[PAUL K]

Originally Posted by mjm421

What would make more power? A 450 cfm head at a given boost number or a 400 cfm head at the same boost? If there is a difference, what would it be ?

Depends

[65nss4spdGTO]

Originally Posted by PAUL K

Would one reason be the E-heads have already exceeded the OPs goals? So it would be already proven. Has a CV head done this?

No one with a Pontiac engine has exceeded the same goals as the OP. The goal of this build is a true street driven (long distance) 1500+ Hp.

Calvin Hill
Hill Performance
708-250-7420

[slowbird]

Originally Posted by mjm421

What would make more power? A 450 cfm head at a given boost number or a 400 cfm head at the same boost? If there is a difference, what would it be ?

You would think the 450cfm head but so far the cv1 has had trouble making the same hp/cfm as the other heads do, at least on a na carb engine.

[PAUL K]

Are you sure about that?

Currently are there any high HP turbo CV1 engines in cars running? If so roughly at what horsepower level?

[65nss4spdGTO]

Originally Posted by PAUL K

Are you sure about that?

Currently are there any high HP turbo CV1 engines in cars running? If so roughly at what horsepower level?

No, Can't say I know everyone running cars like that.

I guess I was just looking for someone that could come up with one good reason (not costs) why the Edelbrock head would be a BETTER choice.

Maybe something like it's "smaller port size and higher air speed" would be better for a turbo engine. Maybe the OP should consider Edlebrock D-PORT heads for the smaller CSA and exhaust.

Paul do you think the D-Ports would be a better choice?

Calvin Hill
Hill Performance
708-250-73420

[PAUL K]

Originally Posted by 65nss4spdGTO

No, Can't say I know everyone running cars like that.

I guess I was just looking for someone that could come up with one good reason (not costs) why the Edelbrock head would be a BETTER choice.

Maybe something like it's "smaller port size and higher air speed" would be better for a turbo engine. Maybe the OP should consider Edlebrock D-PORT heads for the smaller CSA and exhaust.

Paul do you think the D-Ports would be a better choice?

Calvin Hill
Hill Performance
708-250-73420

Calvin I think the E-round ports would be a better choice over d-ports.

I personally don't think his goals would be hard to achieve using either a CV1 or an Edelbrock head. I feel it would make the most sense to use his existing heads since he already has them(but I have no further info other than what he has posted). I would also feel a person would be better off using a head that has been proven unless they feel like being a pioneer.

I don't follow the CV heads...... are there any high horse turbo heads currently in service?

[twinturrbo406]

Originally Posted by PAUL K

Calvin I think the E-round ports would be a better choice over d-ports.

I personally don't think his goals would be hard to achieve using either a CV1 or an Edelbrock head. I feel it would make the most sense to use his existing heads since he already has them(but I have no further info other than what he has posted). I would also feel a person would be better off using a head that has been proven unless they feel like being a pioneer.

I don't follow the CV heads...... are there any high horse turbo heads currently in service?

... JDWPONCHO is turbo CV-1 ...

[mjm421]

Originally Posted by PAUL K

Depends

I'm looking for an explanation here. Everything depends on something??

[slowbird]

Originally Posted by twinturrbo406

... JDWPONCHO is turbo CV-1 ...

What has he ran?

[twinturrbo406]

Originally Posted by slowbird

You would think the 450cfm head but so far the cv1 has had trouble making the same hp/cfm as the other heads do, at least on a na carb engine.

... Kelvin Poe's Hill Performance/CV-1's made 2.24 hp per cfm vs 2.11 hp per cfm for his Dan Barton ported HP's ...

[Jeff Kinsler]

How fast have the cv1 turbo cars been?

I know there are quite a few out there..

[BruceWilkie]

Originally Posted by PAUL K

Would one reason be the E-heads have already exceeded the OPs goals? So it would be already proven. Has a CV head done this?

What power goal? Pump gas requires lower inlet temp than race gas methanol or e85... Plenty of ways to keep inlet temps in check... intercooling, water/meth injection or simply lowering boost psi.

Boost is a measure of restriction to flow... Higher flow capacity heads can allow lower boost PSI(which directly affects manifold temp) and still flow the same mass of flow for same power. Alternately more mass flow at higher boost to same inlet temp point the more restricted heads would have...greater power.

Calvin listed most the reasons and options on the cv1's... here is a few not mentioned... very sturdy rocker stands allowing studs vs shafts to beyond lift points other heads start needing shafts for strength(also uses common easier to find BBC rockers should you need to replace a rocker with short time to find/borrow )...

Another feature is cooling... the cv1 inner casting has features that help pull more heat from critical areas than other heads...
All cv users have noted improved cooling and no one has reported collapsing of the exhaust center bolt boss with traditional or convertible exhaust.

Adding convertible exhaust feature not only allows easier turbo manifolding(proven NA advantage as well)... it allows even less heat around the centerbolt as it puts ex ports above the outer bolts...heat rises and with center ports above ex center bolt it gets exposed to less heat. An improvement compared to other non symmetrical ex port heads that are not easily converted to non droopsnoot. CV2 RAV Warp6 style has centerbolt exhaust heat advantage for the extreme range... IMO not needed for pump gas turbo or street/strip combos and methanol powered cars have a hard time getting/keeping heat in them and thus centerbolt gets less heat thru it.

http://forums.maxperformanceinc.com/...=618756&page=2 post 25 Rob is currently building something wilder with his cv heads...

http://forums.maxperformanceinc.com/...ighlight=turbo

Early CV1 Results.... 4.5 psi boost shakedown runs (close to 4200 lb stage weight) Bankbooks first CV1 combo...
(he has upgraded his original cv package)

There are other turbo builds... running or in progress... Jim Sammons probably knows status better than I... contact him.

