Degreeing Cam / Offset Keys available?

[nm9stheham]

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.

 

[360duster]

great Info, thanks!

i finally got my cam into spec with 2° Advance trough the Timing set and a 1° Retard trough offset cam Key.....now it is 105.5° centerline, i´m satisfied ;-)

We´ll see in spring how it works ;-)

Michael

 

[nm9stheham]

What offset key did you use in the cam?

 

[360duster]

1°....the smallest that´s in the kit P4286500.

 

[nm9stheham]

OK, so you found that kit. Was it NOS or from a regular sales outlet?

 

[360duster]

was NOS, guy over here had it for years on the shelf....good for me ;-)

Michael

 

[RustyRatRod]

Good GAWD. Just use a good quality timing set with the nine keyways and you don't have to worry about any of this garbage.

 

[360duster]

yeah, next time for sure....as always room for improvement ;-)

Michael

 

[lilredridinghoo]

was NOS, guy over here had it for years on the shelf....good for me ;-)

Michael

sometimes those rare parts are just around the corner (or laying around in my storage)

 

[65 Cuda 340]

Good GAWD. Just use a good quality timing set with the nine keyways and you don't have to worry about any of this garbage.

Resurrecting this old thread - I'm putting a new cam in my 360. Doesn't have a cam key with it. I think, no problem, I'll just use the one out of the old cam. When I started to put the old key in the new cam, I noticed it's an offset key. I put the old cam in back in 1991. Didn't remember if I had degreed it in or not, but apparently I did.

I looked all through my stash for the rest of the keys that I must have had some time ago. Can't find them.

I have a timing chain set that has three keyways, probably won't need an offset key anyway, but I don't have a stock key, so I reckon I'll just have to break down and buy one.

Grrrrr. . . .

 

[oldkimmer]

The sbc uses two of those keys inline in the crank. Three bolts and a dowel or the cam. Like bbm.

 

[Mopar Sam]

Resurrecting this old thread - I'm putting a new cam in my 360. Doesn't have a cam key with it. I think, no problem, I'll just use the one out of the old cam. When I started to put the old key in the new cam, I noticed it's an offset key. I put the old cam in back in 1991. Didn't remember if I had degreed it in or not, but apparently I did.

I looked all through my stash for the rest of the keys that I must have had some time ago. Can't find them.

I have a timing chain set that has three keyways, probably won't need an offset key anyway, but I don't have a stock key, so I reckon I'll just have to break down and buy one.

Grrrrr. . . .

Just go to any auto machine shop, they should have dozens of them. They buy them in bulk, so should sell you one cheap.