ok, i'm quite new to forced induction and i figured i best get learning some about it right now before i consider purchasing anything... i kinda need to know some basic stuff about F.I. like how much boost can i run with my application? and what kind of CR you want to run with a supercharger, cuz i'm pretty sure that 11:1 is a bit much with a supercharger so i figured i'd buy a new set of heads with a bigger combustion chamber when the time came. but i want to know if i'm able to just buy a supercharger and bolt it right on without having to re-inforce the shortblock if i keep teh boost low enough, like say 8 psi? but i'm looking at a weiand pro street supercharger in my summit magazine, part number WND-6512-1. so if someone wants to look that up and tell me what they think about them, that'd be nice. other than that, i'm just looking for advice in general! i'd like to keep away from rebuilding my entire motor for this so i'll list what i have and hopefully someone can tell me what i can and can't do with my application.

1972 350 4 bolt main.(0.030" over)
zero-decked and clearanced for 400 crank.
Eagle rotating assembly with cast steel 3.75" crank.
Eagle SIR Lightweight I-beam rods.
KB hypereutectic -7cc flat top pistons(10.9:1 with 64cc).
clevite 77 rod and main bearings.
premium plasma moly cast iron rings.
camshaft is 234/244 and .488/.510 hydraulic
weiand intake topped with edeljunk 750 electric choke.
hooker super comp long tubes and 3 inch dual chambered mufflers.
now for the heads, i have a set of dart pro1 215cc, 2.05/1.6, heads picked out. but i'm unsure of the supercharger thing yet so i haven't decided on 64cc(10.9:1) or 72cc(i think 9.7:1). that decision will be made later.

thanks in advance!

 

That 177 is only going to be good for around 500-580HP at the crank, after that its not going to beable to keep up with the engine.

Going witha roots style, its going to make some more heat, i wouldnt recomend running any FI on anything 10.5:1 or higher with Iron heads, at that CR ur going to get issues, even with very low boost, meaning even at 6 PSI with 92 ur going to Ping, the timing is going to need to be so retarted the benefit from getting that 177 is not going to be worth it.

IC in your profile you have ur engine rated, if those are close to being correct then yea the 177 wont do much at all, even with 76-78cc heads. If you want more than 550 at the crank, then move up to an all forged set up. That eagle set up is going to be pretty close to its limits around 500. If you really want to get into it, rebuild it forged, drop the compression to the 8's.

If you want a supercharger like that one go for the 6-71 or 8-71. they run around 2,600.

 

ok, well my rated hp was with the new heads i plan on getting, they actually woulda been here bout a week ago if i could only make up my mind on what i want, lol. well all i expect to get out of this 177 is about 100-125hp so that'd actually be ok with me. about the CR, thats why i haven't purchased the heads yet, becuase i don't know what kind of compression you are able run with a supercharger so i haven't yet decided. whatever heads i decide on will be aluminum though, i already know that. thats the only reason i'd be able to run the 11:1 CR anyways. if you think the 177 won't benefit me much, what about an overdrive pully on it and increasing the boost a little bit? this is kinda the area i'm unsure about, i don't really know how much boost a steel crank and the SIR lightweight rods can take. but if i did put this application on my car, is it true that i won't need anything else being redone? maybe a bigger carb or have it altered for a s.c. but other than that i can pretty much just pull off my intake and bolt this thing on there or what? but thanks for everything so far, i'm bound and determined to learn about this forced induction yet!

 

The carb you have now will work on top of the 177, but even with overdrive pullies, it can only flow so much air, for a 350 it bascily runs out just above 500. Most engine components can handle boost OK, the problem is detonation, if it detonates on weaker parts, then they are toast, if its forged it might live. If you can get the compression down to 9.7 with the new AL heads, then you could use the 177 for a gain, its just that ur pushing it so hard with overdrive pullies, that its going to be making more heat, causing detonation. When you do drop the CR, dont look into using head gaskets to do it, spacing between the top of the pistion and the head needs to be .025-.045, tighter is better, but might caust pistion slap depending on clearances in components.

I would look at a different way to add boost if your going over 450 crank HP. Im looking into getting the ATI Procharger carb set up. $2,200 for P1SC, brackets, piping to carb hat, and carb at, pullies and belt. Its a great price and it will support 550crank HP easy. Add an intercooler and ur still under $3k andhave a great base for power. If you run a blow through set up, you have to modify the carb to handle it properly. More information on boosting a carb set up can be found at Here

 

hmmm... well with the CR thing, i haven't bought the heads yet, so i can buy the 72cc chambers and that'll drop me to 9.7:1. so i can keep my .035" quench. well i'd like to spend around $2k at the most for now. if i get that procharger then can i get the supercharger and set up now and then get an intercooler later and add it on for more boost/efficiency? if i needed i can probley get even lower compression, but what i'm asking is what is the ideal compression to run for a blower set up? since i don't have heads for it yet, i can pretty much go to whatever CR i need, or atleast close to it. so would like 9.0:1 be better yet? or is 9.7:1 good? i guess now i'm open for suggestions on the most increase with the shortblock that i already have, and i'd like to keep the bill around $2k if possible.... speaking of that, how much boost do you think i can run on my shortblock that i have now? i guess thats enough questions for now, thanks so far!

 

you need around a 8.5cr for blower use..
If you want some psi & power at less..

& also forged piston !!!

 

thats for what kind of psi? i dont' need a forged piston for only like 8 psi do i?!? i don't plan on running like 12-14 psi through this thing, i just want enough to know its there... maybe add a hundred horse or so. can't i run like 8psi at like 9.7:1 and with the pistons i have? i'm not lookin for something to hold up to a 6-71 or 8-71 blower. just a little bit of power is all.

 

You sure can add an intercooler latter. IF you dont add one imidiately, you need to atleast go with some new Aluminum heads, and get the CR as low as possible, are the pistions flattops? Ideally, you want Flat top pistions, that .035 or tighter quech area, and an 8.5:1 comp ratio. If you stay with what you have now, i would not recomend running any boost, drop the CR some, then you can safely add 6PSI to a non intercooled 9.7:1, 8PSI is pushing it with out intercooler, get an intercooler, possibly alky injection, AL heads, and the lowest CR you can with out changing pistions and you can safely run 10 or so PSI. Really you need to build the eninge for boost.

AL heads will get you close enough to start running the smallest pully size on a Procharger. More money spent now the better off you are latter, and the cheaper it will be in the end.

 

ahhh ok then... ok so lets talk theoretically for a second. lets say i got these dart pro1 aluminum heads that i'm looking at getting: 72cc chambers, 2.05/1.6 (maybe 2.08/1.6? which would be better for supercharger?) and 215cc or 230cc runners(again which is better). the compression would be about 9.7:1 and they're aluminum. i have -7cc dished flat top kb hypereutectic pistons. now, what kind of psi can i run with and without an intercooler on a procharger? and what kind of hp increases can i expect at both? thanks for everything so far!
Dustin

 

anybody got any advice or info for me? please?