On Fri, 10 Mar 2006 Lizirbydavis@cs.com wrote:
> How are the valve stem/rocker arm clearances established? Why does the
> clearance need to be increased with higher ratio rocker arms and higher lift
>cams?
> I have a GP2 cam and 1.65:1 roller rockers. The valve gear clatter with the
> recommended clearances is much more that I expected. What harm will come
>from
> closing up the clearances? (not that I would!)
> Joe Davis
More cold clearance means more time "on the valve seat" where the heat
transfer takes place. Bigger cams mean more heat - to get the heat
transfer you need more time on the seat.
Valve clatter does not come from valve lash, per se. Your valve clatter is
more likely slop in the rocker shaft, loose valve to stem clearance, loose
lifters, etc.
If you tighten up the valve clearances, you WILL burn valves. If you want
to play with this, you can tighten the intakes, but NEVER tighten the
exhaust clearances unless you like doing valve jobs often.
rml
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