99SS-T

iTrader: (5)

Im tryin to cut down on the build so that i can get it on the road now and then over winter get the parts that take a month to get. Like AFR heads. So im wondering what kinda power or PSI yall think i should limit myself to with GM cast heads. Ill be at about 9.0-1 CR with 72cc heads. I know its all in teh tune i got that part down pat but at what point would it become a issue.
Also i tried search 3 times and it appears to be borked. I woudl much rather have just searched out the answer as im sure this is asked and i just missed it.
If u have any input and maybe my parameters of teh answer dont work for ya then answer it the way u can make it make sense. Thanks Guys

John

JAvenger007

iTrader: (9)

661rwhp on the stock bottom? Is there a forged setup in your garage ready to go?

Theres 750+hp setups running 317 cast heads. Some have gone to 900hp without lifting. What are your goals? Are you keeping the phamspeed kit? That way you can determine if a GM head will get you there, so you can save the $.

LTLHOMER

iTrader: (10)

Have gone 157 mph at 3450 lbs (gotta be close to 1000 at the crank I think?) on stock 241 castings (ported)...20-22 lbs of boost. No problems thus far have around 30 passes on it.

y2khawk

iTrader: (5)

170mph on 317 heads here.

99SS-T

iTrader: (5)

uhhh ok well that settles that lol. Every Engine builder i talked to said no way in hell over single digit psi lol. Obviously that is conservative but 170 mph sells me lol. Ill get other heads in teh winter.
Also i do have the forged engine now but i made 630ish for about 6 months with not a single problem. I attribute alot of that to my partner in crime Jerm, aka Zombie. He got me a great base tune for the car and i did some minor tweaking to make that power at 11.0 afr at 12 psi. I was happy but not enough.
Im definatly still gettin darts or afr's not decided on that yet. Anyone have any ideas on how big the bowl cold be ported on dart or afr heads to get a bigger CC size? Or is there a point where its takin away from teh mechanics of the combustion chamber mechanics? Thanks for the help guys!

John

LTLHOMER

iTrader: (10)

So you asked if GM heads would cut it...you get replies that say yes they will cut it way past the power you want...and then you say:
I don't get it? What was the point of making the thread if you had your mind made up already? lol

JAvenger007

iTrader: (9)

I'm also confused? What kind of power are you hoping for?
The above says a lot about those LQ9 heads. Is zombie running 317s also?

Zombie

iTrader: (2)

Thanks for the kind words I love seeing the stock bottom end get pushed. I'm just bummed that I never got my 700 rwhp stock bottom end dynosheet when I was 6spd to brag about Funny part is the tune/advice was done over AIM of all things LOL

P.S. got two other local guys making around 600 rwhp on stock motors and they have been doing it for 8 months now.

Zombie

iTrader: (2)

You betchya. My heads have stock valves, good springs (some comp springs, not sure which ones, 130 seat pressure) and a 3 angle valve job. I'm nowhere near the level of the guys above though, but my goal was a fun fast street car. I'd eventually like to see a 140mph trap though but I realize that is a VERY lofty goal, right now i'm just after a 130mph trap LOL The Las Vegas heat is holding me back. Maybe I'll go T88 next year, need to see how the car runs in winter here.

My setup is an uber budget build, i'm quite happy with it too.

WAHUSKER

iTrader: (4)

I'm hoping to hit 650rwhp & 800rwtq this weekend with my 317 heads. I'm at 9.3 CR & running ~ 14 psi. I think if you use good gaskets & bolts (studs) you'll be fine. I think your stock bottom end will go away long before the LQ9 heads develop a problem.