Camshaft re-grind

[Jason M.]

Pete did a 1007B for me. It was like a piece of jewellery.

[Pete]

Originally Posted by Mike B

I'm curious as CompCams was mentioned, wouldn't they have a CNC machine that if they started with good/original cam, profiled...wouldn't each and every cam come out exactly the same?

I know nothing about cam grinding or variables involved (although I can see that as Pete mentioned if a measured cam was worn, it would not be the same as what it was built from)...but would think if the first program put into the machine was known "as good"...all subsequent ones would be?

Thanks.

If you put good info into a CNC machine you get good stuff out.
Usually only production runs of cams are done on computer managed machines.
I have automatic digital feed and readout on my machine but seldom use it because most of my stuff is one cam at a time and it is faster to do by hand.
As far as worn cams go, when you regrind it, the original lift is restored.
The duration will generally be slightly less and the rate of lift will be slightly more. The lobe will be slightly smaller in diameter than original.

[Ol' Ron]

Gary ,Pete and most people interested in the L-100.
I don't have any doubt that there are many better cams than the L-100, it's an old grind originated in 1952 ny the Literio Bros of Providence RI. The first tine I saw it I told the owner of the engine it wouldn't work in his application. a 5500 ln 1942 Ford Ambulance. I just felt it had too much timing wor the weight. My experience with camshafts came from the track and I tried several of them and finaly settled on the 400jr. At this point we got involved with the suspension and tires which may have helped other engine modifications. But we were limited to 258ci and one carb among other things. Back to the L-100. Needless to say it preformed better than expected and became populra for several reasond. First it worked, the engines run great pull hard and get great mileage, second their Cheep, started at 120 and went to 175 on your core, and last they sound better than the rest,, or as Paul Howard put it "The smiley cam" I run 50 lbs of spring pressure on them, so Iexpect them to last forever.
Now comparing it to other cams just doesn't matter ask one who runs one. and now there gone.

[Pete]

"P.S. The only difference with most cams in the same range is the idle quality/sound, depending on the grind. It's for this reason I disagree (for the most part) with Comp's "Thumper" series. But that's me. "The sound" is and was always important with the Flatties though."

Yea, roger on that. A lot of flathead guys still haven't heard that they can get that "thumper" idle by screwing the idle jets way off and pulling the choke out slightly.
This way you save all that money for a cam and you get the associated poor gas mileage too.

[GOSFAST]

Hi Ron, in my opinion regardless of when the cam was designed, if it was "good" back then it will still be "good" today (on the Flathead platform) and still deliver. That goes without saying.

I have made some serious HP recently (on a few BBC's) with some 40 year old grinds. One recent 396" comes to mind with 10.5:1 C.R. making 510 HP easily with a 1970 "Engle" (flat-tappet) cam. I feel any more recent/new grind in there would have made a negligible difference on the dyno.

Thanks, Gary in N.Y.

P.S. I'm not in the cam grinding business, but years ago I was connected to CMC, which was supplying many of the cam cores for the entire industry, and knew exactly what a core cost. I suspect the price on the Flathead cores is "up-to-the-moon" today. Just a logical guess being a limited-production item. Same for the Nailheads and others. This explains why the cams are relatively expensive today, you're paying for the new blanks.

[JWL]

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I don't understand what aspect of the Comp "Thumper" cam is being disagreed with? Is the idle too radical-salty-rough, or, is the idle too smooth?

One thing accurately stated is the fact there is VERY little peak HP difference in any of the cams within a specified group. Even the "maximum performance race" cams make little peak difference. However, there can be some significant differences on the way up to peak power.

Although the modern cam technology derived from computer aided design programs is less meaningful in a Flathead it is, none the less, useful in achieving good longevity at maximum performance for the desired end use. If I had a choice I would always select a "modern" design. A Flathead cam lobe is actually very radical in design because there is no multiplying factor from a rocker arm.

Most people are happy with their cam choice because they don't have anything to compare with. The fact that a different cam would provide 5-10% more torque in the most often used RPM range doesn't register so long as the "sound" of their cam makes them happy. Hell, I could easily drive a Potvin Eliminator on the street and it is one of the best maximum performance cams ever designed. But, the fact that I could drive it around town does not mean it is a proper choice for doing so.

[KiWinUS]

JWL , PETE . GARY , so help us all out please , if we can not get an L100 what in you guys recommend that is comparable or even better ?
Thanks
Cheers
Tony

[Tim Ayers]

Originally Posted by JWL

I don't understand what aspect of the Comp "Thumper" cam is being disagreed with? Is the idle too radical-salty-rough, or, is the idle too smooth?

