Comp 268-10

-
bobscuda67

bobscuda67

Well-Known Member
Joined
Aug 27, 2005
Messages
2,106
Reaction score
387
Location
Michigan
I was killing time on Sunday and I read an old thread where RRR recommended a Comp Magnum Muscle cam for a small block. I was just wondering if anyone uses one on their car and how does idle and run? There are certainly cams with faster ramps and will make more power for the same money.
It has about 12* at .050 more than a factory 340 cam and .020 more lift and I would think it will be easier on the valve train than an fast rate cam.
They sure can't be selling very many.
 
For street use, with a FTHydraulic, Personally, I would run the fastest ramps I could find.
But the cam I would select would be the right one for the intended useage and it would put the power where I would want it to be. And I would not care what it idled like. And I would also not much care about the lift. I would let the cam grinder take care of that. And I would run the springs he tells me to, at the installed height he specifies. And if he gives me a rev-limit, then that is what I would set mine to.
But this is for street performance.
If you just want to sound nasty, well that's your right.
Me, I just want to pull up to the nastiest sounding guy in town, with my sneaky little 367, that has almost no lope to it's 230* cam, and when he nailsit, I'm just gonna dog him for a bit. If he bothers me again, maybe I'll downshift, and dog him a lil closer.If he does it again, one of two things is gonna happen; A) if I'm smart, I'll turn off, but, if my bank account has some spending room, then B) He can dog me for a bit.
The point is this; a nasty sounding cam does not automatically make your car fast.
And this; a well set-up combo, that's COMBO, can really fly!
But if sounding nasty is your thing, there's no arguing that, cuz that's what I wanted ,once. And I installed the almost legendary 292/508/108. This cam sounded capital n NASTY! But it made its nastiness from about 5500 to 7000rpm. And I had street gears, the much sought-after 3.55s.And 5500 was 47mph. I cannot tell you how many times I waited and waited, and waited for the power to arrive. And then when it finally did , BOOM!, it was all over cuz right there in the middle of my dash it was screaming STOP! you're speeding!
Yeah so I got tired of waiting for the power to come around.
I re-evaluated where I wanted the power to be. And I bought me a teensey-weensey cam. One that made torque right off idle. One that was ready to go before I was. One that when I said NOW!, it was already GONE! Yeah those were fun times.
OOps, did I get sidetracked again? sorry.
So what are the specs on that Muscle Cam?
 
bobscuda67 said:
I was killing time on Sunday and I read an old thread where RRR recommended a Comp Magnum Muscle cam for a small block. I was just wondering if anyone uses one on their car and how does idle and run? There are certainly cams with faster ramps and will make more power for the same money.
It has about 12* at .050 more than a factory 340 cam and .020 more lift and I would think it will be easier on the valve train than an fast rate cam.
Click to expand...

Consider the cam a friendly half step above the factory 4bbl. cam.
They are easy on the valve train which helps keep things quite & long lasting. I have not run one though I do remember this as a popular cam for ingeneral use with a lot of people back in the day. How there selling now is a mystery to anyone except the bean counters. I figure, if it is still offered, it is selling.

It is a proven cam often found in hot - ish 318 4bbl. set ups and mild 340/360 builds. Something easy to do with out a big hassle thata more serious cam would bennifit from like new slugs, ported heads, steeper gears and/or stall converters. It works reall well with a small 4bbl. carb. Headers are a plus.

Everybody states or says or just simply runs to a faster ramp rate cam. The power differences are there and they are slight. As with anything, if you keep adding on little power makers, and add them up, it can become a significant amount at the days end. I'll save the "FAST RATE RAMP CAMS" for a serious build up and the race rides. Also, if you (Or anybody here) think that the XE line is a fast ramp rate, LMAO!
Well, OK then, LMAO, have a good day and be happy with that!
 
Best to discuss your build and what you want with a custom cam grinder or err" on the small side of duration for the street.
...Hard to beat a cam ground for your combination by a cam specialist.Expect to pay a little less than double over an off the shelf cam.
 
It's a 268/274 with a lift of .464. The duration at.050 is .222/226 on a 110 lsa/ 106 centerline. The intake valve closes at 60*.
I would think that the idle would be near stock in a 340 but be noticeable in a teen.
From what I've read a 340 cam was [email protected] so this would be a couple steps up in duration.
 
For me,(EDIT a streeter), I'd pass on that one. Those ramps are just too slow. And if you're not careful that ICA of 60* will kill the low-speed performance.So you gain 10 or 12 hp at 5200, but when the idle to 2000 takes a dump, then what do you do?

