Material for Rocker Shafts

[Alex Westling]

I am making a set of roller rockers for my car as a spare time project. Not looking to sell them or any thing so cost is not an issue I just want to do it right. My question is what my material of choice should be for the shafts. I was looking at some of the rocker manufactures websites and noticed either 4340 or 8620 steel was used. What is the difference between these two steels.

I know 4340 can be threw hardend and 8620 is case hardened. What will be better as far as stregth/wear. The shafts will have needle bearings riding on them.

I also heard H13 tool steel is suppose to have a high shear strength at high operating temps. I am not sure of the cost on this stuff but it could be a option as well. Thanks for the help.

[Geof]

You have been around for a year or so, have you seen any posts by NC Cams? He seems to be absent lately but he would be the one to give you the definite answer; maybe find his signature some place and send a PM. And I hope he doesn't object to a suggestion like this.

[Alex Westling]

Yup. I was hoping he would show up. I will wait a bit before I bug him with a PM. Meanwhile does anyone else have any suggestions?

[RICHARD ZASTROW]

Are you going to have the needle bearings running directly on the shaft? If so, check the hardness required for the needles to run on and lube requirements. Like Hu suggested, I,d PM NC Cams, just don,t ask for cam grinding "trade secrets". lol

Dick Z

[Geof]

Originally Posted by RICHARD ZASTROW .... Like Hu suggested, I,d PM NC Cams, just don,t ask for cam grinding "trade secrets". lol Dick Z

Whadda ya mean "like Hu"???????????

Mind you if that was a slip of the mind that indicates who and what are connected to who and what in your memory I am extremely complimented.

[RICHARD ZASTROW]

Geof, Sorry 'bout that. Just confused while associating great minds in a common file. lol

Dick Z