High Rpm Pulley Upgrade

[Otto]

For High Rpm engines this is a useful Mod. to keep the pulley from shearing the pins.

[ChrisBennet]

Thanks Otto!
-Chris

[Wayne 962]

Good addition. Jerry Woods mentioned that they had some problems with that happening on some pulleys...

-Wayne

[ikoiko]

What's the approximate cost for the mod.?

[Wayne 962]

Hmm, I don't know - a shop would have to drill both the pulley and crank and have them indexed together - not something you would want to attempt at home. I would suspect that this would not be easily without a jig...

-Wayne

[5axis]

Wayne. That would be more than a home fix, but far from difficult. It's just a 3 hole bolt pattern. Pick up the circumference of the part, set X0 Y0 and then pick up the existing hole to find the exact radius and then trig out the 120's. For the actual machining to hold both size and location the steps should be as follows. 1) center drill 2) drill 3) bore 4) ream to size . It does require some knowledge and skill plus some time to do it well. Fixturing the crank might take some creativity too.
One thought that did cross my mind would be to make a offset pin so that the orientation is a no brainer for assembly.
Just some thoughts from a toolie..
david