Originally Posted by MILD THUNDER (Post 3587517)

If your going to the aluminum head, I'd get the compression up. The stock 7.5 or so to one is pretty dismal. 8.5:1 with the aluminum heads is good.

Sounds like your on the right track, but no way 700HP with the stock blower and 7.5:1.

I can tell you this. I ran 460CI, dart race series alum heads, mild port work, 308cc intake runners, hyd roller 236/245 114LSA, compression was about 8.3:1. With the 177 blower, I was turning the blower at 2:15:1 overdriven. Making about 4.5-5psi. I then went to a 250 blower, drove it at 1.68:1 overdriven, gave me 5psi. 1.8:1 gave me 7psi.

On my engines, if i wanted 7psi, I probably would have had to drive the small 177 to 2.3:1. Turning the engines to 5500RPM, thats almost 13000 rpm blower speed. Talk about a heat pump. The bearings probably wouldnt last long, and the added boost would really do nothing for power.

The more cam, better flowing heads, will drop the boost psi. Once you start getting into that stuff, you outgrow the small blower quickly.

To get near 700HP, I'd say 250/256 blower, up the compression, 7-8psi with a chiller. Im currently rebuilding mine, H-beam rods, JE pistons, and adding 8-71s. If i get 700-725HP at 5500-5700rpm I'll be happy.

Originally Posted by MILD THUNDER (Post 3587548)

288/298 .629/.632

intake opens 8.0* btdc
intake closes 48* abdc
exhaust opens 61 bbdc
closes 5* atdc

114lsa

its a custom hyd roller cam for a supercharged 454

Originally Posted by supermx96 (Post 3587480)

I am in rebuilt now of mine, I have swap the rod for Callies Compstar H Beam, .030 oversize with block valve notch, Speed Pro forged piston, new aluminum Hedelbrock Performer RPM head 45 cfm more than the stock head, Crane costom grind 114lsa with less overlap 67 deg than the stock one 74 deg to keep the boost in the cylinder, estimate comp ratio at 7.5:1 - 7.6:1.

I will possibly get a porting job on the head for an extra 30 cfm or so.

I estimate at least 650HP possibly 700hp if i am lucky.

I think i will be able to keep the boost at 5.5 with the stock pulley due to less overlap on the cam and smaller intake runner 315cc instead the 325 or 335 stock.

The stock cam is very not good for this surpercharger setup.

I keep the comp ratio low for a bigger blower in future and boost arond 7 with a 250 or 671 blower.

Originally Posted by Griff (Post 3587558)

Like was already said, more than 600hp with the stock 177 blower, stock boost and comp ratio is not gonna happen.

Originally Posted by MILD THUNDER (Post 3587573)

7lbs of boost with a aluminum head is not a problem at 8.5:1, using the right blower. Add a chiller and get even more. Aluminum heads are superior in that they dissapate the heat so much better than cast iron.

You are actually better off running a bit higher static compression with a small blower. You wont have to drive it so hard to make decent boost.

If your running the 7" drive pulley, with a 2.85" upper, thats 2.45:1 blower ratio. If your propped for 5500RPM, , thats 13,500 blower rpm. I believe weiand stated no more than 13000 rpm with those blowers, and thats mainly on the street. 13500rpm for sustained wot runs in a boat, i'd be nervous about it.

Originally Posted by JD33 (Post 3589395)

What is the dia. of the stock pulley for these blowers?

I'm pretty sure mine have not been changed but just want to be sure.