Also, during the short time the exhaust valve is closed some of its heat gets
transferred to the seat. If that time is
too short because of less clearance the valve gets hotter--not a good thing.
My cam grind specified 0.012" for the intake and 0.014" for the exhaust (not
sure why).
Bob
On 6/19/2011 3:25 AM, Greg Lemon wrote:
> You get a little more valve lift (like having a slightly hotter cam) if you
> tighten the gap. However, as things heat
> up and the metal expands you may not get the valve to close all the way, and
> hot gas will get by and burn the valve.
> I have never read anything suggesting you should tighten the clearances up
> for a little more performance, the very
> limited benefit is no doubt not worth the very real risk of the burned valve.
>
> Greg Lemon
>
--
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Bob Spidell San Jose, CA bspidell at comcast.net
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