[Healeys] Compression test

Michael Salter msalter at precisionsportscar.com
Wed Dec 12 14:38:19 MST 2007

Hi Michael,
The idea of the wet test is to identify whether the leakage is through the
valves or the rings. The fact that there is very little improvement in the
relative compressions would definitely indicate that a valve problem is the
likely cause. 
The advantage of doing a leak down test in this instance is that you may be
able to hear where the leakage is occurring, noise at the exhaust for valve,
noise from the oil filler cap for the rings. 

Michael Salter
100 (1953)
AHX12 (1953)
Bugeye (1961)

-----Original Message-----
From: healeys-bounces+msalter=precisionsportscar.com at autox.team.net
[mailto:healeys-bounces+msalter=precisionsportscar.com at autox.team.net] On
Behalf Of Awgertoo at aol.com
Sent: December 12, 2007 3:13 PM
To: healeys at autox.team.net
Subject: [Healeys] Compression test

This question is related to an MGA engine so if you aren't interested
press DELETE now.
I did a compression test on the MGA engine in my Elva and got the  following

results (reading from cylinders 1-4):
Engine cold :  156-148-137-158
Engine hot:     137-140-125-145
W/squirt of oil: 147-150-133-160
It seems that cylinder #3 is low by about 10-15% across the  board.   But 
does the fact that the oil squirt raised all readings up  proportionally
toward a bad exhaust valve?  Would a leakdown test be  any more significant?
Thanks--Michael Oritt

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