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compression test

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Old Jan 18, 2012 | 10:27 PM
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compression test

What is the compression suppose to be for '77 F-250 with
460.
 
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Old Jan 18, 2012 | 10:54 PM
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Anything over 130 psi should be good on those tugboat motors. Small cam and very little lift and anemic compression ratio isn't going to produce much.

150-160 would be great. 120 psi is OK.

Be sure to do a dry and wet test and make sure to crank the engine over a couple revolutions with the carb blocked WOT during the test to get the best number for each cylinder.

Josh
 
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Old Jan 19, 2012 | 12:25 AM
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Also removing all your sparkplugs first and replace them after you have completed testing all cylinders, your starter will love you.

If you do just be sure to number each plug wire.
 
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Old Jan 19, 2012 | 04:49 AM
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Well I think I may have a problem . But first of all I could pull those wires blind folded and reinstall with no problem. This is how the numbers went. No.1-100 lbs. No.2 110 3-90 4-90 5-90 6-95 7-87 8-92
 
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Old Jan 19, 2012 | 05:07 AM
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You did crank each cylinder through 4 or 5 compression strokes right? To make sure it maxed out? That was dry,are you going to repeat wet?
 
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Old Jan 19, 2012 | 06:15 AM
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Just to add....

Did you start out with a good fully charged battery?

Hand held or screw-in compression tester?

and as mentioned:

5 complete compression strokes

wet test results?
.
 
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Old Jan 19, 2012 | 06:59 AM
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Battery is ex excellent as a matter o fact I have two wired in parallel. Tester is screwed and when the gauge stopped rising I stopped. As far as the wet test I live in Washington St and I don't have to test, I know its wet. Just kidding. I didn't know about wrt test until I was finished. I will definitely let u know how that went
 
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