Exactly right! I recently took a close look at 6 different TR cams.
The actually seat-to-seat durations averaged 10 degrees greater than
advertised. So, they tell us to use the numbers at 0.050 gross cam
lift. How do you compare two cams using 0.050 numbers when one runs
with a valve clearance of 0.010 and the other runs at 0.030? Not a very
useful standard.
Larry Young
Bill Babcock wrote:
> The funny part for me is that in doing this I've realized how
> potentially inaccurate all the talk about duration is. It's a big
> function of the clearance setting (I guess that should have been
> obvious) and one person's 270 cam might be another's 300. The closest
> to a standard seems to be .050 clearance measured at the valve collar.
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