Is cam calibration going on? Absolutely! The closest you can be to .006 @51, the faster you will be. Briggs takes over 3600 points proving each cam is the same, so why are these engines so different at the track.
The biggest tolerance is the cam timing spec. At .006 you get an 8 degree window. 51-59 degrees, At 2-3°you would easily win the race and 4°, is the max so why 8° spread. That is 4° on each side. First number at .006 @51 is the optimal position you want your cam for the max cam timing power and corner exit pull with straight away speed.
This is no mystery. It’s been published over and over. The engine builders understand it and give it to their best customers. Been doing it since the flat head days. You just did not know!
You lock the cam In place and put pressure on the crank to twist the cam at the compression release hole. Remember engine builders say no more than the 4°.
It’s easy to fix. Briggs could wright the rules to 1/2 degree from the manufacture spec, put in the center lines and the problem would be over but it would be new short blocks for many and the same kids would no longer be winning.
It’s just science and engineering with some simple math and a degree wheel. We all took it in high school, just did not know how to apply it.
