Supercharged Smallblock Combination.

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Scampin

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Well guys I will start this off by saying Hi!
I have been lurking throughout this forum for awhile and have been brewing the next motor combination for my 71 Plymouth Scamp.

The current motor is a 10:1 360 with the mopar performance .450 hyd. cam, stock "x" heads, edelbrock air gap intake, generic 1 5/8 headers, 2600stalled 727, 8 3/4 w/ 3.23 gears. It ran low 13's (avg. 13.20-.24 @ 105mph w/ avg. 1.87-.84 60's).

I kinda put it on the back burner for a turbo'd import. (don't bann me.) Which was fun and expensive. But after putting the 4th. motor in, in only 14k miles I decided to give up on that project. However I will never go back to N/a ever again. Which leads me to this... (Sorry for the long intro.)

I want to supercharge the Scamp. I have sent emails back and forth to Bob @ the supercharger store. We came up with a neat decently priced package including fuel system, methanol injection system, and needed supercharger stuff. The package is set-up for the future motor I want to build...

Plan for new motor (Serious amount of constructive criticism needed/wanted)

Mopar Performance R3 340 Race Block,
Forged 4" Stroker crank,
Eagle H-Beam rods,
Some sort of custom pistons for approx. 8:1 compression,
Edelbrock Al. heads, (340 ones or the other ones?)
Airgap Intake,
Ati D-1 procharger, (approx. 10-20psi depending on detonation resistance)
1 3/4 fenderwell headers (Do I need bigger?)
750 Demon blow-through carb.,
MSD ignition, (Do I need boost-retard, or should I lock out the dist.?)
Cam (?)


Do I need the R-3 block? The thick webs and 4-bolt mains are added ease of mind, but my goals are not to be breaking any speed records.
The R-3 block can be bored out to 4.22" I believe, but I'm wondering if the Eddy Heads are capable of supporting that much cu in.? Should I run a roller cam? Is it really worth the added cost?
Anybody know of a site in which you can find the specs. of pistons companies make to maybe match up a set that would work with my needs? (wishful thinking I know, but I am flexible with bore size if I get the R3 block)


Finally my goals are to go fast enough to need a roll cage without question. I would like to run 10's without breathing hard. Also I want to be streetable enough to not think twice about driving 400miles to the nearest big mopar show. I was told that I didn't need 448cu in and 18psi to do this (the estimated guess for hp was an easy 700-800 on pump gas lots more with better gas).

Do you guys think I should get the r-3 block or am I over thinking things as usual?

((Re-cap for people with A.D.D. - what do I need in a smallblock to run 10's with a supercharger and be dependable and streetable enough to not worry about it))

Thanks,
Brian
 
Welcome Brian,
You were talking t the right people at the supercharge store.
On guy you could also talk to is Tweety (Andy) he's been playing around with the prochargers also.
Norm
 
Welcome. Can't help you much on the engine combo, but your plans make my 416 stroker sound kinda puny.
 
Thats a whole lotta tire.
I don't really even want to mini-tub the Scamp, but I know it's gonna be necessary. I wonder if he kept the Nascar style compression ratio?
 
GotDart said:
Welcome. Can't help you much on the engine combo, but your plans make my 416 stroker sound kinda puny.
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Funny you should say that. My father thinks this is a plan to upstage his car. ( AAR cuda, 402cu in. 10.2:1stroker, Looks completly stock, runs 12.50's on polyglass tires through exhaust manifolds and weighs 3900lbs)

He's right though :evil4:
 
Its not going to tale much to get a 4" stroker small block with a super charger in to the 10s. The hard parts going to be getting it to hook.

Welcome aboard.
 
I am keeping the 3.23gears in hope of helping the traction issue out.
 
