revelation about comp cams shelf cam grinds

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revelation about comp cams shelf cam grinds

Post  ChrisH on June 15th 2016, 10:55 pm

i just noticed this, but I happened to be looking at Cleveland cam grinds to get an idea about a motor for a friend. I happened to look at the Magnum 282S cam for a Cleveland and realized it was the same cam as the 282S for a 429. I checked the FE version and 302 version and yes its the same grind.

then I thought surely it isn't the same for a chevy small block. it is the same grind. I checked 7 different motors and the magnum 282S cam is the same cam no matter the motor.

302, 351, 428, 427, 429, 460, 350, 354 apparently all require the same cam dynamics. I would have never dreamed that a major cam company would have put so little R&D into cam optimization for respective motors.

I don't know how pervasive this is through their catalog, but it is sure eye opening.

one note:
when I say they are the same I mean the cam card is the same. ramp rates could vary but cam lobe is not noted, just timing numbers and lift.

it certainly adds credence to everyone advising using a custom cam grind

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Re: revelation about comp cams shelf cam grinds

Post  BBFTorino on June 16th 2016, 12:22 am

That's why its a shelf cam. One size fits all.

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Re: revelation about comp cams shelf cam grinds

Post  DaveMcLain on June 16th 2016, 9:46 am

That's right. Generally those cams are simply mass produced by an outside supplier so that they are less expensive too. The profiles are so mild that it doesn't make much of a difference if it is used with rockers ranging from a 1.5 to 1.8 and since they are designed to fit on an .842 lifter diameter very easily this also allows them to work well in engines with larger tappet sizes. Most cam companies to similar things especially with their flat tappet designs and it works fine.


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Re: revelation about comp cams shelf cam grinds

Post  dfree383 on June 16th 2016, 12:38 pm

Glad you figured out the 40 year old mystery LOL
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Re: revelation about comp cams shelf cam grinds

Post  Straubtech on June 16th 2016, 3:25 pm

ChrisH wrote:i just noticed this, but I happened to be looking at Cleveland cam grinds to get an idea about a motor for a friend. I happened to look at the Magnum 282S cam for a  Cleveland and realized it was the same cam as the 282S for a 429. I checked the FE version and 302 version and yes its the same grind.

then I thought surely it isn't the same for a chevy small block. it is the same grind. I checked 7 different motors and the magnum 282S cam is the same cam no matter the motor.

302, 351, 428, 427, 429, 460, 350, 354 apparently all require the same cam dynamics. I would have never dreamed that a major cam company would have put so little R&D into cam optimization for respective motors.

I don't know how pervasive this is through their catalog, but it is sure eye opening.

one note:
when I say they are the same I mean the cam card is the same. ramp rates could vary but cam lobe is not noted, just timing numbers and lift.

it certainly adds credence to everyone advising using a custom cam grind

It is job security for me.

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Re: revelation about comp cams shelf cam grinds

Post  gt350hr on June 16th 2016, 3:53 pm

ChrisH wrote:i just noticed this, but I happened to be looking at Cleveland cam grinds to get an idea about a motor for a friend. I happened to look at the Magnum 282S cam for a  Cleveland and realized it was the same cam as the 282S for a 429. I checked the FE version and 302 version and yes its the same grind.

then I thought surely it isn't the same for a chevy small block. it is the same grind. I checked 7 different motors and the magnum 282S cam is the same cam no matter the motor.

302, 351, 428, 427, 429, 460, 350, 354 apparently all require the same cam dynamics. I would have never dreamed that a major cam company would have put so little R&D into cam optimization for respective motors.

I don't know how pervasive this is through their catalog, but it is sure eye opening.

one note:
when I say they are the same I mean the cam card is the same. ramp rates could vary but cam lobe is not noted, just timing numbers and lift.

it certainly adds credence to everyone advising using a custom cam grind


They probably don't even grind it in house. No surprise , been done for over 40 years. Just like cam grinders that copy big name , good working cam lobes. They NEVER copy exactly the same , so it's tough to prove they copied it from the guy that put all the hard work into making the original. A degree here , a few thousandths lift there , and boom a "new " profile .

