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Subject:Re: Compression pressure figures?
From:Carrington, Tom
Date:Wed, 15 Mar 2000 09:15:40 -0500

Step 1. Go get a mechanic that doesn't "rush" even simple things like a
compression check. I'd hate to see how his "rushed" engine rebuilds turn
out!

The low pressure (75psi) on one cylinder is a problem. The oil being washed
off the bores is BS in my opinion. Gasoline will do a decent job of sealing
up the rings. aybe not as well as oil, but it will still inflate a
compression reading.

When I check out an engine, I'm not really interested in the exact
compression figures but rather how close they are to each other. Factors
like cranking speed, compression gauge inaccuracies, etc can give low or
high readings. But they should be consistent on all 4 cylinders. If all the
cylinders were within 10-15lbs of each other, I would be happy. But the one
in your case is 30 lbs !!!!! lower than the highest.

TomC
tcarrington@relitech.com
http://www.relitech.com/tomc
http://volksweb.relitech.com
85 Vanagon Crew Cab
82 Westy diesel=>gas conversion
65 Notchback

> -----Original Message-----
> From: steve delasalle [SMTP:sdelasal@YAHOO.COM]
> Sent: Wednesday, March 15, 2000 8:31 AM
> To:   vanagon@GERRY.VANAGON.COM
> Subject:      Compression pressure figures?
>
> I think I know the answer here but I'll ask the
> 'collective'.. this 85 bus, water cooled) has
> compression pressure of 105, 90, 100, 75 PSI. mechanic
>
> doing the test says it was rushed - didn't disconnect
> fuel pump and put low pressure down to oil being
> washed off of bores - the mechanic says engine runs
> good and says in his opinion spec's in book are too
> high as he has never seen engien with those figures!
>
> So, it is reasonable to expect engine to have
> compression figures above service limit of 116 PSI and
> preferably within range of 145-190PSI?
>
> Steve
>
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