Camshaft: New vs Regrind

[Shoebox]

I'm asking this to generate comments from the many very knowledgeable folks on the Barn. I want another Isky 1007b cam and I have a nice used 8cm cam to use for a regrind, and Isky has told me no problem to grind me a new one on a new billet, even it's no longer one of their catalog cams. The price is about double, regrind vs new. Aside from price, what are you're comments about this? My current engine build has a 1007b regrind by PETE, and all looks good, however the adjuster bolts on the Johnson lifters are farther out than I'm used to seeing due to the smaller base circle. I am really open to any comments and suggestions. Thanks.

[40cpe]

Chevrolet valves are 100 thousandths longer than a Ford valve. Use them on a regrind so the lifter won't be extended so much.

[tubman]

If the 8CM is in good shape, I'd save it for someone building a mild engine for a heavy car. I have one in my '51 Ford club coupe and really like it.

[38 coupe]

I would rather have an 8CM cam with no wear than a 1007b cam.

[flatford8]

I agree with the 8CM comments…..but, aren’t there lash cap’s available so you can use the cam you want?………Mark

[Shoebox]

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Originally Posted by 38 coupe

I would rather have an 8CM cam with no wear than a 1007b cam.

Well opinions vary, however I don't have an 8CM with no wear.

[Shoebox]

Originally Posted by tubman

If the 8CM is in good shape, I'd save it for someone building a mild engine for a heavy car. I have one in my '51 Ford club coupe and really like it.

Good point.

[Ronnieroadster]

A couple of things i consider when it comes to using a stock cam for a regrind first I measure the cam bearing journal diameters. The dimension of each journal should not measure under 1.7955 . Once I know all three journals measure correctly now the cam can be reground. When Pete was doing the grind he was always spot on when it came to the cam timing that's the intake center line degrees. Getting a regrind that perfect is not easy. However recently I had a good used cam core reground by Snider in San Diego using a Potvin profile. Checking the cam timing the Snider cam timing was as advertised.

What I have experienced using a new cam from Isky one that's ground on a new core what they call billet. The cam timing was way off the advertised specifications on the timing card. What should have been 112 degree intake C/L it was actually 116. In other words the cam was so far off the engine would not perform very well.

While its not easy to check cam timing the effort is well worth it to at least to determine if the cam is ground as advertised. Now correcting the cam timing location is rather difficult on a flathead to actually do since it a bolt on gear this bolt pattern needs to moved to correct the problem.

So overall what ever you decide to do be it a regrind or having Isky do it on a new core checking the cam timing is the only way to be sure its actually correct. Another point about that cam gear bolt pattern one would think the four 5/16 cam bolt holes are actually 5/16 diameter holes. That's not the case check the bolt holes in your cam gear you will find two holes and sometimes three holes are actually over size. The cam torque is not being transferred using all four holes.

Each cam gear I have checked be it an original Ford aluminum or fiber gear as well every replacement gear sold on the market including NOS French cam gears all have these oversize holes. I may have added more to the original posted question but heck just thought this information will be helpful for some.
Ronnieroadster

[Tim Ayers]

Good stuff, Ronnie. Curious on your thoughts of using an early cam with the pressed on gear? I found a good early core (just measured the cam journals, LOL) and a NOS press on aluminum gear. Recalling the issue you mentioned above with my Potvin cam.

Have you found that the slip on gear remains true or in place or does it eventually move? Would using a Locktite product help? Is there a way to pin it once set on the nose of the cam?

[Shoebox]

"I may have added more to the original posted question but heck just thought this information will be helpful for some."
Ronnieroadster



Ronnie,
ALL of your posts contain gems of information! Now I need to measure some cam journals and cam gear bolt holes. The issue of correct cam timing is a new issue (for me) to be aware of, whether a regrind or new. One wonders if the Isky cam you found to be off,...was it a fluke or have they gotten sloppy, who knows? Glad I'm not in a rush for a cam.

[GB SISSON]

Originally Posted by Shoebox

I'm asking this to generate comments from the many very knowledgeable folks on the Barn. I want another Isky 1007b cam and I have a nice used 8cm cam to use for a regrind, and Isky has told me no problem to grind me a new one on a new billet, even it's no longer one of their catalog cams. The price is about double, regrind vs new. Aside from price, what are you're comments about this? My current engine build has a 1007b regrind by PETE, and all looks good, however the adjuster bolts on the Johnson lifters are farther out than I'm used to seeing due to the smaller base circle. I am really open to any comments and suggestions. Thanks.

While certainly no engine expert I have given considerable thought to keeping valve lash secure with our available adjustable lifters. I think that having extra threads showing on the lifters is a good sign that you may be able to install a jamb nut on that bolt, ending all worry about your lash staying put. Just a thought from the peanut gallery.

[Bored&Stroked]

I would have no problem having a regrind done on a good original core - as long as the journals are in spec. Also, you can have the journals ground to .010 - and cam bearings are available.

Side Note: Every original Potvin 425 cam that I've seen was ground on a 32 Billet core and the journals were ground to .010 . . .

