Still doing the "Works Midget's" vintage race motor and believe I can now
check cam timing with my eyes closed and a stewardess searching my pockets
for spare change. But my inquiring mind needs to UNDERSTAND!
I've got a Piper cam with a 107 ATDC spec. Seems to me then that if the key
slot is correct and I install my timing chain wheels in the standard
position (dimple to dimple), then when #1 intake pushrod is at its highest
point (the top of the cam lobe), I should be showing 107 ATDC on my degree
wheel.
>>>>QUESTION #1: Is that correct thinking?
(Please assume at this point that I've zeroed my wheel at TDC using the
piston stop method and determined my cam lobe top by using a dial
indicator).
Now let's say my dog ate my woodruff key and all I have left is a 1-degree
and a 4-degree offset keys. I pop in the 4' key in the "advance" position
(camshaft being located a little clockwise relative to the chain wheel). I
check the cam timing and come up with 102 ATDC at full lift on #1 intake.
>>>>QUESTION #2: Is a 1-degree error about in the ballpark given
manufacturing tolerances and bozo installer?
Now let's say I'm fed up about to here ^ with un-doing everything and
changing woodruff keys and finding TDC and getting the cam lobe top, etc
etc. and button the whole thing up, then....
>>>>QUESTION #3: If 102 is 5' advanced cam timing over the grinder's spec
of 107 (valve event occurring earlier in the rotation of the crank) about
how much lower in the RPM range would this pull my power band?
And if this means I'm going to have all of my torque between 700 RPM and
3500RPM and be flat after that, then....
>>>>QUESTION #4: Does anybody have a stock key they can express mail me?
Thanks for your insights!
JohnD
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