I use the 'rule of nine' method to adjust valves but there is a rather
interesting result when setting the lash on reground cams. That result is
that if you set a valve when its 'partner' is exactly on the peak of the
lobe, then the valve you are setting won't necessarily be on the base
circle of the cam. That means that the lash will be larger than you want it
to be.
To get the clearance right, I have to turn the engine about another quarter
turn.
And no, I haven't noodled out exactly why, I just know that's the way it is
on four or five different cams I've worked with.
uncle jack
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