has anyone had any experience with comp cams new extreme energy camshafts. I am going to build a 355, 11:1 compression and sportsman II heads, just debating on a 292 magnum or an xtreme energy camshaft

Uhhhh.Will i ever get attacked for this...

First of all.
There is no magic
This means that a cam is a cam is a cam.
Ain´t no "black art" about it.

Within specs i´m willing to bet that there will not be more then 10 horses difference between the "best" and the "worst" cam within a range.
In a motor like yours,pick what YOU feel comforable with-as well as your friendly cam tech guy.
I can not emphasize this enough.

Ya see,it´s all a matter of total package.
In other words a cam that will be the "best" one in your case,might be the "worst" one for someone else,maybe just because he changed one little thing.

Or to put it another way.
I happend to be very interested in formula racing.
When they build those 20000rpms missiles,there´s ALWAYS some of them that will deliver 20-30 horses more then the rest of them.THEY ARE ALL BUILT TO THE SAME SPECS!!
I say that it works the same way-but worse-with "our" motors.
Go figure..

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DVC-98.Racing
470 cubes of fogger injected thunder in a 71 z.
racing@mbox303.swipnet.se (http://racing@mbox303.swipnet.se)

My friend built a 355 this winter, 10.75:1 CR, Edelbrock performer RPM aluminum heads and intake (nice pieces) 1 5/8 headers, 750 DP holley, MSD ign, and the 292 Magnum cam. 1.5 roller rockers. Idles about 1400 rpm, has a 3000 rpm stall converter and could use probably 3500 stall. Guesstimate 425-440 horses. Runs damn strong.
The key is the compression. You have enough to run that big of cam.

It is your decision but I know that those heads flow pretty good intake but not that good in the exhaust area.The xtreme cams have more exhaust lift so that might be better.

Well here goes nothing.There is easily a 20 HP difference between the BEST and the WORST camshaft for a given motor combination.This is because not all motors are the same.A lot of camshaft manufacturers also make lines that offer compromises in power for a better idle and such things.There are a lot of variables like the heads intake to exhaust flow ratio,rod to stroke ratio,compression,the intake choice,and the way an exhaust system flows just to name a few.At least that's what miracle workers like David Vizard(who is an extremely accomplished engine builder)have to say.



[This message has been edited by mutant 68 (edited 12-22-2000).]

Relative performance of a camshaft is based on velocity and acceleration. Velocity = How hard the cam hits the lifter, and Acceleration = How fast the cam lobe lifts the lifter.
Given the same specs on a camshaft for duration and lift, there is a wide area where differences from one cam to another can hide.
Simply put, the higher the velocity and the faster the acceleration, the more power you will make and the harder they are on your valvetrain.
I am speaking of the lobe only here. There are other, very obvious, differences in a cam such as lobe separation angle and intake centerline that will also affect the performance.
The real bottom line is cylinder pressure and how the cam relates to it. For instance, the same cam will not perform the same in a 6" rod small block as it will in a 5.7" rod small block with everything else being equal.
A lot of tech guys working for cam manufacturers assume you are a Rube Goldberg and will treat you as such when you call them. There are others that really try to help and will try to point you in the right direction. If you can find one of them, you're in luck. Most cam companies have the CAPABILITY to give you what you need for your application. The tech guys just don't go to the trouble.

Racing, not attacking but if you believe this and chose your own cam with this in mind expect to be disappointed when you finally run your "street" car down the 1320. I know many NHRA Stock Eliminator guys that have spent countless hours swapping cams and converters so as to be a front runner in their class. These two components my friend are the difference between a slug and a rocket.

Freak, the Xtreme Energy line is a good one and will make more power than the Magnum cams when comparing apples to apples. BTW if nothing else perhaps the single most important variable in cam selection after duration is the Lobe Seperation Angle. In addition to those decisions that must be made when ordering a cam there are several variables that can and do reap HP/Torque gains that will show on the time slip including where the intake centerline is stabbed in at and valve lash.

www.homestead.com/headsupchevelles/page13.html (http://www.homestead.com/headsupchevelles/page13.html)

[This message has been edited by racer1320 (edited 12-23-2000).]

