Another important feature is the factory style full radius counter weights which place balance weight in the correct position relative to the rod pin to insure low harmonic operation across the broadest possible rpm range. Cranks are zero balanced to a 720 gram bob weight which is in the typical range for after market pistons and rods in these engines meaning only minor adjustments will be needed during engine construction.
This crankshaft is constructed from Timken 4340 de-gassed billet steel made in America with all manufacturing done by Crower in San Diego Ca. Finish grinding tolerances are held to .0001 of an inch with perfectly concentric journals with equally perfect journal flatness. Ion nitriding ensures the ultimate in material stability and toughness.
These cranks also incorporate the following design improvments by FRP:
Each rod journal is fed by direct drilling from 2 adjacent main bearings for more consistent supply to highly loaded rod bearings.
Rod and main journal diameters are optimized for proper oil film thickness required in high power applications. Rod pin diameter is 1.8800 and main journal diameter is 2.2811 Main journal diameter allows proper clearance without the need for excessive line honing to gain adequate clearance.
Thrust flange width is increased by .001 for freer running and adequate end play.
Rod flange width is increased by .002 to allow appropriate rod side clearance in most cases without facing the rods.
The crank nose is broached for a 3/16ths woodruff key for driving race style crank dampers used with dry sump oiling systems
Crank can be purchase with or without the factory oil pump drive lever installed.
* Cranks are built to order for each client. Custom strokes are available. Delivery time is 90 to 120 days. These cranks are available exclusively through Four Ring Performance Engineering.
Price is $3100