5200 with 3.55s and a 4speed is about 44mph; but you still have to get there!
If you have an automatic, things are looking up; 5200 is about 46mph, but a 2400 TC gets you thru the soft zone.

As to fast-rate cams being hard on valve trains;I can't speak to that, except that 46* from advertised to 050 is in no wise fast. And if your parts are well thought out and properly installed,their lifespan should not be an issue.

Furthermore some cams are advertised at .006 tappet lift, some at .008, and others who knows. So comparing rates of lifts by using the advertised-to-050 gets to be tricky. As long as you are shopping in a single catalog, you can do ok. But be careful when switching catalogs.Also, not all suppliers are forthcoming about where their advertised are measured from. Also, the ramp speeds after .050 can vary all over the place especially when they are climbing to different lifts.(EDIT; this is the whole reason that the 050 spec was adopted in the first place, to make it easier for us to compare the possible performance of different cams; an apples to apples comparison).
One thing I thing I think I have learned is that when choosing a cam of a certain duration, the one with the highest lift is likely to have the fastest flanks.I say likely to have.If you can prove that, then perhaps you can move DOWN one cam size, lose no performance as compared to a cam from a different supplier, and reap the benefit of a higher Dcr, with an attending stronger bottom end torque delivery.
To see how this works;
Suppose you are interested in a 268 cam,(edit; not any particular 268 cam, nor the cam the OP is talking about), that is also a 222 @050, but the 268 is measured a .008 tappet lift. This cam might actually be a 272 at .006. So the manufacturer tells you his cam makes, more power than every body elses 268, and sure enough it does, so you are hooked on this manufacturers cam and tell all your friends. The truth is it's not just a 268. Its also a 272. So it makes a bit more. Now this cam has ramps of 268-222=46 degrees advertised. But in truth it is; 272-222 = 50* But he ,the manufacturer, is able to say 46 cuz it is that too. So if you unwittingly buy into that nonsense, and tell all your friends, and some of them buy into it, pretty soon you have a nice business going.Every body is buying big slow-ramp cams that they believe are powerful fast-rate-of-lift cams.
EDIT; to reiterate, I am not talking about any specific cam. The point I am trying to make is that buyer beware and compare apples to apples.
Be vewey,vewey kaaweful.haahaahaahaa!
That's my best Elmer Fudd. It sounds better if you read it out loud.
 
Last edited:
Got one in my 73 340 Duster that has a 360 in it....Idles great...great low torque too...
Engine is a 360 .020...plus stock J heads with 1.88/1.60 valves ...Eddy Performer RPM with currently a holley 750 DP....
 
What's your compression ratio?
Have you ever had a chance to get some track time on it?
 
AJ, you would pass on that cam it n favor of what? You haven't used that cam so you ACTUALLY don't know. Have you taken a ride in a car with that cam?

Write all the math you want and blame that cam as crappy all you want due to what you think are to slow of a ramp.
Until you use one or take a ride in a car with one......
 
bobscuda67 said:
What's your compression ratio?
Have you ever had a chance to get some track time on it?
Click to expand...

Compression is 9.4 to 1.....
If it make it to the track it wont be until late this fall...got to many other projects miles ahead of it...
 
rumblefish360 said:
AJ, you would pass on that cam it n favor of what? Something with faster ramps and more lift? You haven't used that cam so you ACTUALLY don't know. Have you taken a ride in a car with that cam? no

Write all the math you want and blame that cam as crappy all you want due to what you think are to slow of a ramp.
Until you use one or take a ride in a car with one......
Click to expand...

I think there is a miss-communication here.
The cam in my story has nothing whatever to do with the cam in the OPs question. It is the story of a cam I once purchased, with very similar specs. The cam I installed and am talking about is 270/276/110@106 and lift of.504/.515, which I installed with 1.6 arms for about 6.7% more lift. This cam is 223/230 @050 the advertised to 050 is 47 degrees. It was advertised as a fast rate-of-lift, and words like--our cams make more power and carry it further, than our competitors---type lingo. Well I bought into that, and can't compare it to the competitors,for obvious reasons, but I preached that cam to all MY friends. This 270*cam a GREAT cam! the advertising as to it's carrying the power is probably right. I know it revved to 7000 and more,with the recommended springs.
I was in no way implying that it was a crappy cam
But that was in 2002. I am more knowledgeable today. At least I think I am. I now know why that cam pulled so hard. It was actually bigger than 270. it was rated at .008 tappet lift, whereas most other manufacturers rate theirs at .006 tappetlift. And that was the point of the story. I'm sorry if that was not clear.
Now as to that 268 cam, it runs best in a hi-compression engine. Don't be sticking it into your 8/1 teener cuz it will be extremely soggy on the bottom. If your lucky it will make 6.6Dcr@125psi.
This 268 cam needs at the minimum 9.5 Scr, and 10.0 is better.
And finally this cam needs gears to put the power where it needs to be. If you want an explosion of power on the downshift into first at 32mph you will need 3.73s in an A-body at least, and 3.91s would be better. This is getting out of the realm of streeterhood, cuz cruising the hiway will be a little on the buzzzzzzy side.
And I guess that is where the miscommunication might be; I forgot to say streeter somewhere in my post. So I'll just go fix that right now.
 