Cam Timing: Keep in mind that it isn't just about the intake centerline (think advanced/retarded), it is also about the accuracy of the actual lobe profile as well as the lobe separation. You cannot change either of those with a timing gear mod, so accuracy of the grind is very important. I've seen cams where the lobe separation or timing events were way off (one, the other . . . or both) - making the cam a piece of junk for me.

Pete's work was fantastic and his equipment is now at Salt City Speed Shop. He trained them and they can now regrind cams. I would consider giving them a call.

https://www.saltcityspeedshop.net/

The 1007B is a GREAT cam for a smaller cubic inch engine . . . say up to about a 276 or so. Pete is a big fan of this grind - so am I!

Best of luck gang . . . keep em' running!
B&S

[Ronnieroadster]

Originally Posted by Tim Ayers

Good stuff, Ronnie. Curious on your thoughts of using an early cam with the pressed on gear? I found a good early core (just measured the cam journals, LOL) and a NOS press on aluminum gear. Recalling the issue you mentioned above with my Potvin cam.

Have you found that the slip on gear remains true or in place or does it eventually move? Would using a Locktite product help? Is there a way to pin it once set on the nose of the cam?

Hi Tim
I personally have never used the press on gear but if I ever decided to do it I would simply pin the gear. If you decide to go that route I have a few NOS early cams all with the original Ford fiber gear. Replacing the fiber gear with the NOS aluminum gear would be a good combination. Delivery to Hershey would be easy
Pete always preferred the press on gear design so its certainly a good possibility.
As mentioned above it may not only be about the cam timing C/L. However any after market cam sold always includes the words check the cam. These instructions guide the user to verifying the C/L.
Ronnieroadster

[S.Duncan]

Hi Ronnie,I know you've used roller lifters in some of your ardun builds,what do you think of a reground steel 32 cam for rollers in an ardun?

[Ronnieroadster]

Originally Posted by S.Duncan

Hi Ronnie,I know you've used roller lifters in some of your ardun builds,what do you think of a reground steel 32 cam for rollers in an ardun?

Steel roller cams are heat treated so i don't think the Ford 1932 steel cam would survive. Any 32 cams i have seen all of them needed to be ground .010 under on the bearing journals. The roller lobe shape is so different I doubt there would be enough material to grind into the profile needed to get a decent amount of lobe lift. I have an original 32 Ford steel cam ground by Isky for an ARDUN using the stock lifters. The bearing journals are .010 under so the actual lobe lift is not great. With the stock rocker ratio added into the figures the valve lift is under 400
I know there's economy cast roller cams offered by Comp Cams and others i have personal seen a cast roller cam fail. So overall a good new steel roller cam is the best way to go.
Ronnieroadster

[Bored&Stroked]

Originally Posted by S.Duncan

Hi Ronnie,I know you've used roller lifters in some of your ardun builds,what do you think of a reground steel 32 cam for rollers in an ardun?

What Ronnie said.

To add -> roller cam blanks are usually made from 8620 AQ/BQ bar stock and have two grind operations.

1) Once the lobe and journal locations are cut into the core, then it is copper plated
2) The first grind process roughs in the lobes and journals - leaving about .030 of material. This also removed the copper plating from these areas. The roughed in core is now heat treated and the heat treating only goes into the areas where the copper plating was ground off. You don't want the whole core heat treated, just the journal and lobe surfaces.
3) Then the cam is finish ground to remove the last .030 or so and finish the journals and lobe profiles.

I've had Potvin 425 profiles ground on original 32 cores - this is the way that Chuck Potvin did it. With the light spring pressure of a flat tappet profile and the fact that the lobe profile would "fit" into the stock lobe profile, this worked just fine.

Roller cams have heavy lifters and sometimes very aggressive profiles (think inverse radius grinds) - they take a lot more spring pressure - both on the seat and fully open. This is why you want a steel billet core for a roller cam.

Enough out of me!
B&S

[Shoebox]

Just a little follow up on this thread, recently Mike at H&H told me that he uses reground cams in 99% of his engine builds. This says something,.. just not sure what. He is an Isky dealer.

[tubman]

Basically, that there are no new blanks to be had. I've read this a few times lately in different places.

[Tim Ayers]

Originally Posted by Shoebox

Just a little follow up on this thread, recently Mike at H&H told me that he uses reground cams in 99% of his engine builds. This says something,.. just not sure what. He is an Isky dealer.

For most grinds, a reground stock cam will work out fine. What Dale and Ronnie mentioned are some very specific cams that you will not be using. Price out a set of roller lifters from Crower and I think you'll think twice about a roller for a street build. LOL!

Most common performance cam profiles can be done on a stock core. I'd say MOST grinds .400" lift and under.

There are certainly odd ball grinds out there that may not (mushroom or radius lifter grinds) but for what you are looking to do (1007B, Kiwi100, etc), you'll be fine with a stock cam reground.

[John R]

Very good info in this thread. Would like to see some expert comments on the viability, pro/con of using either Chevy valves or lash caps if using the thin-headed adjustable lifters.