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December 9 2011 at 10:49 AM
Bob  (Login machoneman)
from IP address

Response to What I found so far

good vid btw. The .036 is way too much freeplay as .005 to a max of about .010 is all one should have. As a result of the cam wandering back and forth, the cam and ditzy gears ran off the edge, so to speak. This accounts for the severe edge wear of your ditzy gear where clearly the 'path' wasn't centered on either gear.

Consider the pics we've all seen of ideal drive and coast side gear mesh on, say, a 9" Ford rearend gearset....the same applies here. The Comp Cams excerpt I've replayed below mentions some of the effects of excessive end play, but doesn't mention rapid gear wear as another side effect when the gears ride off the edge.

That's my guess!

Checking Camshaft Endplay
Camshaft endplay refers to how much a roller cam is allowed to move back and forth in the engine. .005 to .010 endplay (My edit: this is TOTAL endplay) is required to eliminate the possibility of wear occurring as a result of interference between the cam and other engine components. Excessive endplay is detrimental as the cam will be misaligned to the lifter bores, causing the roller wheels on the lifters to run off the edge of the lobes instead of on the center. Another important effect of camshaft endplay is that as the cam moves back and forth, it advances and retards the ignition timing at the distributor gear (My edit: and also allows the gears to run-off the edge and result in rapidly wear).

The proper amount of endplay is between .005 and .010. This can be checked using a dial indicator and magnetic base on the front of the engine. To do this, push the cam as far back in the engine as possible, zero the indicator on the upper timing gear, and then pull the cam as far forward as it will go. The indicator reading is the amount of endplay in the camshaft.

This message has been edited by machoneman from IP address on Dec 9, 2011 11:51 AM

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