Me and my g/f are in the process of researching and mapping out the plans for the 383 TPI I plan on building from the ground up. The first thing we are about to buy is the engine block, and an engine stand of course =).

I want to do everything outta aluminuim. I know its a lot more expensive, but I am going to be replacing all the panels on the car with fiberglass panels and trying to really lighten the car up.

Now I've heard aluminuim is bad in some cases cuase it releases heat to quickly if you are building a 12 sec car. So would an all aluminuim engine be a bad thing or a good thing?

Or should i get an cast iron block with aluminium heads and intake and what not??

Also, is the LT1 all aluminuim or just the heads??

 

LT1...just the heads.

If all you want is a 12 second car, then the all aluminum idea is overkill. If you want a car that does 11s or better, can run 180, and corner like its on rails, then the all aluminum is a good idea.

My $.02

 

All aluminum block is overkill IMO

If you wanna go that route I'd seriously drop in an LS1, with your car as light as you're trying to make it an almost stock LS1 would drop you into 12's.

I'd otherwise run one of those high nitride SBC blocks from (70's?) they were a bit lighter, and stronger, aluminum heads DEFFINATLY shave weight, yea you loose heat but there's also a point where you NEED to get rid of heat (blow engines)

 

Aluminum block will cost you a mint, and is certainly not worth the expense for a street car. Aluminum heads, intake, water pump and mini-starter can shave quite a bit of weight off the already fairly light small block Chevy without breaking the bank.

BTW- a lot of the heat rejection of an engine happens in the heads and there are MANY MANY aluminum-headed small blocks running around without cooling problems, for what it's worth. I wouldn't worry too much about overheating problems.

Remember- INCREASING HORSEPOWER COSTS A LOT LESS THAN TAKING WEIGHT OUT OF A CAR.

 

You misunderstand the aluminum problem with heat

Its about the thermal properties of the materials used. The idea of combustion is to retain as much heat (power) within the combustion chamber as possible, then expell as much heat out the exhaust as possible (thats why the big boys run thermal sensors at the track) more heat = more power. Cast iron will retain this heat (power) longer/easier/better. Aluminum will expell it and allow it to travel outside of the combustion chamber thus theoretically lowering power. Now the point is brougth up that "why do aluminum aftermarket heads make better power" this is realized instantly once you take a look down an intake port, cast iron doesnt "cast" as easy as aluminum, aluminum comes out very clean cast, and on top of that ports emenslly well, and then there's the step beyond, AFR's, these heads are CNC ported on a 5 axis machine, something a bit more difficult again with cast, so they flow like a muthah, but assuming the ports were identical on two given heads, one cast, one aluminum, the theory is that cast would make more power due to keeping the heat where it belongs.


The overheating issue with aluminum is that if it DOES over heat aluminum will warp easier, which is obvious the side effects that would have.

 

CHP did an article that actually proved Iron heads flow better than aluminuim heads....

But to the topic, after doing some reading for the past hour and looking at costs of all aluminuim blocks, I think I'll find an cast iron block instead. Probably a world product, I've heard good things about them.

Mostly a street car, dont' really plan on running at the track alot, but I did want to make the car ligther.

Thanks for imput guys

 

GMPP has a good selection of iron and aluminum SBC cases, and the prices aren't too bad if you shop around.

 

I wouldn't spend your money on aluminum block. if you only want 12's don't spend the money. I plan on getting one for my camaro but I'm hoping for low 9's with it. so I somewaht need it. but if I were you I sure wouldn't buy one