5.0 stockers/ distributors

[Tim Ellis]

Update, I pulled the cam out to take a look. I believe the dowel pin was a real tight, possibly damaged, fit. I think the cam sprocket wasn't snugged tight to the cam, and that allowed the cam to walk backwards. I didn't check cam end play last time {silly me} . This time I will. BTW I did check timing with a regular timing light, no difference. Thanks for the brain trust.

[HawkBrosMav]

I may be naive here, but can someone explain the idea of the cam walking back and forth changing timing? It seems to me the the timing would be in the same place the only thing changing would be where the lifter contacted the lobes? even if the timing gear was loose if the pin was in the locating hole I don't see how the timing could change but maybe 2 or 3 degrees just depending on the angle the gear got cocked, but no way does it change 15 unless it was falling off the locating pin....

Just looking for an honest explanation, not trying to be a smart *** or anything.

Thanks
Brad

[ALMACK]

Originally Posted by HawkBrosMav

I may be naive here, but can someone explain the idea of the cam walking back and forth changing timing? It seems to me the the timing would be in the same place the only thing changing would be where the lifter contacted the lobes? even if the timing gear was loose if the pin was in the locating hole I don't see how the timing could change but maybe 2 or 3 degrees just depending on the angle the gear got cocked, but no way does it change 15 unless it was falling off the locating pin....

Just looking for an honest explanation, not trying to be a smart *** or anything.

Thanks
Brad

Brad:
The way I understand it is when the cam on a SBF moves forward in the block (walking) it will spin the dizzy shaft more in the counterclockwise direction (as viewed from above).
This effectively advances the ignition timing on a SBF.