Iron Vs. Aluminum, the Final say!

[geoffinbc]

Agreed that is a waste of time since the FWD motor into a Fiero is rather painless. If he is on a budget he should just stick with the old motor.

[ericjon262]

i guess it matters the most for fiero guys, who seem to like putting iron heads on aluminum head blocks. Which makes no sense to me.

dingdingding!

Perfect example:

http://60degreev6.com/forum/showthread.php/50788-Decision-help-for-my-Fiero-V6-60

[caffeine]

I guess it matters the most for Fiero guys, who seem to like putting iron heads on aluminum head blocks. Which makes no sense to me.

[geoffinbc]

It really does not matter because iron heads are only used when cost is the major factor in the equation for RWD applications. I would have used aluminum 3500 heads all day long if I had the time and funds to make it happen. But I need my truck back on the road because it was consuming coolant at an alarming rate.

If you have a FWD car then 3X00 heads are a given. There is no point in comparing iron heads because your never going to go backwards.

[ericjon262]

Apples to oranges. I have the luxury of owning a bench, and being able to test different heads on this same bench. Thats the only way to compare anything. Its like telling me milzy gets 290 cfm out of a 3400, or you got 250 out of a 3500. None of that will happen on my bench.

how much $$ to make it happen then.

Dave you have a bench too right?

I've got a set of L44 Fiero heads I will donate to the Cause also, and I should be able to get a set of Gen 2 castings front he J/Y.

I would love to see a side by side same bench comparison between the different heads. just stock flow numbers would be good enough for me.


I am serious.

[SappySE107]

Apples to oranges. I have the luxury of owning a bench, and being able to test different heads on this same bench. Thats the only way to compare anything. Its like telling me milzy gets 290 cfm out of a 3400, or you got 250 out of a 3500. None of that will happen on my bench.

[Superdave]

They'd really need to be measured on the same bench to be completely scientific, pretty neat how the irons are so even on both sides though. That justifies the old single pattern cams a bit more.

[TurboGTU]

3*00 heads outflow SBC heads. The deal with gm recommending them was they can take " duty" better. My guess is overheating, or heat expansion rate. Either way were not dessert racing. Did you cc the chambers curious what they are.
Anyone know if the 3900 heads cc the same?

[ericjon262]

What stage porting are those 3500 heads?

Keep in mind, column 1+2 are stock, 3+4 are ported, and those numbers are the average of 6 ports. for each value.

Flow bench ported, but not by Ben/WOT tech. I told my porter to get me the best numbers he could muster.

[ga2001532]

What stage porting are those 3500 heads?

[ericjon262]

Cliff notes:

stock 3100 and 3400 heads outflow race ported Iron heads by .350" lift, stock 3500 heads do it by .250" lift the data doesn't lie, and it's from multiple sources.


Race Ported "falconer" 2.8/3.4 heads:

Lift      #1 Int    #2 Int
0.100     58.7      58.0
0.200     110.5     110.8
0.300     135.7     138.6
0.400     145.0     142.1
0.500     149.5     151.0
0.600     151.0     152.5

Lift      #1 Exh    #2 Exh
0.100     56.9      58.4
0.200     101.9     100.2
0.300     140.0     138.2
0.400     149.0     152.1
0.500     152.2     153.6
0.600     153.7     153.6

source:
http://www.thirdgen.org/tec...s-falconer-race.html

My 3500 heads.



more flow data here for 3100 and 3400 heads

http://wot-tech.com/shop/gm...ervices/cat_140.html