[Healeys] Fwd: compression electrical

john spaur jmsdarch at sbcglobal.net
Tue Oct 18 17:29:51 MDT 2011


Many thanks to all that responded about my compression test. Most 
recommended that I do a leak down test. At it turned out I could not 
get enough juice to turn the engine over for a compression test. It 
is recommended that a leak down test be done on a warm engine but I 
had to do it cold because it was out of the car.

I purchased a US General leak down tester from Harbor Freight but I 
question the accuracy for several reasons. The instructions say 
connect the air, screw the tester into the cylinder and then set the 
tester side of the gauge to zero. This produced a very uniform 
reading of about 2% per cylinder.

Youtube videos show one connecting the air, setting the gauge to zero 
then connecting it to the cylinder to be tested. This generally 
showed a 20% loss per cylinder although a couple were lower and 
higher. I tested the cylinders four times and the readings varied. If 
I throw out the low and the average is:

1-20%, 2-19%, 3-24%, 4-23%, 5-18%, 6-19%

A 1998 compression test right after the head was rebuilt was:

1-140psi, 2-130-135psi, 3-135-140psi, 4-125psi, 5-125-130psi, 6-125-130psi.

On with the work.

John

>Date: Thu, 13 Oct 2011 21:50:40 -0700
>To: healeys at autox.team.net
>From: john spaur <jmsdarch at sbcglobal.net>
>Subject: [Healeys] compression electrical
>
>So... I need to do a compression test.
>John Spaur


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