[slowbird]

Originally Posted by twinturrbo406

... Kelvin Poe's Hill Performance/CV-1's made 2.24 hp per cfm vs 2.11 hp per cfm for his Dan Barton ported HP's ...

Has any cv1 been over 2.4hp/cfm? All other alum Pontiac heads have.

[Tom Vaught]

Originally Posted by mjm421

What would make more power? A 450 cfm head at a given boost number or a 400 cfm head at the same boost? If there is a difference, what would it be ?

Mike, How about instead of racing "Boost levels" we say MASS FLOW thru the head.

If you have 1 pound of Air Mass you can basically make 10 horsepower.
So if you want to make 1500 horsepower you need 150 pounds of air mass going thru the engines cylinder heads every minute.

In one case to get that 150 pounds of air mass thru the engine at 8000 rpm the 450 cfm head's intake manifold might show 22 pounds of boost pressure.

In the second case to get that 150 pounds of air mass thru the engine at 8000 rpm the 400 cfm head's intake manifold might show 25 pounds of boost pressure.

The boost gage is just showing the pressure drop across the cylinder head's ports, valves, and intake manifold. BRAGGING RIGHTS for the smaller head but same HP at the flywheel.

A couple of PSI difference in the readings is not worth the expense to buy the 450 cfm head. The Butler's have a 482 cubic inch engine with lets say a 350 cfm head. 50 cfm less vs the smaller head in your example.

Both of the 400+ cfm heads make 1500 HP.

The Butler's at 45 PSI make 2800 HP. They have less cfm heads but are moving 280 pounds of air mass thru their engine at the same 8000 rpm with a higher boost gage reading because their Turbos are designed to work at 45 psi.

The other heads might have turbos that are only happy running at 25 PSI.

AIR MASS, AIR MASS, AIR MASS

Tom V.

[Rusty4cyl]

Bill, You make me laugh. You talk about Kelvin's motor, because it made more horsepower with cv-i's than it did with HP's. Let see, Kelvin's motor with the CV-1's now has more cubic inches, the cam is different, intake centerline is different, and Barton's HP's flowed 388 compared to Hill's CV-1's that flowed 435. I would bet a million dollars that the new motor would make more horsepower, if not somebody really screwed up. A 435 head to a 388 head, maybe you can compare that CV-1 to a Ram Air 4 head too. Give me a break already. I'm done Thanks Rusty

[PAUL K]

Originally Posted by twinturrbo406

... JDWPONCHO is turbo CV-1 ...

How fast has he been?

[mjm421]

Originally Posted by Tom Vaught

Mike, How about instead of racing "Boost levels" we say MASS FLOW thru the head.

If you have 1 pound of Air Mass you can basically make 10 horsepower.
So if you want to make 1500 horsepower you need 150 pounds of air mass going thru the engines cylinder heads every minute.

In one case to get that 150 pounds of air mass thru the engine at 8000 rpm the 450 cfm head's intake manifold might show 22 pounds of boost pressure.

In the second case to get that 150 pounds of air mass thru the engine at 8000 rpm the 400 cfm head's intake manifold might show 25 pounds of boost pressure.

The boost gage is just showing the pressure drop across the cylinder head's ports, valves, and intake manifold. BRAGGING RIGHTS for the smaller head but same HP at the flywheel.

A couple of PSI difference in the readings is not worth the expense to buy the 450 cfm head. The Butler's have a 482 cubic inch engine with lets say a 350 cfm head. 50 cfm less vs the smaller head in your example.

Both of the 400+ cfm heads make 1500 HP.

The Butler's at 45 PSI make 2800 HP. They have less cfm heads but are moving 280 pounds of air mass thru their engine at the same 8000 rpm with a higher boost gage reading because their Turbos are designed to work at 45 psi.

The other heads might have turbos that are only happy running at 25 PSI.

AIR MASS, AIR MASS, AIR MASS

Tom V.

Thank you Tom. What power would the 450 cfm head make at the same 45 psi. or the 350 heads at 28? Thanks, Mike

[john marcella]

Originally Posted by mjm421

I'm looking for an explanation here. Everything depends on something??

Truth is it does depend.

Air flow in terms of CFM at 28" is not the big deal, more the min area cross section. Also the boost level is important because this will determine air speed in the runner or rather how much time the air speed will be at its LIMITATION. If the power adder remains the same but the heads have different CS and flow differently ,then the boost with the same power adder will not be the same. Pretty much at 30 psi the air speed in the runner is at its air speed limitation in the runner THE WHOLE TIME. The way it makes more power above 30 psi is because the air is denser but it still travels at no higher speed than the air speed at 30 psi. So approaching 30 psi the larger CS head would far out do the smaller one, regardless of how much air it flowed on a bench.

The whole idea behind this is air can not travel faster than the local speed of sound in a pipe/runner.

[Daniel Barton]

Originally Posted by twinturrbo406

... Kelvin Poe's Hill Performance/CV-1's made 2.24 hp per cfm vs 2.11 hp per cfm for his Dan Barton ported HP's ...

I think its very interesting that you find that to be an even comparison. Let me ask you and all the guys in the CV-1 camp so to speak, from designer to modifier such as you and Calvin to current and past users to just fans... I've heard and actually read on several occasions it said that there is some sort of active campaign to "ruin" Jims business. Have you or anyone heard this, or said it and actually believe it to be true?

[J.C.you]

going to be a long winter....