My 408 supercharged stroker build

[golden73]

Ok everyone, I pulled out my 360 a few weeks ago and have it disassembled.

Here is what I have planned, feel free to make comments/suggestions:
Forged 4" crank

Forged H beam rods 6.123"

Forged pistons 9.0:1 compression

Eddy alum heads, stage 3 ported 2.08" intake 1.60" exhaust

Harland sharp roller rockers- don't know which ratio to get

Either eddy air gap, or mopar m1 single plane?

Centrifugal supercharger with intercooler from sd-concepts

I am also going to get hi-flow oil pump, fuel pump etc.

The parts I don't know what I should get would be valve springs, pushrods, lifters. Any input would be appriciated.

Also, are there any mods that should be done to the block before I take it to the machinist?

[Blown70]

I do not know enought about the supercharger you mentioned but it depends on your overdrive.  9:1 is high very high for a supercharged engine.  Again maybe its the type you are using.  Most have a final compression of 14:1 depending on the amount of overdrive you run.?  Go too much you will see head gaskets shoot out under extreeme pressure..... NOT PRETTY.... well kinda fun to watch.

[golden73]

I was talkin to an engine builder and he said you could go as high as 9.3:1 with an aluminum head. I thought it was pretty high too.
Maybe 8.5:1 is more reasonable?

Here is a link to the supercharger site: http://www.sd-concepts.com/index.htm

by the way, what would you guys suggest for a stall converter? i was thinkin somewhere in the 3000-3200 range.

any idea for a cam?

[Jon Smith]

centrifugal supechargers are a bit more forgiving on compression than roots blowers, but you still probably want to be around 8.5:1 on pump gas

[Blown70]

Thank Jon.  I was pretty sure a ROOTS would not do that.  I personally would do 8.5:1  too.  I think mine will be 7.5:1 of couse with the 10-71 shoving air in it will be significantly higher.

As far as cam what is your primary purpose.  STIP alone.  I would speak to your engine builder but strokers can be tough to deal with if you dont know what you are doing.  At least that is my opinion.

Same for the stall speed/rpm.  Depends on use IMO.

[golden73]

This car will be taken to the strip, and will see the streets as well. It will not see more than 1000-1500 miles a year. It will need to run on 93 octane though.

[Silver R/T]

we need Neil's advice on this

[golden73]

  Ron would be a big help too

[morepower]

Well with aluminum heads a 9:1compression ratio should be fine because due to heat dissapation of aluminum the ratio wil drop nea a point.
THe valvesprings u buy will have to match the camshaft.
YOu would have to get custom length pushrods as you should on any engine build.

[Silver R/T]

whats the website address where they sell those centrif superchargers. All my precious info went into cyberspace when old d-c.com went down

[golden73]

whats the website address where they sell those centrif superchargers. All my precious info went into cyberspace when old d-c.com went down

I posted a link a few posts before this

Here is a link to the supercharger site: http://www.sd-concepts.com/index.htm

Anyone else care to chime in?

Anyone have suggestions as to which intake manifold to go with? How big of a carb? I was thinking of 850cfm demon.

[Chryco Psycho]

Sorry just been very busy & have notlogged in for a few days
I would use the M1 single plane intake ,you will not suffer with throttle response whne forcing the air /fuel into the engine , I would use at least a 850 carb , we used 2 650s on a 440 & found it was small
9:1 with alum heads is OK , the 440 we built used 8.8:1 with alum & made 725 RWHP 
Valve springs & lifters have to match the cam , the cam should be ground on 112-114 CL I like split profile with more lift & duration  to help the exhaust breath as well as possible , personally I would use a fast ramp CAm like the ultradyne grinds , custom ground with a shorter overlap , you could use 1.6 rockers to get very close to a roller grind without the hassles & cost of using a roller cam

[golden73]

Thanks for the input Neil, should I be looking at a 900 cfm or larger carb then? Which brand would you go with. I have heard great things about the demon carbs.

I was looking at the modified intake option for the M1 intake, from hughes http://www.hughesengines.com/general/intakes/sb_intake.asp

I was thinking that would work great to get more airflow, but do you think its worth the extra $450?

Also, what lifters would you recommend for the harland sharp roller rockers?

Thanks again

[MoparYoungGun]

For a carb I would go with a 950cfm Holley HP.

[Silver R/T]

I ment www.thesuperchargerstore.com they got kits for mopars particularly. i want to go with one of those.
theyve got D1, F1, P1, F1R, F2 with optional intercoolers and power steering relocation kit. Im not sure with which one to go with my 440

[Chryco Psycho]

with the Holley style carbs you can block the power valve & eliminate the surge blowers generally have , you can`t do this with eddy / Carter style carbs
the lightest lifters are the Mopar hollow lifters , comps may be hollow also
wow 450 to do that to an intake !! I can purchase the intake do similar mods & ship it to you for a lot less if you want ... or I should raise my rates

[Mefirst]

Can someone explane the supercharger and how it works for a dumbass like me.. Does it work kinda like a Turbo or is it more like a blower?

Thanks..

/Tom

[firefighter3931]

This car will be taken to the strip, and will see the streets as well. It will not see more than 1000-1500 miles a year. It will need to run on 93 octane though.

The nice thing about blowers is the ability to dial in the boost with a pulley change. A smaller amount of boost will run on pump gas. Then when you want to go to the track, just swap out the pullies and dial in more boost and run race fuel. Personally, i'm not a fan of centrifugal blowers....they can be very difficult to dial in. One guy i know wasted his engine when the carb malfunctioned and went lean. After rebuilding the engine he's still having problems getting it to run properly.