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Re: revelation about comp cams shelf cam grinds

Post  ChrisH on June 16th 2016, 9:53 pm

dfree383 wrote:Glad you figured out the 40 year old mystery LOL

well I knew they were not the best thing going for an engine. I figured they were dialed back a little and somewhat generic.
however I never would have dreamed they would offer the same grind for a GM 327 to a Ford 460 and everything in between.

it basically tells me they just don't care.
I realize they can't tweak cams for all possible combos out there, but if you are caming a boss 302 the same as a 460 you will have some problems.

all I can say is a have bought one shelf cam in my life to serve a purpose I needed, but I would have to be in a real bind before I bought another

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Re: revelation about comp cams shelf cam grinds

Post  Super Snake Steve on June 16th 2016, 10:15 pm

No wonder when I bought my first 2 custom cams from a vender on here and I went for first test drive it felt like I had a NASCAR motor it responded and drove like I alway envisioned and this is a iron headed 429 SCJ that I have had for 33 years and the other cam was for my brothers Bronco crazy torque monster they at both awesome and at the same time 2 totally different motors I will alway buy custom cams from now on

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Re: revelation about comp cams shelf cam grinds

Post  rmcomprandy on June 17th 2016, 11:11 am

AND, I don't think there is any engine family which can better take advantage of a custom ground camshaft than the big block Ford, 385 family of engines

Maybe ... the 348/409 Chevrolet family or MEL Fords.

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Re: revelation about comp cams shelf cam grinds

Post  IDT-572 on June 20th 2016, 5:38 pm

The problem is, when someone unknowing of what you just found, will install one and pick up some power if you do what they say and add a converter and gear. (and be happy)

What you don't know is what you could have had with a custom ground cam.

Randy is correct in saying the 385 series being the engine that probably most benefits from this, and a 4V 335 series probably in that group as well, especially a open chamber 4V 335.
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Re: revelation about comp cams shelf cam grinds

Post  ChrisH on June 21st 2016, 11:19 pm

that was really the reason I posted this. it was because I had no idea how bad it was and figured there is probably others out there that don't realize this

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Re: revelation about comp cams shelf cam grinds

Post  DaveMcLain on June 22nd 2016, 10:50 am

One thing to remember is that you can always call them and have a custom cam done using those same lobes in any combination you want for your particular application. You're not limited to a single pattern cam ground on a 110 lobe separation. Speaking of which I believe that the main reason those shelf cams are ground that way is because it makes them more forgiving when the builder buys a cam that has too much duration for the application.

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Re: revelation about comp cams shelf cam grinds

Post  manofmerc on June 24th 2016, 1:09 pm

Over on the FE forum they swear by that 282 s .That one is almost a standard for a hotted up FE 390-427 cu.in. Another popular FE cam is the comp. 270 s .Go figure ?Maybe these common camshafts work pretty good for someone afraid of seeking a custom grind .Or unable to find someone they TRUST to have one ground to what their engine really needs.

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Re: revelation about comp cams shelf cam grinds

Post  ChrisH on June 24th 2016, 2:57 pm

i actually run this cam in my 501 in my truck. it does work pretty well. i have a lot of torque and the engine makes more power than the truck can hold.
it is the one time i bought a shelf cam. however, i just thought they were a bit more tailored to the specific engine.

a few of the experts on here stated that these companies design them to work decent across the board and be a little forgiving to application.

but my bet is there are going to be engines that it would not work nearly as well in. it would seem these cams will be hit or miss depending on which engine you place it in.

my goal was to install a smaller cam (for engine size) for the torque increase. my 78 4x4 is 6100 lbs and bottom end mattered to me. so i knew i was leaving top end HP on the table for low end torque. i have little doubt now that there is a better cam for my application, maybe someday i will get around to it. but at the time this was a cheap, quick, and easy answer.

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Re: revelation about comp cams shelf cam grinds

Post  jones on June 25th 2016, 1:23 am

I never knew this and it makes me kinda upset. I just bought a off the shelf camshaft for my 300cu Inline 6. I just wanted something a little better than factory, BUT,, according to what you are saying the factory camshaft could in theory be better. Being that it was designed for that specific engine where the comp cam is generic even though they claim it will give you this and that.

