[Badbird69]

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

[T Syron]

Nice comparison. Here come the haters.

Tom Syron

[S/st 54]

That's pretty cool! Congrats on both! I know you spent Some time doing all that it's kinda rewarding seeing and answering your own questions.

I hope you have the same such luck that I had with the track numbers!Either way I wish ya the best!

[mike leech]

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!

[mike leech]

dang it! i'm third!

[GTO Dan]

Great test methodology and nice back to back. Interesting to see how they perform on the track in back to back.

Those CV 1 certainly showed the strength on that stock bore, wonder if any difference using an aftermarket large bore.

Congrats to the CV 1 folks and to you for the impressive results.

[David Holmberg]

Great test and results.

Now get to the track and lower that record.

[john marcella]

Originally Posted by Badbird69

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

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!

[GTOLou]

Great stuff -

What number of pulls per each head did you do? The averages for each was based of two pulls or three pulls?

Thanks!

[steve25]

Thats just what I would expext from the CV1s with there more consitant port area over the wide ports and the CVs higher short turn, some 3/8 th inch over the wide port set up.

[WARPed]

This is great news and shows the CV-1's are doing what they were designed for in the first place - a less expensive topend/valvetrain to deliver at least as good e wide port power. One bonus using CV-1's would be you are at the starting point as far as porting goes while the wide ports are near there max & another they run cooler.
Good Job!!

[LiL Jack]

Originally Posted by WARPed

This is great news and shows the CV-1's are doing what they were designed for in the first place - a less expensive topend/valvetrain to deliver at least as good e wide port power. One bonus using CV-1's would be you are at the starting point as far as porting goes while the wide ports are near there max & another they run cooler.
Good Job!!

No CV1 motor can come close to a max E head.

That's the bottom line, sorry to burst your bubble.

[johnta1]

Maybe you can loan him your Eheads to compare to the CV-1?

[BruceWilkie]

Originally Posted by LiL Jack

No CV1 motor has beat a max E head optimized car yet at equal weight equal engine size/cam/carb. Any excuse we can find!

That's the bottom line, sorry to burst your bubble.

Fixed it for you!


And when it does??? EVERY excuse Jack can find!!!

[Jeff Kinsler]

congrats everyone is happy.. CV1TTFMF......................... now lets race.....

EHTTFMF

[LiL Jack]

Originally Posted by BruceWilkie

Fixed it for you!


And when it does??? EVERY excuse Jack can find!!!

There are no excuses on the ET slip.

Just saying

We don't calculator race, dyno race or Internet race we race down a racetrack.

Pound per pound you can not beat us.

[john marcella]

Originally Posted by BruceWilkie

Fixed it for you!


And when it does??? EVERY excuse Jack can find!!!

"YET" I believe would be correct. At some point the CV has to out do the best E-head combo. It has to. CV head has greater potential than a rpm e-head for sure. The Problem is that the bar is no longer set with the rpm e-head. Its Tiger, High Port , Pro Port, Warp 6. JMO, Just sayin.

[65nss4spdGTO]

Originally Posted by LiL Jack

No CV1 motor can come close to a max E head.

That's the bottom line, sorry to burst your bubble.

Jack still believes the earth is flat too...


Calvin Hill
Hill Performance
708-250-7420

[LiL Jack]

Originally Posted by 65nss4spdGTO

Jack still believes the earth is flat too...


Calvin Hill
Hill Performance
708-250-7420

Lets see..

Kinsler E Headed NA....8.42 @ 3300#s

Me 7.94 @3460#s

Please tell me another cv1 car that has come close to either of these times at anywhere close to this weight.

And please don't make excuses about the East Coast air, it gets old.

[twinturrbo406]

Originally Posted by 65nss4spdGTO

Jack still believes the earth is flat too...


Calvin Hill
Hill Performance
708-250-7420

... LMAO ...