Here's my take on centrifugal superchargers: The induction seems to be the most difficult part to work out. The blower is trying to push air through the carb and that isn't something carbs were designed for. Carburators are designed to work on engine vacuum which pulls air/fuel in from the bottom as opposed to having it forced in from the top.

Roots style blowers have the carb functioning the way it was designed to by pulling from beneath and therein lies the basic difference between a roots blower and a centrifugal blower. Whoever sets up the centrifugal blower has to be "on his game" or there will be problems. Both are effective and both work....one is just harder to dial in than the other....and less forgiving of mistakes.

Ron

[Mefirst]

Thanks Ron for the explanation..

I do think that the roots style blower looks more wicked..

-Is there any difference in what kind of power levels you might reach, in other words, witch blower gives out most power increase?

/Tom

[Blown70]

From my research the Roots type....  At least that is what I have found out. 

[golden73]

I want to go with the centrifugal supercharger because I want to keep everything under the hood. Then after I'm done racing people I can pop the hood and say "yes, that is a smallblock, and yes it is supercharged "

The only down side of the centrifugal type is you have to be around 3000 rpm to develop full boost. That is why I picked out a torque convertor, so when I nail it, I have full boost pushing me along. Roots type develops full boost before 2000 rpms. Yes it does look more bad ass, but what do you do when you get caught in the rain? With a nice centrifugal setup you can keep on cruisin 

Also, centrifugals are easier to intercool, by having it mounted infront of the rad, then the piping up to the supercharger. You can intercool roots type systems as well, but you are lookin at another 6 inches stickin out of the hood.

Ron, why are centrifugal's harder to dial in? I would figure it would be harder to dial in roots. I hope you can give me a little insight here, I'm still learnin my stuff on superchargers.

[Blown70]

I want to go with the centrifugal supercharger because I want to keep everything under the hood. Then after I'm done racing people I can pop the hood and say "yes, that is a smallblock, and yes it is supercharged "

The only down side of the centrifugal type is you have to be around 3000 rpm to develop full boost. That is why I picked out a torque convertor, so when I nail it, I have full boost pushing me along. Roots type develops full boost before 2000 rpms. Yes it does look more bad ass, but what do you do when you get caught in the rain? With a nice centrifugal setup you can keep on cruisin  

Also, centrifugals are easier to intercool, by having it mounted infront of the rad, then the piping up to the supercharger. You can intercool roots type systems as well, but you are lookin at another 6 inches stickin out of the hood.

Ron, why are centrifugal's harder to dial in? I would figure it would be harder to dial in roots. I hope you can give me a little insight here, I'm still learnin my stuff on superchargers.

You are correct on the above.  I do like the idea of keeping it under the hood.  I believe from the above post about shoving the air in rather than pulling the air is the answer to that.  I have however do not know these as good as RON does I am sure.  I have looked at mostly ROOTS type

[firefighter3931]

You are correct on the above.   I do like the idea of keeping it under the hood.   I believe from the above post about shoving the air in rather than pulling the air is the answer to that.   I have however do not know these as good as RON does I am sure.   I have looked at mostly ROOTS type

Blown70, trust me bud....i'm no expert either. The comments i've forwarded are based on feedback i've recieved from other racers. My friend has a roots style 671 on his 68 coronet and i've worked on it with him....in fact we just assembled his engine in my garage a couple of months ago. Some of the componeents are slightly different but by and large a naturally aspirated engine and a forced induction engine are pretty much the same with minor variences in components. Obviously the pistons and rings are different but one area that often gets overlooked is the valvesprings. You need to run more valvespring because the boosted cylinder is fighting the valvetrain....something to consider.

Golden, as stated above....the blow through carbs can be tempermental and difficult to dial in. Have you considered some form of fuel injection ? Maybe consult with the supercharger manufacturer for their opinion.  The points you make are all valid and have merit....the underhood SC is more sanitary and stealth....which makes for a killer "sleeper" combo. The Roots is definately "in your face"....no mistaking what that big lump coming through your hood is for. 

Ron

[firefighter3931]

Thanks Ron for the explanation..

I do think that the roots style blower looks more wicked..

-Is there any difference in what kind of power levels you might reach, in other words, witch blower gives out most power increase?

/Tom

You're welcome Tom. To answer your question ; the roots style are available in different sizes....471/671/871/1071 and so on. The bigger the blower the more boost it will make. There is a point of diminishing returns where overboosting a small blower will generate too much heat and not make any more power. If i were to go the blower route, an 871 would be the choice. You don't need to overdrive it too much to get descent boost and that keeps temps down. The roots style will make more power..... lower in the rpm range. Usually be 1800-2000 rpm you will be developing some boost depending on the pulley arrangement. The carbs are also easier to dial in.

Ron

[golden73]

Converting to fuel injection would be the way to go, but that is too much money for me.  I still need to save up money for all the engine parts, a race prepped tranny, new driveshaft, custom dana 60. Easily over 15k for the driveline. I need to keep the cost down, but without sacrafacing quality.

What would you recommend for a header? I was thinking TTI 2" primary 3" collector.

A lot of the cars using the sd-concept superchargers have huge exhausts, like 4.5"   Is 3" too small for me? I thought it would be better to have a smaller pipe, so you have better velocity. So should I go with a 3.5" or is that overkill?