I'm sure by now most have heard about the LS7 for the New Z06s...500hp 427ci engine. I was reading about the engine specs in recent magazines....

What makes me drool is the heads on them...12 degree valve angles, eliminated pushrod pinch, 2.200" intake and 1.610" exhaust valves, FULL CNC porting...

360cfm on the intake flow
210cfm on the exhaust flow

At engine's peak valve lift"
I assume that's at the cam spec's 0.593"/0.588"

Short of selling my house and buying one....how can I build a well budgeted thirdgen using Gen I head and compete?? 18 degree heads are too expensive...but I don't think they even flow that well. Best AFR has are these:

http://www.airflowresearch.com/pages/215sbc_rr.htm

I'm ready to build my 5-Speed car into a "terror". Plans are in the works...400+cubic inch small block with the BEST heads I can manage. I think the ones above are going to be it...
But...I'd still be a step behind a new Z06 with a Camshaft change!!!

Is it time to give up the Gen I ghost and go LS?

 

I wonder this same question often. It's hard not to look at the LSx motors which get great power, great gas mileage, light weight, warranty, and respond well to mods and not go "Damn!". While I know a regular big inch SB can do some of them can it do it for the cost and reliability. No one can say the general doesn't have it together when it comes to V8s.

 

When the C7 comes out, you'll be in great shape to buy a C6 Z06. Unfortunately, by then a C7 with a cam change will probably hurt the C6 like an Asian prostitute.

 

You will not need anywhere near that kind of head flow for a 500HP 400+ci SBC. Something around 290/210 to 300/220 would work well. I believe AFRs Competition 220s would do wonders here with a nice solid roller and a single plane.

BTW - Even a 500HP engine won't get you C6 Z06 performance... They weight A LOT less than you. You'll need to shave several hundred pounds or look for a good bit more power. GM claims conservative 127mph trap speeds!

 

Forget 500 hp a good engine builder can get with a 383ci sbc...

Estimated Horsepower Based on CFM -
HP = .2575 x CFM (@ 28" of water) x number of cylinders

Using the above formula and ~0.600" lift flows for comparison:
The LS7 heads should be good for about 740 hp.
The Raised runner AFR 215 heads should be good for about 655 hp.

Is there a better head available than the AFR 215 that will sway me from considering going LSX? I'd rather be a step ahead than a step behind. Granted, I can't afford the LS7 anytime soon, and the AFR heads and Gen I small blocks match up well against the LS1,2, & 6...but times, they are a changin.

 

This is nothing that a 572ci Big block won't cure.

 

http://www.araoengineering.com/Chevy/chevysmb.htm
say no more!
pricey though
Eric B

 

There are alot of aftermarket heads that outflow the LSx.Power cost money.There is a member here that makes something like 800 hp NA with a 400 CI sbc (look up member Seejgo).makes u want to say LSx what???


big blocks are the way to go if u are not stuck with using sbc.

 

I like the new stuff and the old. I have an LS1 but haven't done much with it cause it is so expensive. Even gaskets and tq. to yeild bolts are out of hand. Can't beat the old stuff for bang for the buck.