In a message dated 8/16/2005 3:22:35 PM Central Standard Time,
tr3driver@comcast.net writes:
> Interesting that the 'wet' compression reading was less in #4, even though
> the leakdown tester showed less leakage. One explanation for that might be
> that you got just a little bit more oil into #1 than into #4, since the
> extra oil has the effect of raising the compression ratio during the test.
> Adding oil will always raise the reading somewhat, for that reason.
>
I vote for the cam lobes. If the #4 intake valve is closing late the
compression pressure will be lower. But then the readings are not that much
different considering he rounded them off to the nearest 5PSI.
Another possibility is if he did #1 first then the #4 test would be on a
slightly cooler engine leading to less air warming and lower pressures.
Or maybe a cockroach crawled into the #1 cylinder after he oiled it. Could
be a lot of things.
Dave
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