Advice please on case hardening camshaft

[mrehmus]

We found the best way to harden cams was to rough out the cam leaving disks for each cam position and bearing. Then harden the steel. Once that is done, check the blank for straightness and adjust if necessary. Then grind the cam and bearings which will insure the cam is straight.
We hardened the cams (made of 3140) by placing the blank in a drill press and spinning it at low RPM while heating it with a torch. When everything was cherry red, it was submerged, still spinning, in brine. This leaves the blank almost straight and at about RV 55 hardness which grinds quite nicely.
Of course you have to have a cam grinder which is no small task to design and build correctly.
This process works so well that virtually everyone in our club (Bay Area Engine Modelers -www.baemclub.com) drives to Dwight Giles shop (he has the grinder) to accomplish this. He and Ken Hurst developed this technique for their V-8s (Challengers and the Black Widow).

 

[Weldsol]

They had no problems with a small order like this? If you don't mind what was the cost? I was thinking of machining the next one out of something hardened and tempered to a machinable state and see how it holds up. Thanks

Hi Basil
send me a PM with your email and I will send you my contact at the company and what it cost me

 

[mayhugh1]

Has anybody used pre-hardened stress proof material? Around 30 on the Rockwell hardness scale, so should wear much longer than mild steel, but not so hard that it cannot be machined (and quite beautifully) with HSS tooling (or carbide, of course). I've never used stress proof for a cam, but have used it a time or two on other products - it really does machine beautifully.

I've used Stressproof for my last several camshafts and plan to use it on my current build. I usually use oil hardening drill rod for the lifters and those I typically harden. - Terry

 

[Charles Lamont]

Keep your tappets. If you decide on an unhardened camshaft, a soft on hard combination should wear less than with both soft. My preference is for a built-up camshaft with hardened silver steel (drill rod) cams Loctited in place.