[DeTomaso] rocker arm adjustment
JDeRyke at aol.com
JDeRyke at aol.com
Mon Jun 14 15:20:56 EDT 2010
Justin, are you sure the assembly was done properly? By that I mean, the
rocker pivot shaft inside each of your rocker arms have a flat spot for the
adjusting nut to bear on. If the rocker was installed with the centeral pivot
180 degrees out, you'll be trying to tighten a flat nut against a
cylinderical surface. Forgive me but I've seen even experienced for-pay engine
builders do this, and it always ends in curses and a tear-down. Where nothing is
found to be wrong so a reassembly with the same paets- done correctly-
mysteriously works fine.
Second point: valves wear-in against their seats, lifters wear-in on their
cam lobes, bubbles in the oil inside hydraulic lifters very slowly bleed out
which changes the adjustment, and even (apparently) metal stretch on the
studs, nuts and setscrews all tend to change a 'final' rocker arm adjustment.
It took me three tries over a 2-month period to get mine hot-adjusted
properly. Since then, they've held for 19 years! FWIW, I use Rhodes hydraulic flat
tappets, Sharp full-roller rockers and a Ridgeway stud girdle on our
engine. Good luck- you'll get it eventually- J DeRyke
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