[swerve]

Just looking for some opinions on using a GM 6223 Forged Crank or stepping up for an Eagle ESP Forged 4340 Crankshaft for my 427 BBC.

What are the main advantages for using the Eagle crank? Will the GM crank survive just as well?

It will be going into a Merlin III block with the World oval port heads and looking for around 450HP. The car will be a street car and MAYBE a few passes at the strip, but realistically keeping below 5500 rpm.

The write up on JEG'S site says this about the Eagle crank:

They are stress relieved and shot peened for durability and longevity. During the machining process, the crank is indexed for correct stroke and all of the rod & main journals receive a .125'' radius in the corners for increased strength. The journals are then precision ground & micro-polished to an R.A. of less than 5 and Nitrided for superior wear resistance. All of the oiling holes are cross drilled & chamfered for improved oiling to the rods and mains. Counterweights are designed for easy balancing and do not require any machining for block clearance. Each ''ESP'' crankshaft is inspected for dimension, size and stroke accuracy so you know it is capable of going from the box to your block without worries. Eagle also guarantees a target bobweight +/-2% that reduces balancing time.

NOTE: Chamfered bearings are required to provide adequate clearance for the .125'' journal radius.

How much of that do I need to be concerned about if I use the 6223 crank since I'll be getting it all balanced anyway? Also, what is the GM crank lacking besides the radiused journals?

Thanks!

John

[Bryce]

you dont need any of that crap if your planning on only 450 Hp you can do that with a stock block and stock cast crank and most if not all stock heads when ported with a decent cam
you are wasting your money on high dollar parts you dont need
use that crank use a stock 454 block get the world heads and a decent cam and stall can you will have surpassed your goal of power and spent much less money

[bracketeer]

The only time I use a forged crank is when I'm using a tranny brake.

[k-star]

Originally Posted by Bryce

you dont need any of that crap if your planning on only 450 Hp you can do that with a stock block and stock cast crank and most if not all stock heads when ported with a decent cam
you are wasting your money on high dollar parts you dont need
use that crank use a stock 454 block get the world heads and a decent cam and stall can you will have surpassed your goal of power and spent much less money

I gotta agree..... If you are only looking at 450 hp out of a bbchevy the cast crank would work fine... But if you have a steel crank for it use it, don't go out and buy a aftermarket crank, you really do not need it at this level.....

keith

[TurboS10]

Just going to ditto. You are buying parts for a 800-900HP engine and building half that.

Chris

[swerve]

Thanks for the responses!

I picked up a NOS GM 6223 crank and will go with that. I sold a 402 BB just recently that had a forged crank in it but it needed to be dressed.