JimIII@jdm
Well-Known Member
Interesting. I was led to believe that the cobra jet crankshaft was unhappy (flexed) above 7250-7500rpms. Do you guys do anything additional to the cranks in your shortblocks? Thanks for your input.
There is some crank flex in the higher RPM range and why we recommend anything over 1000 RWHP to use a Billet crank. We use a special coated bearing to help limit the wear from crank flex.
We used the factory Cobra Jet crank since 2008 in all of our Stock Eliminator cars and most of our Super Stock cars which produce between 850-1100 RWHP. Running them for full seasons of NHRA racing where they shift the cars in the 7500 RPM range. About 2 years ago NHRA approved the billet crank and we started using them because it does limit flex.
In a full blown racing application where you are consistently seeing these high RPM's a billet crank should be a must have. But for most of the Shelby population running around 800-1000 RWHP and using their cars on the street, minimal track use, etc...the ocassional 7,000+ RPM shift won't be an issue or promote any premature wear.
JimIII