My 408 supercharged stroker build

[firefighter3931]

The biggest header TTI makes for a stock style smallblock head is a 15/8-13/4 step header with a 3inch collector. A full 3in x-pipe exhaust system with some high flow (dynomax ultraflow) mufflers should be sufficient.

Ron

[Blown70]

Ron ohh yes, I have heard much in my seach about valve springs.  I have spoken to Tim at FHO and Ray Barton Racing, and Mopar Engines west(?).  I am very happy I have contacted all of these people for advice.  I was going to run and 8/71 now according to almost everyone I will be running a 10/71.  I also have a friend who races 410 sprints and I would on running an overdrive of the blower have a pretty good final compression Ratio.... and his runs pretty high so that has even helped understand the Valve gear more.

Sorry to highjack the thread  Golden73

My understanding is esp. with a Supercharger you really need to let the engine flow esp. exhaust.  So I would get the largest combo that would work well....

[Mefirst]

This was a very helpfull and enlightening thread.. Thanks guys 

/Tom

[CFMopar]

With a little fabricating could you not just rig something up so that the carb sat on top of the air box wiht a centrifugal?

[Silver R/T]

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

many racers prefer centrifigular over roots, cause its not mean look of the roots blower sticking out. but centrifugular has more options over roots. Centrif will also make more power in upper rpms than roots if dialed in correctly. I would take centrifigular 44o over roots, especially for highway racing/track 1/4 race.

[sandmbmx88]

Vortec S trims and A trims are easy to find from 5.0's just adapt it to what you need it for. An A trim will max out at 10 lbs an S trim can go alittle higher. if i where you i would get a magnum 360 and do that same build but with R/T iron heads. Ive though about this setup before. plus this way you can run the late model injector setup with a stand alone and scrape somemore hp out of it.

[golden73]

Vortec S trims and A trims are easy to find from 5.0's just adapt it to what you need it for. An A trim will max out at 10 lbs an S trim can go alittle higher. if i where you i would get a magnum 360 and do that same build but with R/T iron heads. Ive though about this setup before. plus this way you can run the late model injector setup with a stand alone and scrape somemore hp out of it.

Eh, I would rather stick to the stuff I know. It sounds hard to map FI, which means more $$

I will be satisfied with the power the engine will put out, and thats enough for now.

[Blown70]

many racers prefer centrifigular over roots, cause its not mean look of the roots blower sticking out. but centrifugular has more options over roots. Centrif will also make more power in upper rpms than roots if dialed in correctly. I would take centrifigular 44o over roots, especially for highway racing/track 1/4 race.

I will say with what I know about Roots type I will disagree with this statement.  I do not know A LOT about the centrifugal but, I know enough about the roots to disagree witht his statement...

[golden73]

many racers prefer centrifigular over roots, cause its not mean look of the roots blower sticking out. but centrifugular has more options over roots. Centrif will also make more power in upper rpms than roots if dialed in correctly. I would take centrifigular 44o over roots, especially for highway racing/track 1/4 race.

I will say with what I know about Roots type I will disagree with this statement.   I do not know A LOT about the centrifugal but, I know enough about the roots to disagree witht his statement...

I would agree with you blown 70

Look at top fuel dragsters for example

[Blown70]

well golden vailid points will be had on both side I have no doubt.  I would say it matters who is tuning.

TOP FUEL well that is a strict race application.... which makes the discussion harry to say the least.

Understand I have no issues with these types.... I just like the look of a ROOTS type.

However, what you have will be sweet when done.   

[kamkuda]

Accurate fuel metering is very important and why fuel injection is often recommended.  Even if you decide to run a carb, you will need a blower card (read not cheap) Also budget for a LM1 a/f meter or something similar so that you can tune and to ensure you do not go lean.  You should also look at a MSD 9 series ignition system to help

A friend has a stroked 383 procharger set-up (SD concepts package).  The block is signicantly reinforced on the bottom end.  He hope for 9's but has had loads of fun, melting parts, rebuliding parts and trying to tune this beast.  They are far less forgiving if you don't have it tuned correctly and it seems not that easy to do without fuel injection. Yet I went for a ride.  It is pretty wild.

[golden73]

Accurate fuel metering is very important and why fuel injection is often recommended.   Even if you decide to run a carb, you will need a blower card (read not cheap) Also budget for a LM1 a/f meter or something similar so that you can tune and to ensure you do not go lean.   You should also look at a MSD 9 series ignition system to help

A friend has a stroked 383 procharger set-up (SD concepts package).   The block is signicantly reinforced on the bottom end.   He hope for 9's but has had loads of fun, melting parts, rebuliding parts and trying to tune this beast.   They are far less forgiving if you don't have it tuned correctly and it seems not that easy to do without fuel injection. Yet I went for a ride.   It is pretty wild.

Sounds like a wicked ride. I will be going EFI eventually. Just not in the budget right now 

[kamkuda]

Here is a picture for you, just for fun.  The hat is different now.

[IllCharger]

Very good info in this tread.  I plan on going this route too (440 with a roots blower).  I like the look of a roots as well.

[golden73]

Here is a picture for you, just for fun.   The hat is different now.

Mmmmm, thats a nice looking engine   

Has your friend had any problems with pulley's breaking?

[kamkuda]

No problems with pulleys that he has told me.  And he made his own brackets.

[Rayzor]

Seems kinda late to make any sort of reply here, But I have a SD concepts package for a 440. I would recomend fuel injection be part of the total plan package rather then a after thought. If budget is a concern you can sorce together a throttle body setup from say a mid 90s GM truck and have Howell EFI or mega squirt help you with the dial in. I ran a twin turbo slant 6 for awhile with both modified Holley and dual webbers. Fuel metering was a nightmare to say the least. It seemed for every improvment in one area it would be completly off in another. While I have yet to run the 440 with the compressor, I have since hung a P trim procharger on the slant with tbi. The power difference is way better and the constant lean/rich conditions are gone. On another note, I am running 8 pounds of boost on top 9.2 compression  cast pistons. Running a innercooled blow threw setup has the advantage of keeping the air charge way cooler then a roots type compressor. That helps keep the pre ignition under control. Both compressors  have there pros and cons But personaly I think the roots are a better race unit then for a streeter.

[golden73]

Thanks for your input... I have decided to go the injection route, although I do not know which kit I am going to get yet. I am leaning towards the force-efi. This is definately going to be an expensive build, but well worth it