Quote:
Originally Posted by wgirardot
I am in the process of putting my stock '82 SC engine back together after headstud replacement. The only other thing done during this was a valve job, with .14 mm removed to clean up the mating surface on all 6 heads. All else is original: pistons, cylinders, .25mm base gaskets etc.
I have set camshaft timing to 1.56mm on both sides ( right in the middle where it is specified for a 930/16 motor ). Now I am checking valve to piston clearance on 1 and 4 and seem to have a problem on both sides intake clearance. Left side is .75mm of clearance and right side is .55mm. Both the exhaust exceed the required 2mm min clearance so that is good.
What can be done to increase intake clearance as Wayne's book call out 1.5mm minimum ? I am kind of stumped what could be going on with a bone stock, unmolested, motor where the only thing that was done was head fly-cut of a mere .14mm
Bill
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Which cam are you running? Also what was your deck height?
To increase your intake valve clearance you will need to RETARD your cam timing slightly. Try for 1.45mm (with 0.1mm valve lash) and then re-check your clearance.
You should get near sufficient intake clearance, but double check your exhaust clearance as this will reduce slightly when you retard the timing.
You can run less than 1.5mm clearance on the intake but the extra is a nice insurance. Maybe 1.25mm is enough. You'll find the piston is on its way down and away from the intake valve....