small block 400

[dragonstyles]

I'm looking into building a small block 400 twin turbo, I went out a few years ago and got a bunch of parts, AFR 210 heads, 286 roller cam, gold race roller rockers and a few other parts. I have now just got the block and now i'm trying to find out what kind of pistons and connecting rods i should use. I am also wondering what kind of intake i should use, i have TPI and would like to keep it that way, but i have heard that it would probably choke out the engine. would that still be true if i were to put twin turbos on it?

[Blake Carstensen]

do you have an aftermarket block? if not I would stop while your ahead. My projected build will be from 500-550 hp and find it will be questionable using the strongest '509' block.

[Blake Carstensen]

here is a great crank compay:

http://www.fastpts.com/hazel-doc/colasbc.html

some scat H beam rods

http://www.scatvw.com/

[dragonstyles]

Its a stock 4bolt main block out of a 77 chevy pickup

[Blake Carstensen]

any stock 400 block should be considered to be replaced with a world products block or something.

crank walking isn't what you need to worry about entirely - thinner block walls are another culprit - this is why you see so many filled with concrete - which takes away from driveability for cooling.

if your going with a twin turbo set up I take it , its a serious build. Do it right the first time - might as well toss those rockers and go with jessel shaft rockers too. I would look at a custom ground cam too.

[Goose]

if your going to turbo the TPI, you'll have to make some wiring harness adjustments and run the code 59 mask - its the ECU mask used by typhoon/syclone and GN's. Its the only way to use a 2 or 3 bar MAP sensor.

[Blake Carstensen]

I'm no guru about the TPI but I dont think its a logical solution to support a twin turbo small block 400 - you might as well put on a TBI on it to get the same performance.

[allpontiacs]

I'd imagine a stock TPI system would choke the hell out of a setup like this. Airflow is key, doesn't matter if you're forcing it in. With an aftermarket intake and throttle body setup I'd imagine it would be just fine. You'll definitely need to fill and girdle the hell out of the block though. Filling the block doesn't really cause any cooling issues, as long as you don't completely fill it. Filling to the freeze plugs is always safe and usually you can fill up to the water pump as well. Heat is only created during combustion and combustion is only taking place at the top of the cylinder. As long as you have coolant flow around the upper part of the water jacket you'll normally be okay

[Goose]

TPI is doable, you'll just be restricted to 5500-6000 rpm or less. using an EFI edelbrock with a throttle plate and elbow would give the most benefits tho.

[Blake Carstensen]

Havent' heard of a turbo build being limited to 5500-6000 rpm - throw the tpi out if you want a turbo build, or throw your turbos out if you want your tpi

[Goose]

I was saying it would be rpm limited with TPI

[dragonstyles]

I have done some reading and alot of people say to change out the tpi for the holly stealth ram intake, would the help with the engine choking out or would it not make much of a difference.

[Blake Carstensen]

yes, holly stealth ram was what I was going to reccomend.

if your trying to throw down some serious numbers - yoru build is going to be as weak as the weakest link.

i'd ditch your cam, rockers, block - i'd also reconsider your heads and go with the 227's

[dragonstyles]

I'm not to worried about throwing down numbers, its my first build and i just want something solid for my first project, then in a few years maybe upgrade.

[Blake Carstensen]

but yes, HSR hands down

[allpontiacs]

If it's your first build forget twin turbos. Build the motor n/a and if you think you'll want more build it strong so you can turbo it in the future

[Blacksunshine]

Building motors is a learned process, not quite like lego's, where you can put all the pieces together and it's fun. There's alot of trial and error for the first timer(no offense), do it simple and go from there.

[dragonstyles]

ya thats what i'm kinda thinking now, but i would like the parts i put in the engine to be compatible for a turbo setup. Or should i just build it N/A and go all out N/A, then if i want to turbo it later just rebuild the engine for a turbo setup.

[Blake Carstensen]

you have good building blocks for a N/A and could easily make 550 plus hp

[89vert]

the tpi would choke at even lower rpm with turbos, the more air through the tpi the sooner it chokes, its more of a cfm thing than a rpm thing,
the faster the air the more "dead" air in the runner, the sooner it chokes

[dragonstyles]

would the stock block and crank be able to withstand 550 hp

[Josh_M]

If you want to twin turbo a fuely motor go for an LS engine...Adams selling some right now ! Slap some larger combustion chamber afrs on it, boost the shit outta it easy 500 horsepower and good gas mileage and weight savings...cant lose

[Blake Carstensen]

would the stock block and crank be able to withstand 550 hp
its a question of reliability

[dragonstyles]

I'm now thinking of just using what i got and get the few major things i need to make it though the next few years, till i can get a new short block that can handle the kind of power i want to get out of it. I'm just going to be using it as a daily driver for now anyways. I just don't want to put everything together and have it blow up in a few months then need to start from scratch again.