Guys,
Interested in doing a simple compression test. A couple of questions 1. Warm or cold engine? and 2. All plugs out as each cylinder is being tested?
Thanks
Compression test
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john in kzoo
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Mark Nunn
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Re: Compression test
Don't forget to fully open the throttle during the tests. You can't compress air that can't get in.
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RajoRacer
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Re: Compression test
1: I prefer warm - 2: yes & 3: what Mark said !
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Mark Gregush
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Re: Compression test
It is ok to have the throttle closed or open, I really have never seen a difference between the two. I do my test cold, I am more interested in starting compression then running. Again, you can do them both to see how much difference between the two readings.
I know the voices aren't real but damn they have some good ideas! 
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john in kzoo
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Re: Compression test
Compression test completed Saturday on a very cold engine (30 degrees) got 45#, 40#, 40#, and 40#. Plugs looked good #1 was sooty though
Thoughts??
Thoughts??
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Tim Rogers
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Re: Compression test
Run the wheels off of it or do a complete rebuild.
<o><o><o><o> Tim Rogers - South of the Adirondacks - Forum member since 2013 <o><o><o><o>
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Quickm007
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Re: Compression test
How to do a compression test on engine without starter ?
Super Mario Bross 
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john in kzoo
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Re: Compression test
I opt for running the wheels off........
Quickm007 - Crank and crank and crank
Quickm007 - Crank and crank and crank
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Fire_chief
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Re: Compression test
Mario, it is still the same process.
The only thing different is that you get to turn the engine over with the crank
The only thing different is that you get to turn the engine over with the crank
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kmatt2
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Re: Compression test
Your cold compression test numbers, 45,40,40,40, would sujest why #1 plug was sooty. You are getting a little oil past the rings in #1 and #1 plug has a intermitid misfire. Try doing a wet compression. test with a little oil in the cylendars and all numbers will come up, with #1 coming up the least. Your cold dry numbers of 40 lbs are not that bad. I would keep driving the car, keep up with your maintenance and check the #1 coil & timer connections, replace #1 plug if needed.
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john in kzoo
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Re: Compression test
Thanks Guys.....
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Charlie B in N.J.
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Re: Compression test
I much prefer comp testing a low comp engine like the T when it’s cold. It gives a truer situation concerning starting the T when cold. Testing hot will give a false reading regarding cold starting. A modern with a comp of say 150 lbs. or better is relatively in affected by a 5 or 10 lb. drop. On a T that could be the difference between easy starting or not on a cold day. Do a dry then a wet test with the choke & throttle wide open. Write the results down. Don’t trust to memory. A VERY informative test concerning your engines condition. Especially if you’re pulling the head for no reason.
Forget everything you thought you knew.
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Oldav8tor
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Re: Compression test
Sooo.... what is the "good" compression range?
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Tim Rogers
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Re: Compression test
55 PSI would be nice...
<o><o><o><o> Tim Rogers - South of the Adirondacks - Forum member since 2013 <o><o><o><o>
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Quickm007
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Re: Compression test
Thank you guys, I will crank, crank and crank but my shoulder is painfull right now. Hope I will recover soon... 
Super Mario Bross
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john in kzoo
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Re: Compression test
It's really easy with all but one plug out and the throttle positioned all the way open as well
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KeithG
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Re: Compression test
Super Mario, Befriend a football player with wide shoulders and strong arms.... 
Keith
Keith
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