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Re: Leak Down Tester

To: "Joe Timney" <joetimney@dol.net>
Subject: Re: Leak Down Tester
From: "Bill Bennett" <benettw@earthlink.net>
Date: Mon, 28 Aug 2000 20:32:02 -0400
Joe help me out here I kinda remember seeing someone who ran a Top
Alcohol Funny Car use a leak down tester on his fuel injector system.
What was this for and what was he doing?
Bill Bennett
----- Original Message -----
From: "Joe Timney" <joetimney@dol.net>
To: <V4GR@aol.com>
Cc: <BICWIG@aol.com>; <kturk@ala.net>; <land-speed@autox.team.net>
Sent: Monday, August 28, 2000 2:38 PM
Subject: Re: Leak Down Tester


> What you are looking for is the delta between the two gauges.
Setting the first
> gauge at 100 psi allows you to simply read the second gauge as a
percent.
> Example, If the first gauge reads 100 # and the second gauge reads
96 #, then
> the leakdown is 4 %. If you only have say 80 lbs. of air from your
compressor,
> you will have to do some math to arrive at a percentage of loss. I
have found
> that a motor with gap-less rings will show 0 to 1 % leakdown if in
good working
> order. 4 to 6 % is not too bad. The motor needs work if you see over
that. I
> have tested motors with the piston in various postions in the bore
looking for
> scarring  or bore scratches. I have had a fuel motor on more than
one occasion
> show good on the leakdown but the piston was melted down around the
rings.
>
> joe
>
> V4GR@aol.com wrote:
>
> > Keith; I don't know why but when I was going to A&P school we
learned to set
> > the gages at 80 lbs. Then we compared the reading on the
downstream gage
> > after opening the air valve. I seem to remember 20% for a worn
cylinder cold
> > was acceptable. More than that was not. Race motors should be much
tighter.
> > After the first few years at the airline we put away our leakdown
testers.
> > Couldn't get them to read correctly on a JT3.  Rich
>
>
>



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