Well after talking with Bob @ thesuperchargerstore I ended up ordering an F-1 (Read BIG) supercharger kit with his methonal/water injection kit. Apparently the D-1 was gonna be too small for me. So the plan now is to set it up at an easy 10psi and make around 750hp on pump gas, then tune from there and up the boost.
I ended up getting the Mopar 340 replacement block (4 bolt mains, very thick walls) so it won't be too crazy in the cu in. dept. Maybe 402-410cuin. Also going with highly ported cast iron heads instead of al. (Got a deal I couldn't pass up)

I'll post some pics of the supercharger stuff gets here.
 
why do you want to use the Air Gap- with a supercharger wouldn't a single plain be better? and if you really want to go nuts- get some indy heads they'd reaaly like to breathe through a supercharger!
 
mrspeeddemon said:
why do you want to use the Air Gap- with a supercharger wouldn't a single plain be better? and if you really want to go nuts- get some indy heads they'd reaaly like to breathe through a supercharger!
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Last time I checked the air-gap was always within 5-10hp peak of single planes, plus they have that nice fat torque curve. On top of that I already have it, so it will be one less thing to buy.
I have a friend that bought the indy worked edelbrock heads. He had them flow tested in which they made 272cfm @ .700(may have been .600). The cast iron heads I now have were flow tested at the same bench and made 254cfm @ .550.
For me I don't think they are worth the money at this point. Maybe when my goal is to make 1000whp on pump gas. hehe. :iconbigg:
 
dont use the edelbrock 340 heads...they are designed for use with a postive deck piston..not what you want to be running. i would recommend going with the INDY-360 heads as they come complete with valvetrain and matched intake and flow better, price is about the same when you factor in what it would cost to port the eddy's+intake+valvetrain.
 
340duster340 said:
dont use the edelbrock 340 heads...they are designed for use with a postive deck piston..not what you want to be running. i would recommend going with the INDY-360 heads as they come complete with valvetrain and matched intake and flow better, price is about the same when you factor in what it would cost to port the eddy's+intake+valvetrain.
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DITTO, I agree
 
I'm thinking you wont see 700 hp with that combo. Not enough in there for what the blower will draw to make it. I would also scrap the iron heads..10psi isnt enought o pass that kind of air thru those small ports. Also, an air gap is worthless..The blower will be making power, you'll just be generating a lot of heat in taht dual plane. I klnow you already ordered it, but I would have gone turbo. Much less parasitic draw from the engine, and easier on things like the crank. That's a huge load on the snout. Bowers were cool, but turbos are the way to run and make the big #s now.
 
340duster340 said:
dont use the edelbrock 340 heads...they are designed for use with a postive deck piston..not what you want to be running. i would recommend going with the INDY-360 heads as they come complete with valvetrain and matched intake and flow better, price is about the same when you factor in what it would cost to port the eddy's+intake+valvetrain.
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Thanks guys. Good points.

I have already bought these heads. They flow pretty damn good, so we will see how it goes.
 
moper said:
I'm thinking you wont see 700 hp with that combo. Not enough in there for what the blower will draw to make it. I would also scrap the iron heads..10psi isnt enought o pass that kind of air thru those small ports. Also, an air gap is worthless..The blower will be making power, you'll just be generating a lot of heat in taht dual plane. I klnow you already ordered it, but I would have gone turbo. Much less parasitic draw from the engine, and easier on things like the crank. That's a huge load on the snout. Bowers were cool, but turbos are the way to run and make the big #s now.
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I am trying to follow you but I'm not sure if I am getting exactly what you are saying. 10psi on that blower should be plenty for a starting point to tune from. 750hp seems high, I agree. However that is the estimated ballpark for the combination.
Worked cast iron heads seem to be doing pretty good when paired with a supercharger.. http://www.thesuperchargerstore.com/martyfox.html

After reading a few comparo's again on the Airgap intake (granted, none on F/i cars) they were within 5hp of the single planes. In my mind I would rather take the extra mid-range than the 5-10hp at peak.
This is not going to be a drag only car. In fact the suspension set-up is going to be geared for road course/better handling.
I whole heartedly agree with you on the turbo thing. Turbo's are "free" hp. However, to even think about getting one in my car the fenderwells would have to go, then all the tubing, plumbing, wastegates, etc. Then to make the big numbers and be somewhat street usable I would have to go with twins. On top of all that one of my close friends is doing a turbocharged dart sport....I can't copy him. lol
 
