Another head question, maxed out vortec?

[10secTy]

Just to make this simple.

Vortecs will make enough power to break a stock block stock crank motor.

Unported Vortecs have gone 10.71@126 at 26psi on Tonys truck.
If you do the math that is 600hp at the rear wheels.
With lower shift points and locking the converter in 2nd he has gone
10.9@128.5 at 21psi.

when we dynoed the truck we had gains up to about 25psi then after that we had gains but not as much they tapered off.

The bottom line is that I feel his turbo was maxed out and not the heads.

If he had better heads it he would have maxed the trubo at say 24-25 psi instead of 28psi.


The Vortecs have alot going for them price wise, driviblilty, reduced Deto.

If you have a bowtie block and billet crank look at aftermarket heads then.

Oh and for the Record the Vortec V8 heads and V6 heads are not the same.
The port sizes are different.

Nolan

 

[100in6]

damn nolan! you're one smart guy!!! do you like go to bed at night with earphone on thats playing all this info into subliminal messages or something?????

I'm impressed. I'm definitely buying you and the little woman dinner at the nationals this year. maybe some of this smart stuff will rub off

les

 

[PCS74]

While we are on this subject with some good info, I have a question/theory, etc.

Does PEAK flow really matter with the turbo stuff?

Being as the flow #'s are tested under vacuum.

What are the changes involved in flow when under pressure -vs- vacuum.??

Another thing is doesn't the total flow, aka area under curve, have a big affect. Just like HP, if you peak at 400hp, but only make 100 everywhere else, that can't be as good as 300hp everywhere.

What are some people thoughts on this???

Short and to the point:


Peak flow, all by itself, shouldn't be taken as the sole indicator of a heads power potential. You are right, the "area under the curve" is the priority. It is affected by many different properties of the head.

Turbo/supercharged engines operate on the same principals as NA engines. The piston motion creates a low pressure area in the cylinder and atmospheric pressure forces air into the cylinder in an attempt to reach an equilibrium condition(Yes even NA engines are forced induction). In a turbo/supercharged environment the same events are happening, only you are increasing the pressure differential across the valve; therefore, increasing the total mass of air delivered to the cylinder.

Chris S

 

[HotRodV6]

Well i think for the money the vortecs cant be beat by anything in the aftermarket, that even taking into account the cost to modifiy the stock intake to bolt up. The Brodix heads are a great head, but cost 1500 a set bare, then you figure another 500 or so for the machine work and valve train parts, thats 2 grand, and on the -8 heads brodix says (in a phone conversation i had last month) they flow 235-240 out of the box, well a stock vortec will flow around 230, and fully ported the most i have heard of a vortec making was 290, but that was using a small amount of epoxy, with no epoxy they will flow 280-285 no problem, and the fully ported -8's, will flow around 290 without epoxy, but wont make as much power unless you raise the CR, which brings up another point, because with stock CR, the vortecs will hold more heat and make more power than the Aluminum -8's, So for a mild engine, I.E. stock block and crank i would stick with the vortecs, but if you want to all out , bowtie block billet crank, bilet caps, 12:1 pistons, than your only choice should be the brodix heads, and another difference is the -8's are a 190cc intake runner, the -10's are a 210cc runner, and the -11's are 220cc runners those are all out of the box numbers. All can be made with either straight or angle plug, and are a use a perimeter bolt valve cover. Also the combustion chambers are around 68cc on all heads.

Hope this answers anybodys questions.

Mike