Cam re-grind info

[prairiehotrodder]

How does a cam regrind work? Does the base circle get smaller thus requiring longer pushrods ? How do you know if a new grind will fit over an old grind? Is it even worth it? Compared to buying a new cam? Can you send any brand of cam to any cam company for regrind? Do all cam companies do it? Who does it for the best price? I have a Lunati BBC solid roller that has some scatches along one side of the roller track. It works fine but is tough to sell. A friend has a comp solid roller (over .800 lift) that has a damaged lobe from a failed lifter. I've been thinking about getting them reground. Any advice out there?
Brian

[DaveMcLain]

Yes the base circle does get smaller and that's why when regrinding it is always best to grind to a larger not smaller cam. This takes little to nothing off of the nose and most all of the material off of the base circle and flanks of the lobe. Really it is possible that the reground cam could turn out to be nearly identical to a new cam of the same specifications. Also some cores can take a regrind better than others. Factory Ford roller cores for example are excellent quality and great to use for regrinds to make them into a performance cam.

Some cam grinders are much better and doing regrinds than others.

[panic]

I made some comments on my site here: http://victorylibrary.com/mopar/regrind.htm

[CamKing]

If you're looking at regrinding them, so you can sell them, it's not worth it.
If you're looking to regrind them into something you can use, it's an inexpensive way to try a different cam.

[Walter R. Malik]

As long as the lobe placement on the core with separation being near the same it can easily be done; especially if the lobe profile being ground is very near what is already there.
A lot of larger camshaft companies who do re-grinds don't like to do them. They would prefer to sell you an entirely new camshaft so, the wait time for it to get done by them often will sometimes be weeks. Other companies will get them finished as soon as they can.

The original Ford Motor Company hydraulic roller cores, as Dave has mentioned, are often hardened over .140" deep and some other aftermarket cores are merely .050" deep in places so, that plays into it all, also.

[prairiehotrodder]

they would not be for selling. They would give me a chance to have different grinds ready for the future changes to my engine.

[DaveMcLain]

they would not be for selling. They would give me a chance to have different grinds ready for the future changes to my engine.

That sounds like a great plan.. I've done regrinds on otherwise mostly useless cams many times especially for testing out ideas. I have an old flat tappet cam here that says Lunati on one end and Reed on the other its all f&#ked up!

A few years ago I had a guy bring in a bunch of parts for a big Ford that he wanted me to build for his mud racing effort. He wanted a 557 and in his stuff was a brand new solid roller cam that was way too small for the application so I had it reground to something appropriate and its performed well.

[1972ho]

What is the most that the old nascar tool steel through harden flat tappet cams can be reground to.

[prairiehotrodder]

the economics of it is what i need to learn. I recently bought a brand new ERSON solid roller for $300 plus freight. By the time i ship my 2 cams somewhere, then pay for re-grind then ship back to me ? I guess i'll have to call some companies.

[PackardV8]

How do you know if a new grind will fit over an old grind?

What is the most that the old nascar tool steel through harden flat tappet cams can be reground to.

Both questions are too vague. Short answer is, "You can't grind air." Older cores, whether OEM, aftermarket, or already a regrind, tend to have a limited possibility of how much lift and/or duration may be extended.

The Studebaker V8 has a small cam core and very quickly runs out of heel material when adding lift. Then, the core has to be machined smaller between lobes.

More recent cams for more recent engines will usually have sufficient material to increase lift and duration as needed.

Does the base circle get smaller thus requiring longer pushrods ?

Yes, No, Maybe. Some engines with non-adjustable valve train can get into trouble with a simple valve grind and stock cam regrind.

the economics of it is what i need to learn. I recently bought a brand new ERSON solid roller for $300 plus freight. By the time i ship my 2 cams somewhere, then pay for re-grind then ship back to me ? I guess i'll have to call some companies.

Speed costs money. How fast can you afford to go?

FWIW, If you're considering a custom/non-catalog grind, put the specs in writing and get a written quote back confirming the cam company will provide exactly that. It's not unheard-of for a cam grinder to just look at your RFQ and choose the closest master they've got on the rack and figure most of us don't have the skill/talent/ability/patience to degree wheel and graph what they actually sent.

[BlitzA64]

I've had a couple roller cams done, both started to fail rollers compressing the lobe on the flank. I guess after the grind the hardening wasn't deep enough

[prairiehotrodder]

i found out Erson charges $125 for a re-grind. Seems like a decent price. On a billet roller cam wouldn't it be the same hardness all the way through ?

[DaveMcLain]

i found out Erson charges $125 for a re-grind. Seems like a decent price. On a billet roller cam wouldn't it be the same hardness all the way through ?

No they are only surface hardened and only hardened on the lobes. The core of the cam is left soft otherwise it would break.

[rustbucket79]

Interior cam supply in Salmon Arm, BC has a fair library of solid roller lobes and their regrind price isn't bad, plus you don't deal with borders and currency exchange.

FWIW I've had one instance on a solid roller regrind where the opening flanks of a the lobes showed wear very early on, so I think it's reasonable to be concerned you might grind through the hardening if you alter the profile excessively.

[1972ho]

Does anybody know about the through harding process,all that I have heard is some of the tool steel camshafts are hard all the way through to the core.So I would figure if that is the case then shouldn’t they be able regrind cam like this to greater than 4 degrees and .020 lift and change lobe separation.But I keep being told that they can’t be reground to much more than any other cam.Like I have this nascar tool steel through harden flat tappet cam that is 55 mm journal ford Windsor style the cam has 281 intake duration and 288 exhaust at .050 and I wanted it reground to a cleveland base circle and journal size and reduce the duration to 252 int 264 exh at .050.But I have contacted at 5 or 6 cam companies and they keep saying it will be ground to far below the Harding of the through harden core.