Odd compression test update

9njunkie · Jul 25, 2017

Hey y'all,

Here's the results. Double checked all valve adjustments. One was very slightly off, so it was adjusted and only gained 10 psi on that cylinder. All other valves checked out ok.

We ran compressed air to the dead cylinders and had lots a air entering the crank case with both valves closed. So it looks to be a ring job at the very least as I had initially suspected. Bummer.

Anyhow the original question remains unanswered and am asking advice on things to look for during the tear down ... that is what would cause such a drastic damage to rings? At the moment without having torn motor apart I would guess an oil pump falure of some type? Any suggestions anyone? Anybody have a way of testing the oil pump once off the block?

Thanks again for all the help and great advice[/code]

deanostoybox · Jul 25, 2017

starting fluid

JMOR · Jul 25, 2017

(quoted from post at 14:00:17 07/25/17) Hey y'all,

Here's the results. Double checked all valve adjustments. One was very slightly off, so it was adjusted and only gained 10 psi on that cylinder. All other valves checked out ok.

We ran compressed air to the dead cylinders and had lots a air entering the crank case with both valves closed. So it looks to be a ring job at the very least as I had initially suspected. Bummer.

Anyhow the original question remains unanswered and am asking advice on things to look for during the tear down ... that is what would cause such a drastic damage to rings? At the moment without having torn motor apart I would guess an oil pump falure of some type? Any suggestions anyone? Anybody have a way of testing the oil pump once off the block?

Thanks again for all the help and great advice[/code]

il pump failure would result in bearing failure & likely engine seizure well before you would notice ring failure.

Bob · Jul 25, 2017

"So it looks to be a ring job at the very least as I had initially suspected."

You will NEVER fix a "zero compression" situation with a simple ring job. Even with the rings completely missing you would have a little compression.

If you truly have zero compression and it's not leaking through the valves you have a BADLY damaged piston... a hole in the top or a large part of the ring land area cracked off, broken, or burned away.

It will be interesting to hear what you find!

JMOR · Jul 25, 2017

(quoted from post at 14:49:29 07/25/17) "So it looks to be a ring job at the very least as I had initially suspected."

You will NEVER fix a "zero compression" situation with a simple ring job. Even with the rings completely missing you would have a little compression.

If you truly have zero compression and it's not leaking through the valves you have a BADLY damaged piston... a hole in the top or a large part of the ring land area cracked off, broken, or burned away.

It will be interesting to hear what you find!

aybe an oil pan full of sleeve?

9njunkie · Jul 25, 2017

Hey Bob and JMOR..

Hmm ... yes this could be interesting. What I meant by saying zero PSI was extremely low mabye 5 psi actual reading... just enough to flick the needle on the gauge a lil.

As for the condition of the crankcase contents. We did drain that today before I got pulled away to work on another project. Oil was in what I considerd to be in great shape. Good color, good smell, no gas, no antifreeze, and no metal. I even swiped a magnet around on a stick from inside the drain plug around the bottom of the pan and it came out clean.

Disassembly starts tomrrow, will post findings

Thanks again very much

Odd compression test update

9njunkie

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deanostoybox

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JMOR

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Bob

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JMOR

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9njunkie

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