ok so i picked up a b&m supercharger for a big block today for a good price couldnt refuse it. i was going to build a small block but i will put that on hold. im going to build a big block and what specs can i do to give me 700hp

 

dayyyyyummm thats nice Keep us posted on your progress i have to see the finishing results.

 

Which supercharger is that?
What BBC parts do you have thus far?

 

no parts yet, but money in hand to buy some. i have a 454 block.

its the b&m 174 i think.

 

does this sound descent for my setup?

652HP @ 6000RPM HP
647TQ @ 4000RPM TQ

454 stroked and bored to 496
dart 345cc heads
xr 280 cam 242/248 .646/.653 - 1.8 rockers = .684/.691
b&m 142 roots blower

 

That blower might be a little small to move enough air for 700 HP.

 

a supercharger that small will die out at high rpms. Be sure to get a good supercharger cam, good porting on your heads, and I'd add nitrous on top of it. I used to have a 144 supercharger on my small block, a blower that small will spew out some hot air at the top of your power band, nitrous, even 100 shot will drastically help, plus it'll be hard to hit 700 without it. And don't forget a smaller pulley on the super and/or a bigger crank pulley for some more boost

 

i think i made a descent setup above your post.

 

those heads are way too big for that application, they will flow to around 8000 rpm. The cam ends at 6500, and the supercharger will start becoming innefficient at 5500 max. Superchargers like cams with normal to higher lobe separation too. With a roots blower, you will be getting max boost right when you floor it, and since your supercharger is so small, you cant turn the rpms that high anyways. As I said before, nitrous will help with upper rpms, so will water or meth injection. Pick out a combo to run to 6000-6500 max, and do your research first. A desktop dyno is a good place to start, but don't make it your bible

 

is it ok to spin a blower to 6000RPM? that is what my peak power is according to desktop dyno. 650HP @ 6000RPM

 

Although I'd have to build another engine for a blower because mine has too much compression, I wouldn't mind one. A 6-71 blower would be small for me. I'd want at least an 8-71 on my engine.

For a street engine, that blower would do good but I doubt it would make 700 HP at any usable RPM. Trying to overdrive it to make more boost also builds a lot more heat. It's better to use a bigger blower to build boost because it will flow more air without having to spin faster.

 

I know they make some kind of intercooler for whipple superchargers that mounts between the manifold and the supercharger I think it is cooled by water. You might be able to get something like that and run more boost?

Here is a link for what I am talking about http://www.whipplesuperchargers.com/...sp?ProdID=1158

 

There's a local street legal Ford Fairlane with a cooler like that under his big roots blower. The blower sits about 6" higher out of the hood. Your cooling system is running around 180*. That's a lot colder than the 300+ that the blower is pushing into the engine so the coolant will bring the temperature down a bit. You also need an upgraded cooling system to remove all that excess heat.

The whipple cooler is designed for boats. You're not using the engine's cooling system to lower the temperature of the air charge.

Here's what I want for an engine. Sorry it's a little dark. It was converted from a MOV file. I can actually buy this engine for $10,500 complete. 10-71 high helix blower on a 454.

http://tinyurl.com/28ruuo

 

so this setup is no good? what if i got smaller heads and ported them?

 

I just love the picture. It's sitting on the bed, with the laptop in the foreground.
Somewhere in there is a good wife ...

 

Power adders don't need huge ported heads because the air is being forced through the ports. My 540 engine only has unported 310cc heads. Some 345's would be nice but I don't really need them.

Same with cam profile. A blower cam doesn't need the same kind of grind as a NA engine because the air is being forced past the valves instead of being sucked past them by the piston moving down in the cylinder. As the valve starts to open, there's boost pressure behind it waiting for it to open. A blower grind depends more on LSA and overlap than it does on lift and duration.

 

so a smaller set of heads sounds alright, what a different cam i need something with more LSA and less lift?

 

345cc heads are way too big.. a set of AFR 315cc would be more than enough..

http://airflowresearch.com/articles/article071/A-P1.htm

 

alright even if i cant get anywhere near 700 Horsepower, id like to see that much torque.

i dont want to hurt the blower by trying to push out as much as i can for horsepowr.

 

With a big block, you could get 700 HP N/A more easily than you could by choking it with that weenie little blower.

 

Dude there was this article in carcraft a few years ago i have the mag it was called "import killer, 950hp from a 7.4L". heres the interent link http://www.carcraft.com/projectbuild..._up/index.html

 

ok so i wanna start ordering parts i just ordered a 9" rearend for my car. here is a list of the motor i am thinking of.

608HP @ 5500-6000RPM
675TQ @ 3000-3500RPM

454 stroked to 496
dart 310cc heads
Crane ZHR-296-2S-12 IG hydraulic roller .610/.632 234/242
b&m roots blower (think 144)

i was thinkin of adding a shot of nitrous when i run at the track to keep the blower cool like stated above.

what do you guys think of this setup?

 

stephen it's all in how you look at it. even N/A the air is being pushed past the valves by pressure. atmosphere is 14.7psi which pushes that air past the valves. you run 6pounds of boost you now have 20.7psi pushing past the valves.
even works the other way with the boost being sucked since the piston still makes a low pressure zone.