67Freak,
It depends on what you are looking for. I am installing the Xtreme Roller in my Big Block for this reason. I spoke with Comp Cams, and talked to my friend who owns a machine shop that has dyno'd both types, and there is definitely a difference and can be much more than 10-20 hp. Where that difference lies is in overall horsepower (the area under the power curve on a dyno graph). The Magnum camshafts have a higher horsepower rating at peak, but this is because their torque and horsepower curves quickly rise to a peak number and then quickly decrease again from that point. The Xtreme cams have a broad torque curve, they rise quickly in the lower rpms, stay fairly high over a range, and then gradually decrease. Comparison: The Magnum will rise to its peak say at 6000 rpm at 500hp then drop off, but the Xtreme cam may hit 450hp at 2500 rpm, gently rise to its peak of 475hp at 5500, then gradually fall off from that point on. Now looking at the lines on a graph, the Magnum looks like a pointed mountain, while the Xtreme looks like a flat topped mesa. What this equates to is that the area under the graph equates to more overall horsepower for the Xtreme than the Magnum. What good is the 500hp when you are only in that powerband for a few rpm. I'd rather have the 450-475hp over a few THOUSAND rpm. Try plugging the cam into a dyno program and you'll see what I mean. You are going to have more of a stump puller off the line with the Xtreme than with the Magnum, but if you've got enough gears (Say 6-speed), and you can mess around with the gear ratios enough to always keep it at the exact rpm for the horsepower and torque peaks then you can benefit from the few extra horsepower of the Magnum. Believe me though, it takes a lot of work, and is expensive to change all your gearing and test it and change it again and test it and.........I think they call it research and development?

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Bing
1956 Chev 150 2dr sedan 302ci
1965 Chev Malibu 2dr hdtp 496ci
1967 Chev Camaro 327ci
Check 'em out at: http://www.members.home.net/mgbing/cremcars.html

Racer1320,
Ditto that too! I believe the Xtreme cam is working its magic by using more duration, while the Magnums use more gross valve lift. Something to think about too is wear on your valvetrain, the Xtreme will be easier on your springs, cam lobes and valves, because it uses longer duration with LESS lift, which also means less pressure on the parts. Go with the roller Xtreme, and you get even more benefit.

My 2 cents. To get "scientific" here.

There are computer programs that will integrate(i.e., find) the area under a curve from X number of rpm/hp or torque points.

Its this area that is the total of either hp or torque power that really needs to be compared.

Doing so and by setting rpm range limits, it will show you why a certain engine cam combination behaves the way it does.

I don't know if it is true or not but its been said that a particular engine produces the same power at both ends of the rpm scale, BUT NOT AT THE SAME TIME!!! And with this power production being the same, its the cam that places/sets it in the rpm range.

This is why you can take a torque cam and run 3.08's from 800 up to 5000rpm and stay with a Fuelie cam and 4.10's that starts at 3500 but will run up to 8000rpm.

What really happens is that the high rpm causes the low rpm cammed engine to run out of its rpm range at the top end unless you have another gear to grab. AND, HENCE, 5 and 6 speed sticks as illustrated being in the new cars now!!!! IMHO.

Merry X-mas. pdq67

Make sure you talk this through with the CC Techs. The Extreme Energy cams are really very good cams. I was running the XE274 in my 406 until I took the motor apart recently and it's a great street cam. I will probably just swap to the hydraulic roller version when I reassemble it (and.... maybe just one step larger http://www.camaros.net/forum/biggrin.gif).

However, understand that one of the characteristics of the XE line is that they build cylinder pressure at lower rpms. This contributes to the broad toque curve. CC recommends that you use the XE series in motors with 9.5 to 1 or less compression for this reason. Since you are already planning on 11- 1 compression I'll guess that the CC Techs will steer you to a cam - like the Magnum perhaps - that will tend to bleed off cylinder pressure instead. This would typically be a cam with a little more duration and more overlap, or both.


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Scott
'69 400SB, Richmond 5-speed; '99 HD Road King Classic
www.geocities.com/sdenning1 (http://www.geocities.com/sdenning1)

I will try again over here!!!

Oh, Mr. Scott, great, you've tweeked the warp drive engines up to 11 to 1. Don't you think the next phase is to install that new hyper-drive CC EX solid cam?

Eh, Eh, Captain, it will be cheaper then the the roller and produce almost as much speed. We can hold the big roller stick for another day, so then if those da-n 5.0 Klingons keep commin' on, we will have an ace in the hole!!!

Right Scotty, you've made your point!

He, He, Merry X-mas. pdq67

What tha?.......Since I am of a different generation I only have one thing to say.........Make it so number 1.

Right on, mutant68, right on!! LOL, LOL.

Merry X-mas to you and your's.

pdq67

Back at ya big guy.

oop's

[This message has been edited by mutant 68 (edited 12-24-2000).]