Compression test numbers..?

Bennett

 
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Feb 1, 2002
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Ran a compression test for a friend today on a mid 70s 2F. He has a receipt form the previous owner showing a rebuild ($2500) 15k miles ago.
The truck really runs fine and has no oil consumption.. I pulled all the plugs and open the throttle plate and turned it over 10 times on each plug.

Here is what I got..

110 110 110 110 105 110 dry

110 110 110 110 110 110 wet (oiled)...

thinking I had a bad gauge I tried another and got the exact same readings.
I am thinking I have good tight rings but 110 seems low?
I put a borescope in each cylinder and very clean wtih no carbon buildup and cross hatching on cylinders still visable.

why such low numbers and is there reason for concern?

thanks
 
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Poser

Oh...Durka Durka Durka.
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Adjust your valves and try again....
 

honk

 
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Maybe retorque the head, but tight valves will do that..

Different guages do often give different results but you said you tried two. Are you using the type of guage with a push in rubber sealer? Those suck - the screw-in type with a good o-ring gives better results.
 

Bennett

 
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honk said:
Maybe retorque the head, but tight valves will do that..

Different guages do often give different results but you said you tried two. Are you using the type of guage with a push in rubber sealer? Those suck - the screw-in type with a good o-ring gives better results.
they were good hasting gauges with O- rings...
 

Pin_Head

 
 
 
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Bennett said:
why such low numbers and is there reason for concern?

thanks
If it is not the gauge and the valves aren't leaking on every cylinder, maybe the PO used flat top pistons when he should have used domed ones. I am not sure that this would account for the compression numbers. If it runs fine and it doesn't burn oil, I wouldn't lose any sleep over it.
 
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