Eagle 4.250 Cast Crank Broken

[Barry_R]

Cranks - in no particular order

We did this to ourselves. Nobody else to blame.
I tried - hard - to get U.S. suppliers interested in making cast 383 Chevy cranks back in the 90's when I was running the parts side of F-M's performance program. They always claimed that there was not enough volume to do it and turned me down without ever even trying to do a quote. I was stunned - and if they would not do the SBC what are the odds of them doing an FE?

I have run the cast Scat cranks that retail for under 700 bucks in FE engines at documented dyno power levels approaching 800 horsepower, and in five years they have proven to be startlingly durable. Realistically they should probably not be considered for a road race, continuous load application beyond 600 or so - but they are living in that environment better than anybody would imagine.

In FE forged cranks you have a couple options - RPM and Scat. The RPM forged cranks have been around for a few years now. Intuitively they should be stronger than the castings - they are definitely forged. They theoretically retail for around the same price as the Sat castings, but the machining quality is marginal at best, and you need to budget a couple hundred extra to square them up - assume around $900 for one that is truly usable. Probably a modest upgrade. No way to verify actual material - caveat emptor.

The Scat forgings are fairly new to the market, and are decidedly different than the RPM in terms of forging quality, shape, and machining. Costs a couple hundred more, but worth it without question. Probably the best choice for 700+ horsepower and/or mid-level road race use.

At the top of the pile are billet cranks. Most billet cranks are the only FE ones that are domestically made. Scat is the only supplier that does both offshore sourced castings & forgings, and domestic billets. The other billet suppliers include folks like Moldex, Bryant, Crower etc. Billet cranks are what you really want for seriously high power (800+) or professional level road racing applications. You also want to keep at least $2500 or more set aside for one of these.