Guide to Regrinding Camshafts

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72DMag

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Please do not respond call your camshaft company!! That is not the intent of this post. The goal is to give some prior knowledge of what can be achieved with a camshaft regrind before calling the cam company.

The way the world is going, being a small hoarder and having stock camshafts on the shelf may come in handy. Camshaft shortages are getting ridiculous to say the least. Does anyone have a link that goes into detail about camshaft regrinds? If not can we start a detailed thread here? Below are some of the things I've been wondering about with the stock mopar cams and a regrind:

1. If I know the lift of the cam what is the max lift a regrind can give? (Same goes for duration)
2. If a hydraulic flat tappet cam is reground, can it be grinded to utilize roller lifters? (For example, to put an LA cam in a magnum engine and use the eccentric pump)
3. LSA. I assume this can not be adjusted and is built into the cam. Or can 1 degree of LSA change be achieved with a regrind?
4. Convert hydraulic camshafts to utilize solid lifters? (I'm assuming no to this as well)

Any other questions?
 
1. You increase lift by decreasing the base circle. So you are lift limited by what size the base circle and lobe are now and how much of the base circle you can remove. I do not know how small on base circle you can go.

2. Maybe. The lobes on the cam are cast at the foundry. A roller lobe usually has more area under the curve so you may not be able to get a roller lobe on a HFT or SFT core if the material isn’t there.

3. You can move the LSA about 1 degree each way. Maybe 2 if you are lucky. As I said, the lobes are cast at the foundry and you don’t always have enough material there to move the LSA much.

4. If you mean HFT to SFT lobes then yes.
 
According to Ken at Oregon, it's a no go on flat tappet to roller. Only half the flat tappet lobe runs underneath a roller. Some companies are doing it, but failures are high. On regrinds of stock LA hydraulic rollers, some profiles allow up to .320 lobe lift and others allow up to near .340 lobe lift. Hydraulic flat tappets can be reground into solid flat tappets, but most solid rollers are going to require a billet core due to spring pressures required in solid roller profiles.
 
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I’ve emailed Ken today about a pair of hydraulic rollers. One is a 1990 LA 318 .257/.257 lobe lift and a 1987 318 .278 I /.260 E lobe lift. I’ve inquired if either cam will accept grind number 722, which is 222/[email protected], 277/[email protected], and .309/.320 lobe lift. It comes on a 112 LSA, but Ken says you’re limited by plus or minus one or two degree degrees of what the factory LSA is. Stock LA truck cams are 106 to 111 LSA and the car cams are 114 to 116. I’ll opt for the narrowest LSA possible.
 
Garrett Ellison said:
According to Ken at Oregon, it's a no go on flat tappet to roller. Only half the flat tappet lobe runs underneath a roller. Some companies are doing it, but failures are high. On regrinds of stock LA hydraulic rollers, some profiles allow up to .320 lobe lift and others allow up to near .340 lobe lift. Hydraulic flat tappets can be reground into solid flat tappets, but most solid rollers are going to require a billet core due to spring pressures required in solid roller profiles.
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Ken and I have talked at length about grinding me a solid roller from a stock slant 6 core. He said he really doesn't recommend it, BUT that if I kept lift in the mod .500 range so I could run a spring that wasn't too aggressive, it would probably be ok. He said he'd do it but of course it was my baby if something went wrong. Fair enough.

There's one of the guys on the slant6.org site that's had Ken grind him at least one like that and has had good luck with it. Race only, so no extended idle. So yes it can be done, Ken will do it, but be warned, since it's uncharted territory, it's all yours. lol

I'd also like to add that I've seen a lot of people say "you cannot change the camshaft LSA" but that's not true. The real answer is "it depends". I had Ken grind my 331 Hemi camshaft from a stock hydraulic to a small solid. He went from a 111 LSA to a 106. That's a huge jump. But, the camshaft looks a lot like a cheater cam from the 60s and 70s, as the base circle is almost even with the camshaft core. lol Ken said as long as I got correct length pushrods, which I did, It would work fine.

