Head rebuild and intsallation

Started by cunninac, 01:04:20 PM / 25-Jan-17

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cunninac

How's it going guys. I am running into a compression problem on my CA20E. I was blowing smoke upon start-up. The spark plugs on cylinders 1 and 2 were pretty fouled and a compression test gave me low readings as well, the oil test didn't change those numbers. I pulled the head and had a shop rebuild it for me, waste of $200, and I reinstalled it following the procedure laid out in the Nissan Service Manual. After dealing with vacuum line routing problems, I got it all set up and dialed in. The car still won't start. Another compression test shows 80 psi across all four cylinders. I rechecked the torque on the head bolts, two were low so I went through the process of re-torqueing them. The compression is still low. Before I pull the head and run a straight edge across the mating surface of the block again, what could be causing this issue? Any help would be greatly appreciated.

Cheers

rednucleus

Did you check compression wet as well?
Still think you have a valve adjustment or timing problem. Just was browsing elsewhere and read that if too tight hydraulic lifters can keep valves slightly open.
Also curious did you get new head bolts or use the old ones?   

weitrhino

In the motorcycle world I learned that overly tight valves will cause a running engine to take longer to rev down when the throttle is released. That shouldn't be an issue with hydraulic adjust valves AFAIK.

James, check your PMs.

cunninac

#3
Quote from: rednucleus on 02:06:47 PM / 25-Jan-17
Did you check compression wet as well?
Still think you have a valve adjustment or timing problem. Just was browsing elsewhere and read that if too tight hydraulic lifters can keep valves slightly open.
Also curious did you get new head bolts or use the old ones?

I did check the compression wet and all cylinders were still low. I'll check the torque on the valves first thing today and see if that could be the issue. I'd hate to pull the heads and find this is the problem. Thanks for the info guys, I appreciate the help.
Post Merge

Quote from: rednucleus on 02:06:47 PM / 25-Jan-17
Did you check compression wet as well?
Still think you have a valve adjustment or timing problem. Just was browsing elsewhere and read that if too tight hydraulic lifters can keep valves slightly open.
Also curious did you get new head bolts or use the old ones?

I did not get new head bolts. I am using the 30+ y/o ones... now that I type this I see the error in it. HAHA shit.