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Re: Low Compression on Spit

To: NA Campiglia <spitdrvr@camalott.com>
Subject: Re: Low Compression on Spit
From: "Michael D. Porter" <mdporter@rt66.com>
Date: Thu, 25 Dec 1997 18:27:52 -0800
Cc: triumphs@Autox.Team.Net
Organization: Barely Enough
References: <3.0.3.32.19971226182046.006a3f98@camalott.com>
NA Campiglia wrote:
> 
> Hello all and happy holidays.
> 
> I was working on my buddies Spit today, he got some goodies for Christmas,
> and we did a compression check.  It wasn't sounding right and we found out
> why, 1&2 cyl are reading 30 and 3&4 are reading 125.  My question is, could
> this be the valves or is it the rings?  It doesn't seem to burning any oil
> and has a new head gasket.

Traditional wisdom says this is the head and/or the head
gasket--pressure is leaking between cylinders 1 and 2. Even if the head
gasket were new, but the head were warped enough to require milling (and
that was not done), there would likely continue to be leakage between
the cylinders. The other possibility is a crack between  

The sure way to determine the cause is to borrow or rent a leakdown
tester. This item maintains regulated air flow into one cylinder at a
time. Lock the engine at #1 TDC, hook it up to #1, and listen for leaks.
If you hear air hissing in #2, guess what? Hook it up to #2 and hear air
hissing in #1, that would confirm it. If you hear air going into the pan
at an accelerated rate, that's air going past the rings, out of the
exhaust port--past the exhaust valve, out of the intake--air getting
past the intake valve. Air bubbles in the coolant, then there's a leaky
head gasket or a crack somewhere into a coolant passage. You get the
picture.

Cheers.

-- 
My other Triumph runs, but....

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