daddy33

iTrader: (5)

well i building a 383 engine and going the buy the new AFR Eliminator 215cc heads. I want to put the Weiand 177 blower on top and match it with a blower cam. Im aiming for around 600HP and wanted to know what should my CR be if im going to be running 6-8lbs of boost? Most likely ill run 6lbs daily driving and bump it to 10lbs if i go to the track or a dyno. any input would help. thanks

-tino

Sonix

iTrader: (1)

around 8:1 would probably work.
With a 383 you'll need big soup dish pistons, and 76cc heads.

daddy33

iTrader: (5)

see i know AFR has 76cc heads but as far as piston wise i cant find many companies that had dish top pistons for a 383. the closest i found made 8.75:1 CR with the 76cc heads.

Sonix

iTrader: (1)

I know 22cc cups exist, and i'm pretty sure 30cc does as well.
I think Keith black makes both of those sizes actually.
Not sure who else though.

leeperryracing

have you contacted ross pistons? my blown 383 had their -22cc forged slugs in it.

TurboedTPI

If your only running 6-8 lbs i would run 9:1-9.5:1.

Sonix

iTrader: (1)

with a roots blower, going into carbs, probably with no knock sensor?

TurboedTPI

Oh, maybe not with a roots blower, unless its intercooled.

89gta383

iTrader: (5)

SRP and JE make 383 pistons with a -28cc and -31cc dish.

JEPistons.com | SMALL BLOCK CHEVY - EXTREME DUTY 23º INV. DOME

leeperryracing

8:1 is what you want to run some boost thats worth a sh*t.

Tony89GTA

iTrader: (7)

trbo355

You will be spinning that blower for all it's worth if 600 hp is your goal. Even with a 383 the blower is too little for much over 525-550 hp. On a 383 if you run the littlest top pulley which is a 2.5 inch, you will only see about 8-9 lbs out of it. My buddy has a 350 with vortec heads and a decent roller cam and the smaller 144 blower and makes 9 psi with a 2.5 pulley good for about 500 HP even. You will make GOBS of torque but over 7-8 lbs on the little blowers makes for a LOT of hot air. Everything my bud Joe and I screw together gets wrung out for all it's worth and we have learned this. Big 6-71 blowers good to 14-15 lbs. Little blowers good to 9 lbs on gasoline. Alcohol is a whole different story. We tried up to 20 psi on a megablower 420 and made the same HP at 13-14 psi. Now if you spun that baby for all it's worth and meth injected it, you might be able to hit 600 but it would leave the tune on the ragged edge with a hot timing number and meth dependent to keep it's nose clean. Not a very good street combo for the HP number. I say do the 177 anyway since the torque output of those paired with a torque producing 383 stroke would be fun as hell on the street!

83 Crossfire TA

iTrader: (2)

It’s kind of a loaded question….

WRT to what has already been said, running the fuel through it will have some intercooling effect. What compression you get away with will depend on the parts used in the engine, head design and especially camshaft timing. That being said, if all those were in appropriate ranges I’d probably be shooting for something in the high 8’s to about 9:1. the 8.75:1 is about perfect.

If you’re really shooting for 600 hp I doubt that you’ll do it with that blower.

daddy33

iTrader: (5)

Well im shooting for 600HP and still trying to maintain street manners. Would a centrifugal blower be more capable of doing so? If the roots type wont make it then maybe i should switch the setup. Maybe ProCharger or vortech? Anyways i just want around 6-8lbs boost on the street with a 383. I already have the new AFR Eliminators w/ 75cc.

TurboedTPI

Yes, i think a centrifical blower would be alot more streetable, And more efficient too. And if you go with an intercooled setup, you'd be able to run more boost than a roots on pump gas.