[Stan Weiss]

Originally Posted by Slick

From Dick Fulton's Post:

A few months ago, amid the ongoing controversy of CV-1 versus Edelbrock wideports, we agreed with Roland Racing to do some independent testing. As I stated before, Jim Sammons did not ask for a blind endorsement - he asked for an honest evaluation. Most objective people realize that somewhere between all of the hype and all the bashing, lies the truth.

We decided to do back-to-back dyno tests using our stock block 475 motor. We did our best to make this a fair comparison using the same short block, headers, carb, rocker arm ratios and equal compression ratios.

The Edelbrock heads have obviously been ported into the wideport configuration and are fitted with titanium valves. The intake is a ported Victor. The CV-1 heads had some bowl blending, but otherwise untouched "as cast" ports. They were supplied with standard issue stainless valves. The intake was ported and gasket matched locally. Both valve trains consisted of Manley springs, T&D 1.7 ratio shaft rockers, 3/8" pushrods and Crower rollers.

The shortblock is a filled 455 block, billet main caps, lifter bore braces, 4.22 bore, 4.25 stroke, forged crank, aluminum rods, gas ported pistons, light ring package, custom roller cam (lobe .445, .440, duration 276, 284) standard firing order, good oil pan, crank trigger, dry decked, 11:1 compression. Accessory pieces include an external water pump, stepped headers, vacuum pump and a Shaker prepped 1150 carb. Nothing too exotic here.

No jetting changes were made to either combo. Because the CV-1 heads were new to us, we moved the timing around to see what it liked. That's it. We simply warmed the motor up, adjusted the valves and made some pulls.

Our dyno pulls were from 5500 rpm to 7700 rpm, with a test range of 5500-7500 for average torque and horsepower comparisons. Those who have been to the dyno know that there are raw numbers and corrected numbers. Corrected numbers are calculated to correct the raw numbers to what they would be at sea level. Many race teams only look at the raw numbers, as the correction factor is not always dependable. Raw numbers are rarely as high as corrected numbers and are therefore not nearly as exciting, but they are real. For the sake of comparison, we will show the average raw numbers. For the sake of interest, we will show the corrected peak horsepower numbers.

Again, the test range was from 5500 rpm to 7500 rpm.

Raw average torque and horsepower for the wideport E heads were 539.8 and 659.8 respectively. Peak corrected horsepower was 781.0 @ 7100 rpm.

Raw average torque and horsepower for the CV-1 heads were 562.8 and 694.3 respectively. Peak corrected horsepower was 815.7 @ 7000 rpm. It was still making 805.8 horsepower @ 7500 rpm

I think all of our jaws dropped when we saw the raw numbers come up. Seeing a set of unported street heads outperform our ported race heads was impressive, to say the least.

Clearly, this test will not put to rest all of the doubts, but it certainly shows great potential. Just think what they will do with a little port work. If time allows, we will test this motor in the car this fall.

Dick Fulton

In the same thread, from Mike Leech:

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mike leech mike leech is offline
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very nice write up! good job on keeping it as fair as possible as well. And kudos are in order for the cv1 "gang". As i have stated before the heads obviously have potential....and this looks to be a fair comparison. Question...Same cam and headers?

I said i would be the first to say good job, and i am. Good job!
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In the same thread from John Marcella:

Did you do this for the E-head combo as well?(Timing)

Also what was the chamber volume of each set of heads? What was the fuel curve like fore each set of heads?
What was the cross section of the victor at the plenum? Stock? (don't want to be testing the manifold, just heads right?)
Why was the CV compared to a old E-head and not a High Port or PP or Tiger?

I know im on the list of Haters, but im not really.
I think the CV has its place, and have actually recommended it to people a few times with in the last year.


If the Victor Cross section at the plenum was adequate, and fuel curves were "ON" for both, and timing was "ON" for both, and camber volume was the same for both.............................................. ....Then I say CONGRATULATIONS to the CV camp , GOOD JOB!
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John Marcella
Marcella Manifolds Inc.
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ph. 248-259-6696

Do not worry. Someone will be a long shortly. As soon as they drink some Kool Aid and put on their secret decoder ring to tell you what all of that actually means.

Stan