nm9stheham
Well-Known Member
Max1196 kindly followed up on this topic with dimensions on the Chevy 4* key can Chevy crank snout and SBM cam snout diameters and radii. I really appreciate his refining this matter with good data!
He reports that the 4* Chevy offset key is .048" and the Chevy crank snout diameter is 1.247". That works out to 4.4 degree's offset for the 4* Chevy key in the Chevy crank. (It may become a bit less as the key way in the crank hub may cut the key a bit: I would not think they would actually angle that key's upper part's sides at 4 degrees from the lower part's sides, but just cut the 2 parts parallel. The upper end of that upper part would be at something less than the 4.4 degrees as it is further out from center.)
Yeah, that would be a LOT on a Mopar cam snout. It works out to 5 degrees physical cam change with an SBM cam snout diameter, (rounding down a bit from 5.2*). So yes, the crank change, and ICL change would be 10 degrees! Maybe use it with a -4 degree slot on the crank hub to get a +6 degree changes.
With the offset on a 2 degree Chevy key would work out to about 5 crank degrees when used with an SBM cam. Again, maybe use it in conjunction with the key slots on the crank sprocket to adjust things in.
He reports that the 4* Chevy offset key is .048" and the Chevy crank snout diameter is 1.247". That works out to 4.4 degree's offset for the 4* Chevy key in the Chevy crank. (It may become a bit less as the key way in the crank hub may cut the key a bit: I would not think they would actually angle that key's upper part's sides at 4 degrees from the lower part's sides, but just cut the 2 parts parallel. The upper end of that upper part would be at something less than the 4.4 degrees as it is further out from center.)
Yeah, that would be a LOT on a Mopar cam snout. It works out to 5 degrees physical cam change with an SBM cam snout diameter, (rounding down a bit from 5.2*). So yes, the crank change, and ICL change would be 10 degrees! Maybe use it with a -4 degree slot on the crank hub to get a +6 degree changes.
With the offset on a 2 degree Chevy key would work out to about 5 crank degrees when used with an SBM cam. Again, maybe use it in conjunction with the key slots on the crank sprocket to adjust things in.