rumblefish360 said:
Consider the cam a friendly half step above the factory 4bbl. cam.
They are easy on the valve train which helps keep things quite & long lasting. I have not run one though I do remember this as a popular cam for ingeneral use with a lot of people back in the day. How there selling now is a mystery to anyone except the bean counters. I figure, if it is still offered, it is selling.

It is a proven cam often found in hot - ish 318 4bbl. set ups and mild 340/360 builds. Something easy to do with out a big hassle thata more serious cam would bennifit from like new slugs, ported heads, steeper gears and/or stall converters. It works reall well with a small 4bbl. carb. Headers are a plus.

Everybody states or says or just simply runs to a faster ramp rate cam. The power differences are there and they are slight. As with anything, if you keep adding on little power makers, and add them up, it can become a significant amount at the days end. I'll save the "FAST RATE RAMP CAMS" for a serious build up and the race rides. Also, if you (Or anybody here) think that the XE line is a fast ramp rate, LMAO!
Well, OK then, LMAO, have a good day and be happy with that!
Click to expand...
This is a proper explanation, without personal interjection. Perfectly described, Rumble....
 
bobscuda67 said:
It's a 268/274 with a lift of .464. The duration at.050 is .222/226 on a 110 lsa/ 106 centerline. The intake valve closes at 60*.
I would think that the idle would be near stock in a 340 but be noticeable in a teen.
From what I've read a 340 cam was [email protected] so this would be a couple steps up in duration.
Click to expand...
On paper, that's a nice grind.... 60 degrees of overlap(yes , I use that as a concept of street abilities, and eventual effects on fuel mileage...) is street able.(Depending on gears , and transmission & converter choice).
 
I ran that one years ago in a 340. Excellent camshaft. Passed emissions sniffer I had to do at the time. Idles nicely but with a lope, great torque, pulled clean past 7K on several occasions. This was in an otherwise stock '68 340.
 
Would using 1.6 rockers help the bottom end a little? It would get the valves to almost .500 lift and speed up the ramp st the valve.
Sounds like it is ideal for a street driven car.
 
are you using headers or manifolds?
higher overlap (i get 59) will waste power and gas with manifolds and soften
lo speed torque...just what you don't want on the street.
..and like AJ says ..faster ramps produce power and are efficient.
 
ir3333 said:
are you using headers or manifolds?
higher overlap (i get 59) will waste power and gas with manifolds and soften
lo speed torque...just what you don't want on the street.
..and like AJ says ..faster ramps produce power and are efficient.
Click to expand...

Yes with manifolds.
I'll bet you could get an a body into the 13's with an otherwise stock 340 with a street tire with this cam. It would be easier on the valvetrain and quiet.
 
bobscuda67 said:
Yes with manifolds.
I'll bet you could get an a body into the 13's with an otherwise stock 340 with a street tire with this cam. It would be easier on the valvetrain and quiet.
Click to expand...

with manifolds i would look at a cam with specs like Voodoo 702.
 
ir3333 said:
Best to discuss your build and what you want with a custom cam grinder or err" on the small side of duration for the street.
...Hard to beat a cam ground for your combination by a cam specialist.Expect to pay a little less than double over an off the shelf cam.
Click to expand...




BOOM!

The Great White North nailed this one.
 
I'll add... I had it in an Ebody with 3.23s. There is no soft bottom end. Least none I experienced. After I broke the 340 it went with the x heads and bolt ons onto a 70s 318... none there either. It's a great cam, and there's no reason to adjust what you have.
BTW- the car would run 13.5 off the spray, 12.70s on it with the 340. Drove it daily for 3 years like that.
 
Oh yea there's no question that the faster rate cams are more efficient but the there is a cost in the durability of the valve springs.
It says a lot that people that have used the cam had great success with it.
 
bobscuda67 said:
Oh yea there's no question that the faster rate cams are more efficient but the there is a cost in the durability of the valve springs.
It says a lot that people that have used the cam had great success with it.
Click to expand...

that Comp. muscle car cam may very well be a cam you will like.My friend is using it in his 408
and it does idle with a bit of attitude.
 
You must log in or register to reply here.
-

Back
Top