No, it isn't measuring the actual cam clearance. It is, however, a
convenient place to measure. Therefore, the numbers that are published for
this set the correct clearance for the cam, ASSUMING that you still have the
original ratio of rocker arms. This number changes if you change the rocker
arm ratio. According to Vizard, this number is derived by multiplying the
desired cam clearance by the ratio of the arm, therefore, if .012" is the
correct lash with a 1.25:1 ratio arm, then dividing the .012 by 1.25 yields
.0096 as the cam clearance, multiplying this by the 1.5 ratio yields a
"corrected clearance" of .0144 for the same cam when running 1.5:1 rocker
arms. Since .01" is probably the original cam clearance number (I doubt that
it was really .0096), the correct amount of lash should probably be .015".
David Lieb
1972 RWA Midget
2002 GTI for Trish to beat me at autocross with
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