Is Aluminum or Cast Iron better for Turbochargine?

[nova]

OK heres the deal.

In about a year I will probably be coming into a decent amount of money ($1500-$2500 per month) just to play with, none being needed for living expenses. I'm trying to develop a long term plan for my car that includes building an engine from a bare block on up to be used with a custom twin turbo setup.

What I want to know is which material works better for turbos for both the block and cylinder heads?

I have a friend who knows a lot about turbos having built several custom setups and he says aluminum is better for both but I've done some reading and a fair portion of the sources I've read have said cast iron is better. What is everybody's input on this matter?

Any help is appreciated. [img]graemlins/burnout.gif[/img] [img]smile.gif[/img]

[camaro_zach]

I always thought aluminum was better period...i could stand corrected though.

[nova]

Come on there has to be more input than that.

[Patrick Javert]

Alluminum is better for the heads, but you will want inconel exhaust valves so heat energy isn't soaked up. Inconel is one of the best things you can use to contain heat energy. If possible, have 2 custom exhaust manifolds made out of inconel and the turbo exhaust housing(s) made of inconel. your turbo will spool a little faster and you may be able to pass smog easier. Also, if you plan to twin-turbo, get 2 ls1 high flow cats to put directly after the turbos to make the most of the heated exhaust and pass smog.

[nova]

<blockquote>quote:</font><hr>Originally posted by Patrick Javert:
Alluminum is better for the heads, but you will want inconel exhaust valves so heat energy isn't soaked up. Inconel is one of the best things you can use to contain heat energy. If possible, have 2 custom exhaust manifolds made out of inconel and the turbo exhaust housing(s) made of inconel. your turbo will spool a little faster and you may be able to pass smog easier. Also, if you plan to twin-turbo, get 2 ls1 high flow cats to put directly after the turbos to make the most of the heated exhaust and pass smog.<hr></blockquote>

I'm not really worried about emissions tests. Nobody cares about emissions where I live. ;)

So let me make sure I have this straight.
Aluminum heads
Iconel exhaust valves
Iconel manifolds and exhaust housings

What about the block? GM makes an aluminum 60 degree V6 block and I'm wondering if it is what I need or if it is overkill. Will a normal cast iron block work just as well?

[Mighty Thor]

There's a good discussion on this on Hot Rod or Chevy mag.. don't remember. But cast iron is way better than aluminum becuase it is stronger and have more potential than aluminum that can bend and scratch. It's a really good article.

But aluminum is lighter and breathes better though.

[Shirl]

Yeah, I was just about to say that I would think Iron would be much stronger than aluminum (although, aluminum would be lighter).. Personally, I'd take the extra weight for durability.

[WickEdSix9838]

an iron block and aluminum heads, you dont need to shell out a crap-load of money for an aluminum block, its a waste for what your gonna do, and if you can get aluminum heads, they are lighter and can be fixed much easier if you ever hurt the motor, also if the heads are ported, aluminum is a lot easier to deal with!!

[nova]

Ok. Thats what I needed to know. That makes things a lot easier. Those 60 degree aluminum blocks are 3 times what I can get a cast iron block for.

Cast iron block
Aluminum heads
Iconel Valves
Iconel Exhaust manifolds

Thanks guys.