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1972 240z New piston rings, valve job, new gaskets and seals HELP

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1972 240z New piston rings, valve job, new gaskets and seals HELP

Old 01-07-2013, 06:42 PM
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1972 240z New piston rings, valve job, new gaskets and seals HELP

I have been working on getting a 1972 240z back on the road and have been prevented from doing that. This has been unfortunately one big headache lately. When I first got the car what I thought was just a normal need of properly adjusting the carbs was really a miss on cylinder five due to a bent valve (that's the reason it wouldn't idle smoothly under 1,000 rpm). I thought it was rings so i replaced all the rings, turns out it was a bent valve so I had a valve job done at a local machine shop. I have got everything back together, I adjusted the valves 3 different times, first couple times i didn't adjust them properly, 3rd time I finally got it right by doing each valve separately and having the point of the cam lobe pointing straight up. Now here is the crazy part. I understand that the rings haven't been given a chance to properly seat into the cylinder yet, but in cylinders 2 through 6 I have about 125psi, in cylinder 1 it is only registering 60-65psi. I did a wet compression test in cylinder one and there was no change in the compression reading. I'm using one of the screw in compression testers just for some extra info. I haven't gotten the engine to fire yet. I know I have spark, fuel is something I'm a little unsure of, the gas has been sitting for about 2-3 months and I know that the floats aren't set to allow 23mm of fuel (it is less unfortunately). But my biggest question is why do I have such low compression in cylinder one? I made sure that the ring gaps were facing opposite directions even. Any ideas would be great. Thanks

Ben
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