This is topic Aluminum heads vs. iron heads? in forum Tech Talk at Northern California Ford Owners  .


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Posted by Yung Than (Member # 728) on :
 
-I was wondering how much weight can I expect to save with aluminum heads on a 5.0 over GT40p iron heads?
-Which are the lightest street legal aluminum heads?
-Also, are iron heads better for specific power combos or applications?
 
Posted by Black94 5.0 (Member # 655) on :
 
Aluminum heads each are about 20-25lbs lighter than stock cast iron heads...

[ December 31, 2002, 03:40 PM: Message edited by: Black94 5.0 ]
 
Posted by st5150 (Member # 51) on :
 
It all depends on what combo you're looking to run. There aren't many iron heads for you to choose from for small block fords.
 
Posted by shade-tree (Member # 298) on :
 
GT-40/GT-40P iron heads out of the box are worth about 0.3 in ET and 3 mph in a properly driven bolt-on 5 liter.

Windsor Jr/Windsor Sr. are a step above this (though the Windsor Sr. is probably a little big for a street 5.0)

Aluminum heads will save you roughly 45 lbs. off the front of your car. They're all roughly the same weight, just a big 'ol slab of aluminum.

aluminum heads require less effort to port than iron (more ductile) and can typically support more timing than iron due to it's superior heat dissaption.
This very advantage becomes a disadvantage though on a high compression motor, the iron head is better able to retain heat and will have a greater volumetric effeciency than it's aluminum counterpart simply because it doesn't bleed off as much heat.
 
Posted by Yung Than (Member # 728) on :
 
Thanks for the info.
 
Posted by Pro50Eric (Member # 2065) on :
 
For a street car pick iron. Iron will always make more power than aluminum. Especially in a heavy car. When aluminum gets hot it expands which kills hp. Only way you need to go aluminum is if your wanting to save weight.
 
Posted by Yung Than (Member # 728) on :
 
So would iron be good for a 10.5:1,331 stroker with a 8psi Vortech? I still haven't decided between that or a 8.5:1, DSS 306 with a 15psi Vortech with aluminum heads maybe? Which of the combo's above is more reliable and less likely to detonate? Which would make more hp?

[ January 01, 2003, 11:19 AM: Message edited by: Yung Than ]
 
Posted by SIR OneSlowPlitBumperonN2O& I'm gay (Member # 1708) on :
 
quote:
Originally posted by Yung Than:
So would iron be good for a 10.5:1,331 stroker with a 8psi Vortech? I still haven't decided between that or a 8.5:1, DSS 306 with a 15psi Vortech with aluminum heads maybe? Which of the combo's above is more reliable and less likely to detonate? Which would make more hp?
A 9:1 motor will make more power with iron heads than a 9:1 motor with alum heads because of what he just said BUT. A 10.5:1 motor with iron heads will make LESS power than a 10.5:1 motor with alum heads because, unless you're putting in race gas, you'll need to back off some timing with the iron head motor in order to keep it from detonating. Aluminum dissipates heat faster, which suppresses detonation.

samething for any power adder, use alum heads, use more timing, make more power.

Lastly, it might be hard finding an iron head that flows as much as an alum head.

[ January 01, 2003, 02:49 PM: Message edited by: SIR OneSlowPlitBumperonN2O& I'm gay ]
 
Posted by boosted89Saleen (Member # 2243) on :
 
[/QUOTE]A 9:1 motor will make more power with iron heads than a 9:1 motor with alum heads because of what he just said [/QB][/QUOTE]

So GT-40 heads are gonna put out more HP then a motor with say AFR heads? [BS flag]
 
Posted by Jeff S (Member # 371) on :
 
quote:
Originally posted by boosted89Saleen:
So GT-40 heads are gonna put out more HP then a motor with say AFR heads? [BS flag]
No. However if there were two identical versions of the AFR head, one aluminum and one iron, the iron version would make more power.

[ January 01, 2003, 05:33 PM: Message edited by: Jeff S ]
 
Posted by shade-tree (Member # 298) on :
 
Windsor Sr's are a pretty high flowing iron head, available quite cheap used.

'course I think they're on the big side for a little EFI 302 though.
 
Posted by SIR Paint Job w/ '84 Tercel on MTBE (Member # 1708) on :
 
Thank you Jeff, I thought that it was obvious I meant on heads with equal flow #s. Especially since I went on to mention that it's hard to find an iron head that'll flow what some alum heads flow.

shade-tree, If you buzzed that little 302 to 10,000 rpm then I'm thinking the Windsor Sr might be a little too small up top. It all depends on the combo.
 




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