Ace_Murdock

i was looking in jegs, and i saw these heads. they are designed for 400+ small blocks. with a 220cc intake port, a 68cc exhaust port. 2.08" intake and 1.60" exhaust. and a 64cc or 72cc option.

more info here:
http://www.worldcastings.com/tech/motown200.pdf

how would turbochargers like these heads for a 400 small block?

is the I/E ratio about right?

what else is nice about these, is that they are cheap $469.99 iron and $484.00 a peace in jegs.

later

andrew

89ProchargedROC

220 is too big in my opinion.....get something around 200-215 and port it a little bigger. It will be better

PETE

iTrader: (1)

Depends on how much boost you will be running 220 will flow some serious air so you better have the right cam to keep the valves open to ingest it. If you plan on running 15+psi they'd be killer if you're gonna go with 10 psi max go with 200's....

89ProchargedROC

the flow difference isn't going to be as big as you might expect. if you got some 200s and spent some bucks on a good porter and he ported them out to maybe 215...they'll flow better than the 220s stock

Ace_Murdock

ok so what are some heads that can do give me the flow for about the same price?

Ace_Murdock

or what if i were to increase my engines displacement to about 415"?

89ProchargedROC

the bigger the cubes of the engine, the more intake port you can have at an un-boosted state without suffering a loss of response or torque.

Ace_Murdock

so what does this mean for a turbocharged application?

i have an offenhauser dual quad intake that will be able to flow enough for these heads as well.

PETE

iTrader: (1)

A 415 will need those heads(to say the least). Plus by stretching it that far the production block is at a disadvantage. I would stick to a 30 over 400 with good 4 bolt caps, a set of ported afr 195's(I like the smaller port volumes to keep the velocity high on a street motor). It'll benefit you three ways.

1. you don't have to go to a huge cam.
2.TC can be more streetable(in an auto setup).
3. The port work will give you a little more volume and you won't have to run sky rocket boost to get the same flow.

daverr

iTrader: (1)

i have the exact same type heads on my engine.Its a 350 .060 over.i do not run into any throttle response problems at all.i also run a 294s comp cams(246 at .050 and .525 lift).i do admit i need a bigger cam(bigger solid or solid roller) for this 13-1 motor.its still pretty streetable my power brakes still work.These head probably would work better on a 400(pump gas street motor), as for my 350 i have no driveablity problems with my setup(race gas,more strip then street). try sportsman II.

dave

Ace_Murdock

are the sportsman II heads aluminum? how big are the valves on those heads as well? the aluminum heads are pretty close on price with the sportsman II heads.

83 Crossfire TA

iTrader: (2)

How much flow you need for an engine almost entirely depends on displacement and RPM (how high you plan on winding it and possibly where you want the torque peak). Once the ports flow what the engine could realistically injest, larger ports don’t do much of anything, mostly just hurt velocity and limit your low and possibly midrange.

So basically, in a perfect world you want to choose the smallest head that flows just enough for the power you want to make

Adding boost doesn’t change this (if anything, it’s less important to get big enough heads), as a matter of fact, if the heads flow enough for what the engine can do NA, they will always flow enough under boost, since the volume of air and volumetric efficiency don’t change, the density just goes up, which increases mass flow.

Ace_Murdock

well honestly i don't quite know how high i will need to wind the motor, but playing with desktop dyno2000, the engine's trend is to make peak power near 6500-6800 rpms. and of course i don't really know how close this will be to reality.

i have no problems reving 400s, all of the guys running 400s in their stock cars hit the 7000 rev limiter in the straights, lap after lap night after night.

the engine will be mated to a t56 and tall gears in the rear, so the car will be rev happy anyway.