What are the pros and cons of reground cams. Trying to find a mild performance for my 303. Clay Smith said they can regrind mine, they have no blanks to grind a new one.
I've wondered how the cam grinders go about regrinding a cam. Do they build up material on the lobes and then grind the new profile? Or do they decrease the diameter of the base circle and then grind a new profile relative to that circle?
Pete1 on the HAMB just did an Isky E-3 clone for my 324. My deal is 100% period, and I wanted a period cam. I haven't degreed it yet, but his reputation for quality is very good, and it looks great. He was incredibly fast and efficient, tracking said he got the cam on Thursday, he ground it on Friday, mailed it out the following Monday, and I had it in my hands 1 week later, that includes clearing Canadian customs. They decrease the base circle.
Normally the base circle is reduced the amount the lift is increased. on some cams some grinders will add material to the lobes. But that will result in a cam that is no longer straight. And that will take time to straighten. Time is money, so that becomes an expensive cam. Dema Elgin has reground several cams for me. I also had Crower regrind a pair of cams for a DOHC engine for me that I was quite happy with.
Pros, you get a new cam profile, on an OEM base, at low cost. I don't know of any cons if you get a quality regrind from a good supplier. Pros of a new cam, you get a new cam. Quality depends on the supplier but expect to pay more unless it is for a Chev small block V8. In either case you will need new lifters.
Just about all my stock cars had a custom Chet Herbert grind cam in them. AFAIK, they were all re-grinds. I still have a Duntov circle track grind in the box on the shelf I got from him in 1983.
I'm wondering if a used cam may be more brittle from use . Also what do they do about dist drive gear. If re ground would I need another set of pushrods for hyd lifters Posted using the Full Custom H.A.M.B. App!
You would start with a cam that has a good drive gear. Normally the buyer supplies the cam that is to be reground. There is no "Brittleness" problem. Depending on how much you wanted your lift raised and the amount of travel in your lifter, You could need a longer pushrod. I did not.
As above...Delta Cams in Tacoma.. Great customer service. Sent from the east coast round trip, 8 days. They were the first and only cam grinder I could find that had ever heard of my engine and had reground them before. (Willys F-head 161) Very reasonable price. I'd certainly use them again.
You should probably send me that cam you'll never use it. LOL @RichFox pretty much nailed it, the most basic way to regrind a cam is to knock some material off the heel of the cam ay least that is the starting place, you adjust your valves on the heal of the cam so when the heal is closer to the center and the nose is in the same place it leaves you with more lift. After that the rams have to be adjusted to go with the new profile and sometimes they will play with the nose of the cam a little to change the duration. I don't see an real down side to doing it that way, unless you wanted something like a tighter lobe separation or the like. if you had a soft cam to start with then you would have a bad cam but it was already bad wasn't it.
Depending on who you buy a new cam from, the old core is probably far better than the new cam you just bought. And benno nailed it, the biggest problem with re-grinds is, depending on what profile you are grinding, it can be tough to move the LSA much.
Isky used to Hardface cams by grinding a groove and filling it by welding with hypereutectic welding rod. It is possible to build up the lobes by welding but of course, this costs money.
The original cam cores where not that great to begin with for an early Olds..... A regrind will be into even softer material...... We use nothing but new blanks for ours
I'll dig it out and see if it has a spec sheet with it. Not a great cam for what I'm doing these days.
You always run the risk of having a bad core, GM had a bunch of them again a couple of decades back (not that we would be using newer cams to regrind). I think the only way anyone would ever know is chatting with guys like us who have been playing in the industry for a while, its not something that they broadcast.
On gm aftermarket cams the Ep1 cores are inferior to the p55 and k15 cores. Theres been some real junk sold in the last few years by "reputable" cam co's. Doesn't really apply to regrinding or olds rockets, but since we are wandering off...
Falcon George, I'm wondering why you didn't bring your cam to the well known old time cam grinder in Vancouver... I had a cam and lifters done there years ago and they seemed fine.
http://www.deltacam.com/camshaftgrinding.php?p=3 Check out the videos at Delta Cams, very informative.
What you get when you grind a soft core cams cranks or whatever is pitting and what appears to be chatter marks. Not really chatter marks at all just bad places in the core. Anyone who works with any type of machining process, grinding, cutting, drilling and etc. will tell you that your work can be no better then the martial that you are working with. If you are working with an inferior core or blank you are not going to get an acceptable result. I have even seen it with simple work like rotors and drums, you are working along, perfect surfacing and babam a pit or a hole. A minor pit in a brake rotor is no big deal, but a minor pit or several in a cam shaft can be catastrophic. OK I am the one that took it off the rails, sorry bout that.
shipping a cam in a cardboard box will result in a bent cam as well. The cam grinder can straighten it, but on a finished cam, straightening will always impart some base circle runout, which will affect idle quality, among other things. Pics on how I ship mine.
LOL I have never bough a new cam that didn't come in a card board box. Good idea on the shipping container.
Some companies have FINALLY started shipping them in those ABS boxes. Most every cam I have ever bought prior to that was tweaked. I usually take them into Shadbolts, and he straightens them for me, but they are never as good as if they didn't get bent in the first place.
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