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whats the advantages of having aluminum to cast heads? How much hp would you get?

RRT vette

5 hp achieved from the factory.

NitrousSam

Aluminum heads will remove 38 to 42 lbs off the hose of your car. You can run roughly 1 extra point of compression in most cases with aluminum heads and this is the key to making more power without detonation. If you break an iron head in most cases you will have to toss the head...break an aluminum head and you can weld it up and fix it.

90Z51

As a followup to what's above... aluminum heads dissapate heat more quickly, keeping combustion chamber temperatures down, that's why you can usually run a point more compression than a comperable iron headed engine.

ALLT4

Yup, weight and heat reduction.

bogus

the heat reduction has another advantage - less hotspots. Less hot spots, less chance of detonation, too.

All in all, aluminum is better...

qws

Aluminum heads weigh less, however they remove heat quicker which could be good and bad. Iron heads withhold the heat more and you'll get more hp out of the iron heads rather than the aluminum. At least this is what I've been taught.

zoro

They are way easier to port.

Zerski

jcsr72

Theoretically, on paper, iron heads are better due to the more efficient burn inherent to a nice warm combustion chamber. But in the real world, with heat fluctuations and crappy low octane fuel, aluminum is a better bet. And so is losing 40 lbs from your nose.

coupeguy2001

I took off the cast iron heads, and installed GMPP aluminum heads. The end result:
A. runs like 10 degrees cooler
B. gas mileage went up
C. torque went up (don't know how much but you can feel it)
D. no more rocker cover leaks (I used '89 covers-centerbolt)
E. look trick
also, if you use aluminum heads, no matter whose, they lay down flatter with .040 thick head gaskets, and don't seal good with the .015 wafer thin gaskets.
The TPI heads, 89 and later have 58cc combustion chambers. If you have flat top pistons,(mine did) you have to stay with a larger chamber, 64 or larger. If you use the small chambers, you have to use race gas because it will detonate a lot and the knock sensor will pull back the timing so far it won't be any fun to drive.
I have an 86, and when I took off the cast iron heads, I got bump steer because the car was lighter in the nose and sat 1/2 inch higher, making my tie rods not level.
well, i have a friend at the corvette junk yard, and he suggested I use a sway bar off an '84 or a '85 because they aren't hollow.
I didn't believe him and we went over to a stack of sway bars, and he let me hold a hollow bar, then he let me hold a solid bar, (amazed!) the difference was like 30 lbs! so for $40, i got the bar, links and bushings and bolts, installed it with polyeurethane bushings, and all back to normal.
umm now it goes around corners flatter too.

haha anyone wanna buy a hollow sway bar?