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Guest Anonymous

70 psi compression and 90% blowby. I think I'm fuct!!!

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Guest Anonymous

My marks all lined up at tdc when I put a new head on, but I have this situation. I had good compression (150)in the last head on 1 and 4 with 2&3 having problems. The car also started and ran. Now with this head (both E12) I have this. The blowby is what I can't get over. 90% What the hell. Anyone have good ideas on a really cheap lower end, or a cheap rebuild?

thanks

eric

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Guest Anonymous

do you know where the leak is? rings, pistons?

steve

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Guest Anonymous

Where is the blow-by blowing by ?

Surely with that much flow, you can hear it and determine where the big rushing air sound is coming from (intake / exhaust / rings).

If you had an engine that ran (even poorly), and now have 90% leakdown with just changing a head, I'd have to suspect valves not seated. Are you certain that both valves are shut when the test is run? Did you do a liquid test on the combustion chambers prior to the head install? (Test with liquid is done with the uninstalled head upside down, and you pour liquid into the chamber, spark plug installed + valves closed. If it trickles or runs past the valves into the ports you can see the evidence.)

What was the leakdown with the old head?

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Guest Anonymous

The blow by test was done with valves adjusted, and definately with both valves closed. I guess it would be escaping to the block past the rings. Even with the valve timing totally off, the leak down test should discover this. No bubbles through the radiator

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Guest Anonymous

What ended up getting it going?

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