Building a motor questions:

[OrangeMustangGt]

If i build a motor, would it be cheaper to get a 347 stroker kit, or say get a short block. Also, what is a good blower compression, for say like 20lbs boost? and last, what id the difference between forged and hypercrutic pistons. Also, could i get some "low compression pistons" and put them in my stock crank, block, etc with some good connectiog rods, and put some good amounts of boost through it? thanks!

 

[Joes95GT]

To run 20 pounds of boost through any set up requires top of the line everything, starting with the engine block. The block alone will cost you 2500, plus machine work. Pistons, rods and a crank that can with stand 20 pounds of boost will have to be forged and would probably cost another 3 grand. Then heads to flow the 20 pounds of boost will cost another 3 grand once you score up the head bolts and gaskets. The supercharger will cost you another 4 grand plus all the other supporting mods. You are looking at a 25,000 dollar project. Anyway, back on topic...

You would need 8:1 pistons, and they would have to be forged. The forging process is obviously what makes something "forged". They in effect crush the metal, and squeeze it and squeeze it under astronomical pressures to make it as strong as possible. Forged internals are much heavier than hypereutectic pistons which make them much more reliable than the others.

Joe

 

[ChewiesDad]

I agree. Performance rebuild dosen't deserve hyperucraptic anything. Forged isn't a whole lot more unless you go custom or high end.
8:1 is right for a blower. 20 pounds will send your crank to the pavement in a stock block before too long.

Stick with the 347 n/a...by itself with the right parts, it can be a powerhouse. Unless of course, you have the budget for that Renegade class project you're thinking of.

 

[OrangeMustangGt]

lol, no, my plans are basically this: i will run my stock motor as-is with say a 100shot of nitrous, it should last a bit, meanwhile, start building a motor seperate, slowly putting on parts over time, just i want something badass, and i will pay slowly, so money wont be a huge problem. Basically, i maby i wont run that much boost, but im loooking for say 400-450-500 hp, etc and nothing for a drag strip, just street, i guess i should get maby just a good 302 shortblock, and get say a 12 or so lb blower? but my main problem is finding what compressions are compatable with certain levels of boost, as this will effect what short block, or piston kit i will need, and also, to stay with forged internals, anyone know of some good companys that sell strong shortblocks set up for some boost? thanks

 

[red94fiveo]

I don't think you're going to need to see 20pounds of boost for 500 rwhp? If you run a good 331 or 347 with a solid H/C/I, you should be able to see at least 500 RWHP from a blower or turbo.
DSS racing sells some good short and long blocks. Their quality is supposed to be first rate, and their prices are pretty good. MIght want to look at them, they have low comp available for just about anything.

 

[Joes95GT]

lol, no, my plans are basically this: i will run my stock motor as-is with say a 100shot of nitrous, it should last a bit, meanwhile, start building a motor seperate, slowly putting on parts over time, just i want something badass, and i will pay slowly, so money wont be a huge problem. Basically, i maby i wont run that much boost, but im loooking for say 400-450-500 hp, etc and nothing for a drag strip, just street, i guess i should get maby just a good 302 shortblock, and get say a 12 or so lb blower? but my main problem is finding what compressions are compatable with certain levels of boost, as this will effect what short block, or piston kit i will need, and also, to stay with forged internals, anyone know of some good companys that sell strong shortblocks set up for some boost? thanks

If your looking for somewhere in the neighborhood of 400-500 RWHP, get a nice set of aluminum cylinder heads, a nice cam, a good flowing intake and put a Paxton or Vortech on it. It would be a good idea to have the block girdled, and that will make it strong enough to support that power, as long as you aren't drag racing and relying on all 500 horsepower all the time.

Joe

 

[OrangeMustangGt]

do i need low comp for say 12 lbs of boost?

 

[Joes95GT]

No, our compression is low enough to run 12 pounds of boost and pump gas. You will have to run 93, but that is a given. I believe our cars are only 9.0:1. Just make sure you have more than enough fuel. You can roach a piston in an instant.

Joe

 

[yellow1995Cobra]

lol, no, my plans are basically this: i will run my stock motor as-is with say a 100shot of nitrous, it should last a bit, meanwhile, start building a motor seperate, slowly putting on parts over time, just i want something badass, and i will pay slowly, so money wont be a huge problem. Basically, i maby i wont run that much boost, but im loooking for say 400-450-500 hp, etc and nothing for a drag strip, just street, i guess i should get maby just a good 302 shortblock, and get say a 12 or so lb blower? but my main problem is finding what compressions are compatable with certain levels of boost, as this will effect what short block, or piston kit i will need, and also, to stay with forged internals, anyone know of some good companys that sell strong shortblocks set up for some boost? thanks

As was stated,You will not need 20 pounds of boost for 400-500hp. Also, do you realize how much money its really gonna cost for an engine like that? Your tranny is gonna need to be upgraded, rear end upgraded, clutch, amongst many other things. Then you will start breaking things often, thats when it get REALLY expensive. I think you should start off like the rest of us, and go with a nice set of heads, a cam and intake.. Then work your way up from there.

The stock compression ratio will be fine with 12lbs of boost.. You could even go 9.5-1. I guess it depends on the blower you go with. The cooler the intake charge the better.