You should only have to adjust the valves on an hydraulic lifter once for
the life of the engine. The procedure varies from book to book, but this is
the way we all did it at the dealership. With the valves in the seated
position, tighten the nut until you can't spin the pushrod with your
fingers, turn nut one half to 3/4 of a turn. Yes, you tighten them too much,
the valve won't seal tightly and if you drive it that way, it can burn the
valve seat or valce face in short time. The valve and seat is dependant on a
tight seat to dump exess heat, not to metion good power and a smooth running
motor.
Thomas M OBrien wrote:
> At the risk of sounding "mechanically challenged", I adjusted the valves
> on my newly broken in 283 this weekend according to the specs in the
> Motors Manual and Shop Manual and now my truck wont start. The starter
> will crank the motor and makes a whining sound that wasn't there before,
> and then a puff of air out the exhaust.
>
> I warmed up the engine, turned the crank to # 1 TDC, and adjusted
> appropriate valves; then cranked over to # 6 TDC and adjusted the rest.
> Checked distributor to double check rotor in correct firing position.
> Rolled pushrods between fingers to take out lash then turned 1/2 turn
> down.
>
> Is it normal to have to turn down the adjusting nuts a lot after just
> breaking in a new rebuilt motor - like around 4 turns or more? Am I
> missing something? Did I screw up the timing so it wont fire at the
> right moment? Is it possible to turn down the adjusting nuts too far?
> Interference between piston and valve?
>
> Thanks for your help. Gotta love these old 283s.
>
> Tom O.
> 60 Apache K20.
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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