 7:37:10 PM Pacific Daylight Time,
cupola2@worldnet.att.net writes:
<< Dear Group,
Took my '54 3100 in for a compression and leak
down test today, but I'm unsure what it all
means. Here are the fugures they gave me.
Comprssion/PSI Leak Down % Hot 8K
#1 130 40% rings
#2 125 50% rings
#3 105 50% valves
#4 85 70% equally
#5 120 15% valves
#6 125 20% equally
Of course, they would have liked to have kept my
truck. There is no smoke coming from the tailpipe
and I'm no using any oil that I can tell.
Sometimes, when I start her, I get a funky, sweet
smell that goes away after a few minutes. Other
than that, I like driving my old truck.
What do all these figures mean?
John 54 3100 235 six >>
I've never taken a motor to a shop for s leak down test, but I have done
compressioon test's at home before.
The #4 cylinder looks like a poor exhaust valve seat (poorer than the rest)
and if you're runnning a stock can, I'd also say that all the valve are not
seating well. Last time I looked at my Motors Manual, I *think* I recall
140psi as low end of the compression, but i could be wrong, but you may
benefit from a valve job.
The sweet smell you get on startup could be antifreeze from a partially bad
head gasket seal between #3 and #4 (two low adjacent cylinders usually
indicates head gasket).
Just my thoughts.
Mike
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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