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Low compression and lifter install
#1064222
09/24/13 11:29 AM
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Joined: Aug 2012
Posts: 108
OP
Wheeler
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Hey guys, I've been having a few hick-ups with my recent turbo build. I have about 800 miles on it since the rebuild and decided to do a compression test to make sure everything is seating well. I have almost no compression(40 psi) on cylinder #4 and very low on all others(cheap H.F. gauge might be wrong). the engine seems to run ok but the turbo might hide the problem. When I installed the lifters I cleaned, bled, and filled with diesel as per instructions found somewhere on the forum. They were extended and not compressible when installed. The haynes manual showed bleeding the lifter thru the rocker with a small pin but my rockers don't have a hole to bleed them. I was hoping that they would have slowly leaked down on their own, but this might not have happened and the valves might not be closing completely. The njv head and rockers maybe are off a forklift or something. They came with the starion donor engine and looked newish and uncracked, but had really crappy castings without id marks
Should I remove the lifters and bleed them compressed and reinstall?
"Turbobitchero" (named by jealous wife) 87 swb base, 89 starion intercooled turbo engine, Bouncy seat, posi in rear, "miller locked" in the front with manual hubs, 3" BL, 305/70/16 bfg's. Sponsored by IAWDLR Racing
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Re: Low compression and lifter install
[Re: jwthemechanic]
#1064223
09/24/13 07:33 PM
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Joined: Jan 2001
Posts: 13,649
Web Wheeler
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If you are using nonjv head and valves, which normally came from a non hla engine, your valve stems may be too long to close with hla rockers. I had this happen once. You either need to use the manual adjust rockers or change the valves. I had this happen once. To test it, see if a rocker on the cam base circle (fully open) will rock with hand pressure a few thousandths. You can feel a slight give in the rocker. If the rocker is dead solid, you gotta change stuff out...
Not responsible for advice not taken...
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Re: Low compression and lifter install
[Re: fasteddy]
#1064224
09/24/13 07:59 PM
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Joined: Aug 2012
Posts: 108
OP
Wheeler
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Thanks! This might be the case and to to add to it the intake valves were resurfaced. I replaced the ex. valves because there were inclusions/pits in valve face when ground. Not sure if the valves are mech type as the keepers were the same as the ones on my old stock head and I thought I read somewhere they use different keepers. The ex valves were the same length as new replacement ones. This sucks as I don't have a garage to work on it anymore. Damn turbo hides the problem pretty well as it drives quite well.
Last edited by jwthemechanic; 09/24/13 08:07 PM.
"Turbobitchero" (named by jealous wife) 87 swb base, 89 starion intercooled turbo engine, Bouncy seat, posi in rear, "miller locked" in the front with manual hubs, 3" BL, 305/70/16 bfg's. Sponsored by IAWDLR Racing
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