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Discussion Starter · #1 ·
As always I started to fix one problem...then ran into another issue.
The first was to lower the under hood temps. And a camshaft swap.
First off I wanted to know if the engine was in good shape after a few years of abuse.
So I brought home my leakdown tester.
Heres a bad pic of the basic setup.

After setting the regulator to zero I noticed the other gauge wasn't right on 100 psi.


So how far off is the final reading?
 

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I getting ready to do this test to the GT, :aargh4: :cussing: does the engine have to be up to temp ? Or can I get an accurate reading without ?? Thanks
 

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9/10 times I'll run this test with the engine cold.
I hate to get my finger's burnt :)

This is dealing percentages with the cylinder pressure only at 100 psi.
With the engine running the pressure is much higher and will expand the rings more.

Be sure to back off on the valve lash tho
 

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9/10 times I'll run this test with the engine cold.
I hate to get my pinger's burnt :)

This is dealing percentages with the cylinder pressure only at 100 psi.
With the engine running the pressure is much higher and will expand the rings more.

Be sure to back off on the valve lash tho
Wrench, wasn't sure if it would make a big difference in the readings, so it might allow more air past the rings when cool then, that's what I thought. I guess if you wanted to loosen all the rockers, which then would cause the valves to close, you could do the test without rotating the engine. I have already adjusted the valves when running, then did a compression test, now this, Thanks
George, Harbor Freight / US General :haha: Chinese made, :bs2: ,has them for $ 39.00
 

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Thanks. I got the 72 GT running.:haha: I need to do compression test, tuneup, oil ect. Surprised it started right up after a cold winter.
 

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Discussion Starter · #11 · (Edited)
... What Wikipedia has to say about "Leakdown Testing".

Harold
I'm going to take issue with wiki.
Its very hard to hold the piston at zero TDC the piston will travel downwards when air pressure
is applied if its off center.

I've found that it quicker and more exact if you remove the rocker arms and test at BDC.
Dan

P.S. With a high leak down reading..say around 25% or more
Air noise coming from crankcase...rings leaking
Air noise from intake..guessing the intake valve :)

A reading of <5% good <3%better <1%:D
 

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Discussion Starter · #12 ·
I would love to play with one of these.
The only problem is the cost...or as one of the Jawga gang would say..
Deep pockets...short arms.
 

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I've found that it quicker and more exact if you remove the rocker arms and test at BDC.
Dan
agree, at least for the Opel 1.9L, since I knew there was a problem, I just took all the rockers loose for my test, worked great. At least I know where & what the problem is now. :yup: Should have done this last fall, after the bad comp. test #'s, more that just a blown head gasket.....:slap::stupid:
 
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