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Old 07-10-2018, 09:23 AM   #1
egm
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Default No compression

Drove 31 Tudor into barn, running fine, next day wouldn’t start, no compression all 4 cylinders. Pulled head everything looks ok, valves move,new valves , 100 miles on them. Can’t understand how I lost compression in all 4 cylinders overnight. Any ideas? Thank you.
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Old 07-10-2018, 12:04 PM   #2
100IH
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Default Re: No compression

Look at the cam timing gear, they get damaged often.
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Old 07-10-2018, 12:21 PM   #3
1930artdeco
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Default Re: No compression

May also want to pull the valve cover and watch things move.


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Old 07-10-2018, 12:29 PM   #4
egm
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Default Re: No compression

Thanks will do
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Old 07-10-2018, 12:42 PM   #5
100IH
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Default Re: No compression

You can pull the side cover but you already have the head off. You said that you could see the valves move. Why?
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Old 07-10-2018, 01:01 PM   #6
1930artdeco
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Default Re: No compression

If the valves are moving then you should have compression. What led you to think of no compression in 24 hrs.?
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Old 07-10-2018, 01:03 PM   #7
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Default Re: No compression

Valves move up and down well distributor rod turns feel no slop feel tight to cam. Valves tight to seats. Not sure what to look for next. Head gasket looks as good as new.
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Old 07-10-2018, 01:06 PM   #8
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Default Re: No compression

Quote:
Originally Posted by 1930artdeco View Post
If the valves are moving then you should have compression. What led you to think of no compression in 24 hrs.?
me thinks the compression gauge doesn't work...
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Old 07-10-2018, 01:09 PM   #9
egm
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Default Re: No compression

Thought gas was bad, rebuilt carb no go, checked compression 0 at all 4
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Old 07-10-2018, 01:11 PM   #10
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Default Re: No compression

Put finger over hole no response.
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Old 07-10-2018, 01:29 PM   #11
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Default Re: No compression

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Originally Posted by 1930artdeco View Post
If the valves are moving then you should have compression.
Not necessarily. They need to open and close at the right time. I suggest pulling the side timing gear cover and looking at the gears.
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Old 07-10-2018, 01:33 PM   #12
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Default Re: No compression

Cam may have lost it's relation to the crankshaft - broken teeth on fiber gear. The procedure has been covered hundreds of times here. Good time to get familiar with the advanced search feature. Try it, you'll like it. Saves a lot of time. Then, if you don't understand, I'm here to help and others as well. The picture in your mind is basically what is the 4 stroke cycle. Got to picture it to understand it. Model As are simple but the 4 strokes and piston position concept is universal. The goal is not to get the car running, its get the understanding to know what to do with the basic test results.
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Old 07-10-2018, 01:49 PM   #13
Patrick L.
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Default Re: No compression

Pull the side cover off the timing cover and check every tooth.
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Old 07-10-2018, 04:21 PM   #14
egm
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Default Re: No compression

Teeth look good
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Old 07-10-2018, 06:56 PM   #15
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Default Re: No compression

So did you crank the engine and watch the gear turn as the crankshaft turned?
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Old 07-10-2018, 08:29 PM   #16
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Default Re: No compression

what kind of tappets do you have and what did you set your valves at? make sure the timing marks are still in line
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Old 07-10-2018, 09:14 PM   #17
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Default Re: No compression

Even if you wrung the teeth off the timing gear you would have compression in at least one of the cylinders,there is no cam position where a valve on all four cylinders open..so that rules out a valve timing issue. Stuck valves can cause it but you would have to have at least two stuck or burnt valves.Engine was running fine on shutdown so that rules out burnt valves,sticking is possible..any other issue would require 4 events to occur..at once...with no prior indication of a problem..
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Old 07-11-2018, 05:49 AM   #18
Patrick L.
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Default Re: No compression

If every tooth on the cam gear is in good condition and each valve has some lash and things are going round and round as they should, there should be compression. Have you added a wee bit of oil to each hole ?

As hard as the crank gear is to get off I would doubt that is the problem, but, at this point it might be worth checking. Something just isn't making sense.
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Old 07-11-2018, 07:51 AM   #19
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Default Re: No compression

It's time to consider your compression is your problem.

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Old 07-11-2018, 08:11 AM   #20
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Default Re: No compression

Quote:
Originally Posted by egm View Post
Put finger over hole no response.
In your first post you said you removed the head. Is it on or off now? - which hole are you talking about? I am very confused as to what has been done and what state the engine is as far as being apart at this time. Can't get much compression with the head off.
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