Why do some SB350 forged cranks sell for about $500.00 and some cost in excess of $1500.00???? :confused:

 

There are 4340 forged and 4130 and 5140, etc.
Not all are the same quality. We sell 4340 Forged steel cranks and the are $699.95. I am in the process of adding the to our Corvette Forum mall. They will be on sale for $675.00 for a week the rest of the month.
Good luck,

 

As 2FST4U mentioned there are a few different alloys available for forged cranks. In addition to the material, the other main differences are country of origin, the amount, quality and type of machining that was done to the crank, as well as the reputation of the manufacturer. Additionally, there are other factors like whether the crank is 'non twist', if the journals were chromed or not, if it was nitrided, etc.

Most of the economy forged cranks won't be of 4340 'non twist', and they won't have as much finishing machine work done to lighten the crank and reduce windage.

Even among the same manufacturer there are significant price differences. Crower for instance, who is the world's largest producer of high performance crankshafts, 6 different types of 4340 NT cranks, ranging $1300 to $2500. The only difference is the amount of crank lightening and profiling. for ultimate strength, you can even get a 4340 billet crank, which is what the NHRA Top fuel guys use.

It does make a difference I think. I have a Crower Billet Ultra-light crank, which is their premium crank. Even though it has a 4.00" stroke, it only weighs 41 lbs, compared to a stock GM cast 3.48" 350 crnak that weighs 58 lbs. The weight savings of 17 lbs from your rotating assembly makes a significant difference in terms of how fast the engine revs and actually increases power and torque output due to reduced internal losses and windage. The good thing about it is that it doesn't reduce the strength of the crank, since the weight savings come from pendulum undercutting the counterweights. Unfortunately, they are on the high side, retailing for around $2600.

Besides Crower, other companies like Callies, Lunati, Bryant, LA Enterprises, Moldex offer excellent cranks as well.


[Modified by Monty, 5:55 PM 9/19/2001]

 

Thank you for all the info!

 

Also, you need to evaluate how "ready" the forged crank is to pop into your motor. Some are somewhat generic, designed for either internally or externally balanced motors. In these cases, they require lots of mallory metal and balancing. Others are almost plug and play...designed for a specific rod, piston, balancer and flywheel combo. Too often, owners spend big bux on a forged crank without carefully selecting a top shop to balance the reciprocating assy.