One thing accurately stated is the fact there is VERY little peak HP difference in any of the cams within a specified group. Even the "maximum performance race" cams make little peak difference. However, there can be some significant differences on the way up to peak power.

Although the modern cam technology derived from computer aided design programs is less meaningful in a Flathead it is, none the less, useful in achieving good longevity at maximum performance for the desired end use. If I had a choice I would always select a "modern" design. A Flathead cam lobe is actually very radical in design because there is no multiplying factor from a rocker arm.

Most people are happy with their cam choice because they don't have anything to compare with. The fact that a different cam would provide 5-10% more torque in the most often used RPM range doesn't register so long as the "sound" of their cam makes them happy. Hell, I could easily drive a Potvin Eliminator on the street and it is one of the best maximum performance cams ever designed. But, the fact that I could drive it around town does not mean it is a proper choice for doing so.

During my days of parts hunting I've come across quite a few NIB cams. Two of these were ground on new cores. One of these is a Crane Cam from sometime in the '70's. I forget the grind number, but it is a acceration cam (short track grind).

From what I've read about Crane and the box and all of the literature inside the box touts the same is that it was ground using the latest technology and used a computer-aided grinding machine.

This seems to be inline with most of what I read about Crane's quality control.

I guess the purpose of this I'm sure there is a balance between backwoods racers doing a "belly grind" right in the pits during a race or the latest and greatest computer aided grind.

When done right, it should work. I would assume having consistantcy between lobes, angles, ramps etc. would be an advantage with longevity.

Now if I only had the time and money to having enough motors running to compare all of the cams, I'd be a happy and lucky man.

Here is the list that I have:

Original Potvin 3/8th: Ground by Bill Jenks
Crane: 352-2 (I think this is grind #)
Clay Smith: 272-2 & 284-2
Melling A-100: 1/4 mile short track cam
A few others that I can't recall at the moment.

[Ol' Ron]

OK, I was asked what I thought was the best cam for racing? This is a tough one because there are many different kings of racing and I'm only familiar with short track, but if I had to pick a cam out of all the "Stuff" that's out there I'd pick the Sig Erson D-410. Why? In my case, it's the only cam that preformed better than expected. It ran better than all the other cams we'd tried up to that time. However here's the catch. We installed it with out the owner/drivers knowledge. When we started the engine we were disappointed with the SOUND. And almost put the 400jr back into the engine. Very glad we didn't, because there was a noticeable improvement in acceleration off the corners. But that was 40 years ago.

[Pete]

First we will assume a typical naturally aspirated belly button STREET flathead with no port reconfiguration welding.
A 1/4 by 5. (276 ci)
I would pick a 1007B first.
Second would be a 3/8 Potvin.
3rd would be a 6372 Harmon Collins.

For a circle track 315 ci or bigger engine I would go with a 404A or a #4 Offy.

For a standard port configuration Bonneville engine I would use a 6355 Harmon Collins.

For drag racing I would use a 6355 H&C or a 425 Potvin.

[Ol' Ron]

Thanks, I'm gona write that down, I might need that information some day

[KGS]

From a performance and economy standpoint, how and where does the 1077B fit into this mix?

[36-5window]

I had Oregon can grinding do my 430 Lincoln cam, first one went flat.they blamed me for not assing zinc. he did another cam that I provided for 1/2 price. I used the brad penn oil and it is still going great.Just my 2 cents,Henry

[fordcpe]

I have a 8ba cam on my work bench for two years to send away and make a L100 but never sent it.1007b here I come now.Darrell

[Pete]

Originally Posted by KGS

From a performance and economy standpoint, how and where does the 1077B fit into this mix?

See post #30 for performance.
As far as gas mileage goes, I once overheard a famous engine builder tell a customer, "if you want economy, take the bus".
Seriously though, all of these street cams should yield 18 to 20 mpg if you balloon foot it.

[Kahuna]

I do run a Potvin Eliminator on the street. Great cam, gets decent mileage

[KGS]

Originally Posted by Pete

See post #30 for performance.
As far as gas mileage goes, I once overheard a famous engine builder tell a customer, "if you want economy, take the bus".
Seriously though, all of these street cams should yield 18 to 20 mpg if you balloon foot it.

I think that the 1007B in number 30 is different from the 1077B.

[Pete]

Originally Posted by KGS

I think that the 1007B in number 30 is different from the 1077B.

Sorry, I misread that.
I have never heard of the 1077B.

Kahuna,
I have run the 425 in several street engines also. I really like it.

[Ol' Ron]

I think the 1007B is an excellent cam, ran one in the stock car before the 400jr.