Question for the builders out there. What mods have you performed to the crank for NA power. i know most people micro polish the crank but what about the nitride coating. From what i understand its only about a .001" think. So i guess if ya go too deep your done? Any input?

Also, what about knife egded cranks. I know it reduces the rotating mass and helps cut through the "air"/ "oil". What about its effect on overall strength?

Please post your thoughts as well as suggestions. Building a sleeved 2.0L if it helps.

 

knife-edging the crank will weaken it, but it will be notable in acceleration of the engine. Ideally counterbalancing after removing material fro the crank is the safest approach.

Micropolishing is something the machinist does anyway when getting the assembly balanced.

What is the purpose of nitride coating ???


Greg

 

If you're saying that there's a nitride coating on the journals fo teh crank, then I'll tell you that there is none.

You can reforge (is that the right term to use?) the crank by using a reheating process to straighten out the crank and make sure the crank throws are all in-phase and straight.

You can also stress-relieve the crank by polishing and shotpeening.

THese processes are almost never necessary b/c the cranks are good enough as is.