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Re: Compression test how to

To: triumphs@autox.team.net
Subject: Re: Compression test how to
From: d spence <dkspence@telus.net>
Date: Mon, 15 Aug 2005 21:06:54 -0600
Joe
It's time to stop and listen.

What Randall said was absolutely correct. You do a first check on a 
cold dry engine as in, the oil has drained down to the pan. Turn the 
engine over at least three revolutions for each cylinder. If you have a 
low cylinder (or all of them for that matter) you then squirt in some 
oil and repeat the test one cylinder at a time. If there is an increase 
in compression pressure on the second (wet) test you can be assured 
that the rings are failing as the oil will act as a seal of sorts in 
blocking air from leaking past them. If there is no increase in 
pressure you can be very sure the rings are not the major culprit here 
and a burnt valve is.

This is common wisdom  amongst mechanics pro and amateur alike and not 
a Randall rant.
On Monday, August 15, 2005, at 06:27 PM, Triumphs@Autox.team.net daily 
digest wrote:

> Of course you do!  Don't you always?  Notice I said to do it if the
> engine has set for any length of time.  If the engine has been running,
> it should already have a coating of oil on the cylinder walls.  But if
> the walls are dry, the oil will set the cylinders to a condition that
> simulates an engine that has been running.  While it might mask leaking
> rings, not doing it will provide readings that are not under operating
> conditions and therefore questionable.  If you want be sure of the
> readings, repeat them several times and see if the readings go down 
> over
> the range of test cycles.  If they do go down, that would indicate that
> the rings are not properly sealing.  But they might go down and still 
> be
> within operating tolerances.
>
> Joe




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