Cam shaft core materials

[Rick Finsta]

It just occurred to me that you can also potentially have your current cam reground. Fill out the spec sheet on Mike's site - he's super responsive in my experience!

[BBO Omega]

I plan to do that. First I want to check out my lower end. If there is any damage, I will likley upgrade to a 496 Rotataing assembly from RR and Cam requirement will be dictated then.

[pdq67]

I plan to do that. First I want to check out my lower end. If there is any damage, I will likley upgrade to a 496 Rotataing assembly from RR and Cam requirement will be dictated then.

May I ask who, "RR", is?

Thanks,

pdq67

[BBO Omega]

Rocket Racing. They sell a bunvh of new, strong parts for Oldsmobiles. Blocks, Billet Cranks, Cylinder Head / Intake Package, etc.

[la360]

Thanks for your replies Mike, I'm not sure what kind of profile I'm going to run as yet. I may look at doing the blanks and leaving them round for now, and mill the lobes after heat treatment.

[user-23911]

Also, what are some instances where you've seen a core break?

One Friday afternoon, mechanic was just trying to finish off a rebuild of a hotted up SR20VE.
That's essentially the hottest version of a Nissan SR20 , the VE being Nissan's answer to VTEC.
The cams had just come back from being reground (unless they were brand new aftermarket ones, can't remember).


Anyway mr mechanic was just tightening one up at the cam caps and........BANG.
It's now in 2 pieces.


No idea what that one was made from but guessing very hard and very brittle and the cam caps should always be tightened up evenly and a bit at a time.

[la360]

Has any testing been done with steels like H13 and D2 tool steel?

[CamKing]

I may look at doing the blanks and leaving them round for now, and mill the lobes after heat treatment.

Then you would have to go with a tool steel, that can be tru-hardened. It'll much slower to machine, and slower to grind.

[la360]

What kind of rockwell hardness is sought? I know some tool steels will go to the 60-62 Hrc range, not sure about case hardened 8620 though.

Thanks in advance

[CamKing]

What kind of rockwell hardness is sought? I know some tool steels will go to the 60-62 Hrc range, not sure about case hardened 8620 though.

Thanks in advance

We carborize the 8620 to 60-62rc, .100" deep

[CamKing]

BTW, if you're going to make cores, you should check with the company that's going to grind them, and ask them about materials.
We charge twice as much to grind the tool steel cams, and they require a special grinding wheel, that many cam grinding companies may not have on the shelf.