The cam grinder will call-out the checking clearance spec for any particular
grind. I've seen that number vary from .010-.050, depending on
grind/grinder. In addition to using opening & closing points for reference,
the lobe
center point is accurate on any symmetrically ground lobe. The inlet lobe
center
on the Kas "D" is 109* atdc. This is the point where the inlet will be @ max
lift (33* btc + 180* + 71* abdc = 284 ~ 2 (crank/cam rotation 2-1) = 142 - 33
initial btdc = 109) This means that if the cam is ground & degreed properly,
all 3 numbers will be right on. Note when establishing max open point, don't
indicate to max lift. Establish a point a few degrees before & after with an
equal lift amount slightly less than max lift, just like establishing TDC on
a piston with a piston stop. It's hard to get it exact when it rolls over
absolute TDC.
HTH,
Glen
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