Valve adjustment question
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Valve adjustment question
I'm having an interesting situation with my 383 in my 76. I'm running AFR 195cc street eliminator heads; Comp Cams 12-433-8 Hydraulicc roller cam Duration 236/242 at 050 inch lift, .520/.540, crower retrofit roller lifters and rockers, Edelbrock air gap intake, Holley 750 double pumper, stock HEI distributor, Hooker sidemount headers, 9:8:1 compression, behind a TH400 with a 3,000 stall. The motor seems to run fine, but when I adjusted the valves they would not allow me to set any pre-load on the exhaust or intake valves at number two and four. Any amount of pre-load with these two cylinders causes the car to idle and run poorly. All of the other valves adjusted normally. Again the motor seems to run great without any pre-load at these two cylinders. What could be causing this situation, is there anything I can do to remedy it if needed, and is it something I should be worried about in the first place? I have not had a chance to have it put on the dyno so what are your best guesses at how much flywheel horsepower this motor should be making?
Melting Slicks
Joined: Oct 2002
Posts: 2,317
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From: St Louis MO
It sounds like any preload on those 2 cylinders holds the affected valve off the seat and therefore causes the problem. This could happen if the plunger in the hydraulic roller lifter is bottomed and is not becoming pumped up to eliminate the lash, i.e., the lifter is stuck/bad. Can you verify that the plunger has its proper range of travel? (Try observing if the center of the lifter is stuck approximately 1/10 inch below the retaining clip at the top of the lifter.)
If this is true, the lifter may be bad, or it could be caused by a restriction preventing oil pressure into the lifter.
If this is true, the lifter may be bad, or it could be caused by a restriction preventing oil pressure into the lifter.
Last edited by larrywalk; Mar 22, 2009 at 11:34 AM.
Safety Car
Joined: Oct 2004
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From: Youngstown Ohio
I had a 383 similar to yours but w/slightly differently cam (286HR, 230 dur. @ .050, .560 lift).....flywheel HP was about 460, and rear wheel HP was 373. With 4.11 gears best E.T. was 11.62. Sounds like you have 11 second potential there.
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Great looking car and I bet it is a beast on the strip/street.
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Le Mans Master
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From: columbus oh
...however this is true more so with cast iron heads ......aluminum heads will add some lash as they heat up.....
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