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Re: revelation about comp cams shelf cam grinds

Post  DaveMcLain on June 25th 2016, 7:39 am

jones wrote:I never knew this and it makes me kinda upset. I just bought a off the shelf camshaft for my 300cu Inline 6. I just wanted something a little better than factory, BUT,, according to what you are saying the factory camshaft could in theory be better. Being that it was designed for that specific engine where the comp cam is generic even though they claim it will give you this and that.

A "generic" performance cam will have little difficulty out performing the stock cam that came in the engine. It probably has higher velocity more duration, more lift and a more optimum lobe separation for performance. With that said stock cams also come with lobe designs that can be rather "generic" as well. Depending on the year I would bet that your 300 6 probably came with a cam with about 185 degrees of duration at .050 on about a 114 lobe separation.



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Re: revelation about comp cams shelf cam grinds

Post  jones on June 25th 2016, 2:22 pm

DaveMcLain wrote:
jones wrote:I never knew this and it makes me kinda upset. I just bought a off the shelf camshaft for my 300cu Inline 6. I just wanted something a little better than factory, BUT,, according to what you are saying the factory camshaft could in theory be better. Being that it was designed for that specific engine where the comp cam is generic even though they claim it will give you this and that.

A "generic" performance cam will have little difficulty out performing the stock cam that came in the engine. It probably has higher velocity  more duration, more lift and a more optimum lobe separation for performance.   With that said stock cams also come with lobe designs that can be  rather "generic" as well.  Depending on the year I would bet that your 300 6 probably came with a cam with about 185 degrees of duration at .050 on about a 114 lobe separation.



(Keep in mind I don't know what determines a good camshaft for a particular application.) Over the years I have been given the impression that you really have to have a serious combo for any cam grinder to take you serious and put some thought into the camshaft. If I had know this I would have went with a custom grind even if it wasn't a magical race engine. (I went with a NSR camshaft because I just bought new factory replacement valvesprings.)

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Re: revelation about comp cams shelf cam grinds

Post  DaveMcLain on June 26th 2016, 10:42 am

jones wrote:
DaveMcLain wrote:
jones wrote:I never knew this and it makes me kinda upset. I just bought a off the shelf camshaft for my 300cu Inline 6. I just wanted something a little better than factory, BUT,, according to what you are saying the factory camshaft could in theory be better. Being that it was designed for that specific engine where the comp cam is generic even though they claim it will give you this and that.

A "generic" performance cam will have little difficulty out performing the stock cam that came in the engine. It probably has higher velocity  more duration, more lift and a more optimum lobe separation for performance.   With that said stock cams also come with lobe designs that can be  rather "generic" as well.  Depending on the year I would bet that your 300 6 probably came with a cam with about 185 degrees of duration at .050 on about a 114 lobe separation.



(Keep in mind I don't know what determines a good camshaft for a particular application.) Over the years I have been given the impression that you really have to have a serious combo for any cam grinder to take you serious and put some thought into the camshaft. If I had know this I would have went with a custom grind even if it wasn't a magical race engine. (I went with a NSR camshaft because I just bought new factory replacement valvesprings.)

What is interesting about a "stock replacement" camshaft is how much different it probably is from the camshaft that actually came in the engine. I plot most of the cams that come through our shop mainly because it is interesting and it is fun to do. One example right off the top of my head was a Slant 6 engine that I was building for a '67 Dodge pickup. The stock cam was ok except that it had a worn out fuel pump eccentric. I bought a new stock replacement cam and compared the specs which were quite different.

(stock cam) .389 lift 193 duration at .050 intake and exhaust on a 110 lobe sep

(replacement cam) .407 lift 198 duration intake, .415 204 duration exhaust on a 109 lobe separation.



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It is worse today, than it has ever been

Post  valvemotion on June 28th 2016, 6:12 pm

Today, more than ever, you're more likely to get what you pay for. Pride in one's work is being replaced by greed. The next time you purchase a cam, tell them you'll pay double the cost, if you can get a performance guarantee with their cam. Their answer should explain it all.

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Re: revelation about comp cams shelf cam grinds

Post  IDT-572 on June 29th 2016, 12:34 pm

Welcome Mr. Jones good to have you aboard.
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