Iron heads cant make as much, no matter how nuch force you use to push the air thru. The problem is cross section..Most iron heads (Baring W2s) dont have enough to move the air volume required. You boost is backpressure in the intake system..That's what it's hitting for resistance. Like water in a hose, or oil flow..Press is a resitance to flow..Not the flow itself. Smaller port will reach 10psi faster, especially when paired with a larger blower, even a centrifical model. And that 10 psi will make less power overall, then 10psi of boost with something say 20% larger in cross section. Also, you want to be sure that the engine produces 750hp at the crank, when under boost. If it were me, I'd run an intercooler, and ditch the carb idea too. Not having looked to see your flow numbers, I'd say you will fall short with any factory iron head I'm aware of, even in ported shape. Also, for the intake, your midrange is produced by the blower..As is your top end..The only thing to keep in mind would be low rpm operation, because it wont be moving a ton of air right off idle. But, that's also what the convertor is supposed to help with. Blowers and turbos are different animals..Not my strongest area either..You may want to hunt around for some info on designs before you continue buying stuff. just my $.02..
 
Scampin said:
After reading a few comparo's again on the Airgap intake (granted, none on F/i cars) they were within 5hp of the single planes. In my mind I would rather take the extra mid-range than the 5-10hp at peak.
This is not going to be a drag only car. In fact the suspension set-up is going to be geared for road course/better handling.
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What your reading about is naturally asperated comparo's- when you strap on boost the whole theory changes- the air gap will work, but not necessary. A single plane will be much more efficient
 
moper said:
Iron heads cant make as much, no matter how nuch force you use to push the air thru. The problem is cross section..Most iron heads (Baring W2s) dont have enough to move the air volume required. You boost is backpressure in the intake system..That's what it's hitting for resistance. Like water in a hose, or oil flow..Press is a resitance to flow..Not the flow itself. Smaller port will reach 10psi faster, especially when paired with a larger blower, even a centrifical model. And that 10 psi will make less power overall, then 10psi of boost with something say 20% larger in cross section. Also, you want to be sure that the engine produces 750hp at the crank, when under boost. If it were me, I'd run an intercooler, and ditch the carb idea too. Not having looked to see your flow numbers, I'd say you will fall short with any factory iron head I'm aware of, even in ported shape. Also, for the intake, your midrange is produced by the blower..As is your top end..The only thing to keep in mind would be low rpm operation, because it wont be moving a ton of air right off idle. But, that's also what the convertor is supposed to help with. Blowers and turbos are different animals..Not my strongest area either..You may want to hunt around for some info on designs before you continue buying stuff. just my $.02..
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The cast iron heads I have outflowed a set of edelbrock aluminum heads on the same bench. They were within 18cfm peak flow of a set of edelbrock aluminum heads that were worked over by Indy. They flow very well for a set of cast iron heads.

I am going to be running a Water/methanol injection set-up. Which is much more efficent than a conventional air to air intercooler. Also much less plumbing to do.

I have done a ton of research on this. That is how I came to my decision to purchase the supercharger, it is much more practical for what I want to achieve. I have talked to several people running cent. superchargers, asked them set-up ideas, pros & cons, etc. Not many people have tried a dual plane and no one I know of has run the Air-gap. I'm curious to see how it does. If it doesn't produce good numbers than I will throw on the M-1 single plane I already have, no big deal.
I'm alittle unsure of why you don't think the cast iron heads would produce 750hp. I gave you a link for a cast iron headed smallblock making 1000hp at 15psi. According to the tech. people my heads are flowing right about the same as his.

P.s- Just watched a D-3 supercharged (carbureted) smallblock chevy at 8psi and pump gas run a 10.80 @ 136mph....
 
