sst45 Crankshaft

[jimi]

The APBA rules for SST45 state "...The crankshaft for the SST45 was prepared for racing by hand grinding a radius on the top crankpin hole....When using a replacement production "fishing " crankshaft it is advisable to duplicate this feature."

https://www.apba.org/sites/all/files/documents/SST%2045%20Reference%20Information022515.pdf

My question is "is this what they mean by the top crankpin hole"?

[kev29p]

Yes. Grind the sharp edge of that hole.

[modifiedoutboard]

radius to eliminate stress concentration , some of the older pre 80 cranks would break when prop would break loose and hook up again.
Cryoing is also a good way to improve mechanical properties and not that expensive.
We cryoed entire rotating assembly and consistently turned over 8,000rpm with no bottom end failures.
Even used OMC rod bolts and stock fishing rods without failure!