[Healeys] Fwd: compression electrical

[Michael Oritt]

John--

I am not clear on the "setting it to zero" part.  I set the first guage
measuring input pressure to 100 psi simply to give an easy frame of
reference, then crack open the valve for the other guage and when the
cylinder is at TDC with both intake and exhaust valves closed get the
percentage reading.

Judging by your readings of 18% to 24% you are iin for a valve job at the
very least, maybe more.  Perhaps you want to recheck your method and yes it
is best to do this with a warm engine.

Best--Michael Oritt

On Tue, Oct 18, 2011 at 7:29 PM, john spaur <jmsdarch at sbcglobal.net> wrote:

> 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
>>
> ______________________________**_________________
> Healeys at autox.team.net
> Donate: http://www.team.net/donate.**html<http://www.team.net/donate.html>
> Suggested annual donation  $12.75
> Archive: http://www.team.net/archive
> Forums: http://www.team.net/forums
> Unsubscribe/Manage: http://autox.team.net/mailman/**
> options/healeys/michael.oritt@**gmail.com<http://autox.team.net/mailman/options/healeys/michael.oritt@gmail.com>