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emtrucking
10-21-2009, 10:53 PM
ok have a 87 with a fresh rebuild 30over pistons all forged and roller.Car runs great but has a loud clacking/loose rocker sound i guess. but the builder said it should sound like that and gn roller sounds like that,motor runs good but has that noise.he also said that poss after a couple of oil changes it may go away. Any help?

kenmosher
10-22-2009, 04:39 PM
If it's clacking it's probably one or more of the following:

Incorrect length push rods
Cheap/wrong lifters
Oil gallery plugged (or cam plug missing/leaking/loose on lifter gallery)
Incorrect preload on the lifters (i.e. too much collapsing the lifter OR too little allowing things to "bounce")
Incorrect valve spring pressures
If they are roller rockers, are they clearanced (either by the builder or from the factory) adequately for the rocker shaft towers? Sometimes you have to "touch" the towers with a grinder to get enough clearance due to core shift in the head casting
Low oil pressure or inadequate oil to the top end