What gains and not so much gains do cast iron and aluminum aftermarket heads do? Which one is better for a ATI procharged TPI?

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1992 Camaro RS 3.1L
T5 Manual 5 speed
Cold/RAM air intake
Z-28 Exhaust
8.5mm MSD Ignition wires
TB Coolant bypass

Soon to be a 3.8L turbo RS

AIM screen name - Stopsign696

Kills:

95 (****) Probe GT
94 Mustang GT
91 CRX (dont ask me why he raced me)
2nd Gen Z28 (350) haha to you V8 guys!
1992 RS 305 TBI (good race)
First Gen Integra
More to come

 

Aluminum is 100% the way to go. It can handle a higher compression, which is good for the blower and normally after companies have their better flowing heads cast in aluminum. It's also easier to port aluminum than iron. Oh yea, they also weigh about 50lbs less.

iron is cheaper though.

[This message has been edited by crazeinc (edited December 27, 2000).]

 

Might as well let him know the bad: Aluminum heads are much more likely to warp if you overheat, so you better keep your cooling system in good shape. That and the cost are the only bad points though, if you can afford 'em, get 'em!

 

Aluminum is easier to cross-thread a spark plug. I was "punished" for not being careful with aluminum many years ago on a motorcylce I owned. Torquing is VERY important with aluminum. Very fine line between too little, just right and OOOPS!.

 

Biggest advantage for aluminum is the weight saving. The other reason aluminum heads are used is that they can disipate heat better. A cooler running head can handle higher compression ratios without detonation.
However like the points that everyone else has said already, aluminum has it's drawbacks. Try finding an aluminum headed import engine that doesn't have a warped head after years of use. 30 year old cast iron heads are still being used with no problems if the casting wasn't thin and cracked since then.

Aluminum parts although they are not considered exotic any more are still not designed for high life. I'd rather have a complete cast iron engine that will last 200,000+ miles of daily driving with no problems than an aluminum engine. Aluminum has it's place but don't expect it to survive like cast iron will.

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Stephen's racing page

87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
454 Big Block buildup now in progress for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Altitude corrected rear wheel HP based on power to weight ratio: 476.5
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

 

I'm glad I'm not alone, Stephen.I just bought Dart Iron Eagle 230cc's for my new 383. I friend of mine just freshened up the engine in his 76 Nova, It has Edelbrock RPM heads, and it had never been overheated. We decide to run an indicator across them before we sent them for a valve job,just be sure, and they were warped pretty badly. The machine shop had to cut them .013" to get a consistant flat surface. If this happens a few more times, he'll have to cut the intake to get a seal. There are some definite advantages to aluminum, but the heads on my car now are '74 smog heads--ported w/ good valves and springs, and my car runs 12.50's. I ported the Darts, and sent to them to be flowbenched and angle-milled. They flowed 298@.600"intake, and 208@.600"exhaust at 25"H20.These are some killer flow #'s that really impressed me. I chose these heads for cost, durability, and performance. I have seen guys race double humps for decades and run well, so I bought in hopes in that I wouldn't have to buy a new set of heads for a while.

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82 Z28 350, Ported #882 Heads, Performer RPM cam and intake, hedman headers,650 Demon carb,
Trans: Turbo 350 w/ 4000 stall -- Rearend 7.5 w/ Richmond 4.10's, Auburn Minispool
Future plans: Dart headed, Roller cammed 383 in early '01


89 RS, L03 305, Hypertech Chip,cat delete, Dynomax exhaust,K&N open element Filter,160 stat, MSD coil --Trans:700R4 Corvette Servo -- Rearend: 7.5 GM 3.42 w/ posi-lock
http://www.bassettracing.cz28.com