10.80s can be run on a carburetor with a small block chevy. And a 350 to boot. But I digress. I went to the link. Very little info, nice looking truck tho. What are these heads exactly, and what did they flow? Notice the large plenum under the carb? I'm also very curious what they used for dyno exhaust. I'm saying it's totally impossible, just not the best way to go about it. You still have to kep the alcohol/water filled. I wouldnt bother with it. The water to air aftercoolers are pretty trick if the intercooler isnt your speed. I'm sorry, just an opinion. Obviously, do what you want. I've not been a fan of the centrifical chargers, because i dont like giving up all that power, and the build is similar for both. I'd use aluminum heads, to help keep away from detonation, thru material and design, and because they can be made to flow much better easily. I've been involved in several blower engine jobs, mostly on Fords and GM..but I dont own one. I've been able to get what I needed without the added expense and complications boost of any sort adds.
 
moper said:
10.80s can be run on a carburetor with a small block chevy. And a 350 to boot. But I digress. I went to the link. Very little info, nice looking truck tho. What are these heads exactly, and what did they flow? Notice the large plenum under the carb? I'm also very curious what they used for dyno exhaust. I'm saying it's totally impossible, just not the best way to go about it. You still have to kep the alcohol/water filled. I wouldnt bother with it. The water to air aftercoolers are pretty trick if the intercooler isnt your speed. I'm sorry, just an opinion. Obviously, do what you want. I've not been a fan of the centrifical chargers, because i dont like giving up all that power, and the build is similar for both. I'd use aluminum heads, to help keep away from detonation, thru material and design, and because they can be made to flow much better easily. I've been involved in several blower engine jobs, mostly on Fords and GM..but I dont own one. I've been able to get what I needed without the added expense and complications boost of any sort adds.
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Anything can be done with any motor. All it takes is money. Those were magnum heads, I do not really get into flow number racing unless it is the same bench and operator. The exhaust was 1 5/8 headers and imagine open exhaust but I don't know for sure.
Other people running the water/methanol injection set-up reported around 1.5 to 2 gallons per 1500miles, of course this is very dependent on driving style. It runs off a 5gallon fuel cell and is activated by a boost pressure switch. I think I can handle paying 3dollars for 3 gallons of blue washer fluid every oil change interval. Air to water intercoolers are not practical for street driving, which this car will see more than anything. Plus why would I add all that weight to the front end when I can run something easier to set-up, cheaper, and more effective?
I agree with the detonation resistance of the aluminum heads, they disappate heat much more quickly and effectivly. I may end up going to a set of indy's down the road. But all I need the supercharger to do at this point is add around 200hp to the motor I have. It ran 11.90's in a 3900lb car, my car weighs 3200 with me in it. I'm going to have a set of pistons made and throw a set of cometic gaskets in.
As for you being able to make any motor do what you want to without power adder's. Good for you! I just don't know how to make an engine have F/I, sound like it's blown, have a shiny supercharger under the hood without actually doing it!?!lol
 
Scampin,


Sounds like an interresting combo, I hope that when you get it together, you will let us know how its working out. I have been thinking about one for my 440 and there are very few guys around my area that run one.

Good luck
Jim
 
I'm just wondering why you never considered a centrifugal supercharger and use a blow-thru carb set-up. They are making some pretty decent ones nowadays and you dont have to have that (IMO, crap) sticking thru the hood basicly screaming RACE car. I know some think it's cool, but phhht, I like a car with balls that also looks like it belongs to my great grandmother, even if it would cause her to have a stroke (I speak facetiously, my great grandmother is dead, God rest her soul.) Sounds like you gonna have some fun one way or another. Good Luck to ya.
 
krabysniper said:
I'm just wondering why you never considered a centrifugal supercharger and use a blow-thru carb set-up. They are making some pretty decent ones nowadays and you dont have to have that (IMO, crap) sticking thru the hood basicly screaming RACE car. I know some think it's cool, but phhht, I like a car with balls that also looks like it belongs to my great grandmother, even if it would cause her to have a stroke (I speak facetiously, my great grandmother is dead, God rest her soul.) Sounds like you gonna have some fun one way or another. Good Luck to ya.
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Not really sure what you are talking about. The F-1 Procharger is a centrifugal supercharger that sits under the hood. And I am running a blow-through carb.

I totally agree with you on the looks thing also.
 
Scampin said:
Not really sure what you are talking about. The F-1 Procharger is a centrifugal supercharger that sits under the hood. And I am running a blow-through carb.

I totally agree with you on the looks thing also.
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My bad. I saw the response by moper and got me thinkin you were doing a roots style set-up.
 
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