Can 3mm be machined from the rod journals safely?

 

Honda crankshafts are Nitrided. The nitriding is less than .010" thick so you would destroy the hardness of the crank by doing that without having it re-nitrided.

 

So if I got the crank "re-nitrided" (assuming it can be done), could I machine 3mm off the crank safely?

 

You are going to be hard-pressed to find a shop that knows how to properly nitride a crankshaft these days, much less actually have the equipment. Also why do you want to take 3mm off the crank? Are you trying to use rods from a different engine? The more material you take off, the weaker the crank is going to be.

 

Well I have a theory that I plan on putting in motion sometime in the future. Basically I want to use F20B rods on an F23 crank. The problem i'm having is that the BE Bore on the F20B rods are 48mm and the BE Bore on the F23 rods are 51mm. A difference of 3mm. So to use the F23 crank, i'm assuming that I can just remove 3mm off the rod journals to make it work, but then that bring up the question, is it safe to remove 3mm off the rod journals? And thats where I got stuck.

 

Why not just bore the F20B rods? If that isn't an option, use aftermarket rods with the right big end bore size.

I had the rod journals on a GSR crank machined at one point, its still running strong. Just a DD motor though, not making much power.

 

What the advantage of the F20B rods? Are they longer?