No Compression

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jte8969
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No Compression

Post by jte8969 »

I had put up my truck for the summer because of frustration and just to hot to work outside. My problem is i'm not getting compression. I rebuilt the 352 and had the timing 180 off and bent push rods. I replaced them but now im not getting compression. It has hydraulic lifters so the valves do not need to be adjusted. I have the standard length in there. Any ideas??
1967 F100 project!
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convincor
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re: No Compression

Post by convincor »

is there "0" compression or just real low??
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jte8969
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re: No Compression

Post by jte8969 »

I only checked 1st and 5th cylinders. thats all I had time for today and there was 0 compression
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willowbilly3
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re: No Compression

Post by willowbilly3 »

If it bent the pushrods it probably bent the valves too.
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convincor
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re: No Compression

Post by convincor »

or the valves are stuck open.
Check and make sure the pushrods are seated correctly in the lifter. Should be able to look down there with the valve covers off. They can get hung-up at the side of the lifter which will hold the valve open all the time.
Can you do a leak down test?
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re: No Compression

Post by FORDification »

No compression means either the valves are stuck open or the valve(s) aren't opening at all. Pop the valve cover and watch the rocker arms while you crank the engine see if they move. You can also get a good idea on the condition of the pushrods.

I bought a brand X vehicle several years ago with 0 compression on one cylinder. Popped the valve cover off and saw that the rocker arm had come loose. Reinstalled it, set it, and it ran like a top.
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oldschoolrods
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re: No Compression

Post by oldschoolrods »

did you remember to put the pistons back in those holes??? :D jk like the others stated best thing to do is pop the valve cover and see if they open and close.
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re: No Compression

Post by jte8969 »

I have never done a leak down test. I dont know how to do one
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convincor
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re: No Compression

Post by convincor »

does you compression tester have a airhose fitting? if not, get one that does and hook it up to compressed air. List for where it's leaking from.
here's how- http://www.geocities.com/dsmgrrrl/FAQs/leakdown.htm
or here- http://www.carcraft.com/techarticles/11 ... index.html
With the "0" compression you don't need to have the double gauge set-up. Just need something the connect compressed air to the spark plug hole. You'll be able to hear whether it's leaking out the exhaust or intake.
And you'll want to pull the rocker shafts off when doing this.
Here's a gauge with a quick connect- http://www.partsamerica.com/ProductDeta ... yCode=3491
68 Custom Cab Shorty, 390, C6, 9"-3.50:1 Currie T/L
"Still Plays With Trucks"
http://s101.photobucket.com/albums/m41/convincor/F100/
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