Ken has also told me that Chrysler cam cores are hardened way in, almost to the core, so re-heat treating is not necessary for them.

I have several stock slant 6 cores and am holding on to them. The last cam Ken ground for me, he wanted me to send in a core, but I paid the core charge and kept my core.
 
All I know is that whenever I run flat-tappet cams, they grind themselves.
 
jos51700 said:
All I know is that whenever I run flat-tappet cams, they grind themselves.
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That’s why I’m going to run a factory hydraulic roller setup whenever it’s an option for me. Not been able to graduate to a solid roller yet. I still like solid flat tappets, though.
 
If you think your hoarding a gold mine for the future, then your not. The cores will become available again..
Going to a smaller grind opens up more options than trying to go to a larger grind.. obviously..
So if you had a bunch of whopping big drag grinds then your in a much better place than having a bunch of sub 200@50 stock grinds..
 
Nothing wrong with a regrind if the core hardening is ok.
 
Thanks for all the info Fellas!! So it unfortunately sounds like there isn't an equation one can use to determine what they can get out of their cam cores. It really comes down to what the cam grinder can do or is willing to do as Rusty said.
 
@Bakerlite

This administration still has 2 more years. So don't expect an abundance of cores before that. Not sitting on gold mine. But I am sitting on a way to get engines built while others sit and wait for China cores
 
Everyone everywhere has had interruptions. If you think it's just you , then your out of step with what's happened.
Here's a post from a US cam supplier: This post is now over a year old, and as far as I know most of the restrictions have lifted by now..

"It's crazy.
I only deal with U.S. suppliers, so I don't know how the import inventory is doing.
There's 3 major Cam Core suppliers in the US. All their manufacturing facilities were closed down for 6+ months, and all are having issues, getting employees to come back to work.
While they weren't manufacturing, they were selling what inventory they had.
All the cam companies bought up what they could, but had to use most of their inventory.
With the cam core manufacturers inventory depleted, and the cam companies inventory depleted, the core manufacturers are having a hard time keeping up with their orders, and being short staffed isn't helping.
I have cam cores that have been on order, for almost a year.
I've sold almost all of our HARDKORE Tool Steel cores, because they were only available option.

As for flat tappet lifters, it's about the same.
I only sell US made lifters, and the largest manufacturer on flat tappet lifters in the US, was closed for months. While they were closed, the U.S. foundry that made the lifter blanks, went out of business. This meant the lifter manufacturer had to find a new U.S. foundry, and pay to have all new tooling made for each part#. This about doubled the cost of the lifters.
The supply for .842" lifters is getting much better, but .875" and .904" are still taking months to get."
 
Just as a side note, on the old large 4 cyl road bikes, KZ1000 etc, they used to weld and regrind the cams for performance applications before cores became common place.
 
Bakerlite said:
Just as a side note, on the old large 4 cyl road bikes, KZ1000 etc, they used to weld and regrind the cams for performance applications before cores became common place.
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Tighe cams in Brisbane will still do this, not sure what they charge for it though. but this would open up a lot more options for the regrind.

On the cam cores - I spoke to a guy at Howards cams a few months ago and he told me a similar story - labour shortage at the foundry who casts their cores so they couldn't keep up with the demand. Having said that they told me 3-4 months wait on my SFT and it was at my door here in Australia 9 weeks later.
 
Bakerlite said:
If you think your hoarding a gold mine for the future, then your not. The cores will become available again..
Going to a smaller grind opens up more options than trying to go to a larger grind.. obviously..
So if you had a bunch of whopping big drag grinds then your in a much better place than having a bunch of sub 200@50 stock grinds..
Click to expand...
No they're not WORTH anything, but in my case with the slant 6, there's been a shortage before everything else, because people just throw them away.
 
Poor old slant! It's just not right I tell you!!!!
Weld up regrind if things get tough..
 
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