1: Fenderwell cold-air induction.
2: FMS 1 5/8" unequal length headers.
3: Flowmaster 3-chamber cat-back.
4: 180* stat and 3-row radiator.

I'm thinkin' I need to get some more air into and through my engine. To that end, my thought was a 65mm throttle body and EGR plate, port-matching my stock intake manifold and (the main subject of this post) improved cylinder heads. I hear all the hullabaloo about aluminum heads: AFS this and Canfield that. In talking to people I know that work on high-performance motors professionally, I'm not sure that aluminium heads are the way to go for a street car. Are there any benefits inherent in aluminum heads versus iron? I can buy iron heads with the same size valves for 2/3 the price of aluminum and I can have my heads reworked for half the price. Anybody have any input, suggestions or ideas?

Thanks,

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Dave

1) Weight;
2) Heat transfer capabilities.

Now, any car can benefit from a bit of weight reduction, especially over the front wheels of our Fox Mustangs (and a convertible, to boot!!). You are probably saving about 50 pounds over iron heads, which while is not an insignificant amount, you won't exactly be noticing huge differences in a street driven car. To some it's worth it to gain that extra 0.05 sec. at the track, but for most of us we wouldn't really notice it on the street.

Heat transfer becomes a big issue if you are thinking of running a blower. Heat is your enemy with any forced induction system. Heat leads to detonation, and detonation leads to all sorts of nasty things. On a N/A car you aren't elevating the combustion chamber temperatures to the levels of a forced ind. car, so heat isn't as much of a problem. You can still run more timing advance than stock on a modified N/A car using pump gas and not have to worry much (providing you keep it reasonable). Once again, for racers this can still be an issue. Aluminum heads allow them to extract that little extra out of the engine that may help trip that win light, which is the whole point. For a street N/A car, it shouldn't be tuned to run within an inch of exploding, so there isn't as much of a need for that little bit "extra".

Some of the new aluminum heads are really advancing in terms of flow numbers right out of the box. The aftermarket has really boomed on the Al. heads, as that's where the big $$ are. However, you can take a nice set of iron GT-40 heads, or Windsor Jr./Sr. heads and get comparable flow numbers with a good port job, at quite a bit less cost.

So, what does all this mean?? For me I would say if you are going to be adding a blower at any point I would bite the bullet and step up to a set of good aluminum heads. In the end that would be the wisest choice to get maximum performance and minimum chance of having problems with detonation (well, that and a good ignition and BTM system). For a street driven N/A car that is not a regular strip stormer, and whos owner jsut wants better performance out of his combo for minimal cash outlay I would go with a set of ported irons and use the extra cash for a Cobra/equivalent aftermarket intake/MAF/TB set up.

Just my $0.02!

Regarding the intake Ian, I'd kind of like to stay stock looking for a stealthy kind of look. Anybody have any input on port-matching the intake?

quote:

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Originally posted by wythors:
As an aside, does anybody have any opinion on Edelbrock Performer heads? If I go aluminum, I can get a screaming deal on them through one of my suppliers.

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Ummm, Dave? Can that deal include internet buddies?