[Fot] Camshaft recommendation

[Larry Young]

Yes, the down side to a smaller clearance is that the seat-to-seat 
duration and valve overlap will increase causing a loss of the low end. 
This page > http://tildentechnologies.com/Cams/Tip_Lash.html shows a 
case where the duration would increase about 32 degrees to about 4x86 = 
344 degrees. I like to call this the "tuning fork effect" it sets of all 
kinds of vibrations which can cause the valve to jump off the lifter and 
bounce off the seat at closing.

I did not intend to imply most smack the lifter, just that many do. This 
is a good reason to thoroughly measure your cam profile. Most stuff on 
the web talks about valve springs as the only cure for valve float issues.
  - Larry

On 2/20/2020 6:51 PM, van.mulders.marcel at telenet.be wrote:
>
> Larry, you say most camshafts smack the lifters hard. Will a smaller 
> valve clearance relieve this a bit? Has it disadvantages to set the 
> clearance smaller than recommended?(except that the valves will run 
> hotter)
> Marcel

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