iron head motors are not dead

[rx191]

the iron head v6's are good motors if you know what you are doing the heads on these motor can flow as high as 235CFM witch is engough to support 300HP NA. the problem with these motors is the intakes, the injected ones only have enough flow to suport 180HP and thats with the 3.4 manifold from a camaro. and the stock carb intakes is only good to about 140HP. these motors are goo engines but need some basic mods to help them out. porting the bowls on the heads help improve flow alot as does gasket matching, a little larger valve doesn't hurt either, also you can run 1.7 ratio rockers on these motors pretty easy. guide plates are easy to install and hardened pushrods can be found without much problem. all you guys seem to think that the gen2-3 engine are the only way to go but you can make very good power with the old iron head gen 1 engines it just takes a little more work

[Doubt_Incarnate]

quite a few of us have iron heads. my car came with them, and im probly gonna stay with them since i dont want to change all the connectors under my hood (<----lazy). the aluminum heads just outflow the iron ones, and flow is power. and as you mentioned the intakes for the iron heads suck, so thats another plus for the aluminums, when the 3x00 popped out they brought a massivly improved intake with them, and a better block with roller cam and improved oiling. most 660's are fwd, and most of those are aluminm heads, they are just everywhere now.

i'm most likely re-starting my project 3.1 with iron heads for bolt in ease, and with the 3.1 iron heads advertised 8.5:1cr i'll have room for boost later.

i think its 614streets with a feagol supercharged iron headed 3.2L. curtis with his turboz24 has iron heads on his 3.1 turbo with massive 400hp+ capabilities.

[SappySE107]

All of us seem to think the aluminum heads are the way to go? We dont have many iron head owners here so that probably doesn't help with spreading information on them.

Got a flowsheet on a set of ported iron heads? Im not interested in .500 lift values really as its hardly the most important value for flow.

[rx191]

i will see if i can find the flow sheet for the heads the 235 CFM was at .400 valve lift because the max was .450 for the race class the motor was built for i'm sure the flow more at .500 but the valve isn't open there much at all. i'm more interested at the .300- .400 flow number s i feel they give you a good idea of how an engine will make it's power. and i do own an iron head 3.1 as well as an 3100. i'm just getting pissed that everyone on here wants me to switch my 3.1 iron to alummiun so i'm shooting for 240HP out of it with a carb . i love injection but it just doesn't work well on the iron motors a carb is the only way to go. when the motor is done i will put the dyno sheets on here till then i will try and find the flow sheets for the ehads we did i know i have a copy somewhere

[SappySE107]

I focus more on the .050-.250 numbers personally. You are shooting for 240 crank or wheels NA with a carb and iron heads?

[Doubt_Incarnate]

dont ask where i got this, it was years ago and all i can remeber of the site is something about a 2.8 to 3.4 swap in a 84-ish camaro and the makins of a turbo project.

stock iron head flow:

intake exhaust
.1" 50cfm 50
.2 90 79
.3 125 98
.4 157 103
.45 169 107
.5 177 110
.55 177 110

thats what i have plugged into the dd2k program, it seems to work out as far stock hp claims go.

[SappySE107]

Im curious how your flowbench is setup with 235 cfm at .400. Are you using a tube to replicate the cylinder? Thats just a lot of flow at .400 for iron heads, let alone aluminum heads.

[geoffinbc]

The reason behind the mentality is very sound though. If you poured all that work into a Gen III head then you would still be ahead of the game versus an iron head. Iron heads are good though. I bet under extreme situations they will hold up better. Like high boost and heat.

If you can find any 1.7 rockers for the iron head then let us know becaue it will fit the aluminum head. The best I have found to date are the 1.65 ratio rockers from Harland Sharp. Iron heads come with guideplates and hardened pushrods. They are both just as easy to find for the aluminum heads so I don't know why you brought that point up.

[sharkey]

thing is with a gen 2/3 head, there realisticly isnt as much that can be opened up in the heads. if you put a ton of time and research and flowbench time coaxing every last cfm out, mabey they will outflow an ironhead. an ironhead can be ported more, and in the end result could flow the same amount.

as far as intakes, thats were the ironheads get shafted. its not to bad if you have a carb, there are options for that. however, for fuel injection, there is only so much you can open up. the nicest intake has to be the truleo for the fiero, buts its to tall to clear the hood on the fwd cars. one of the projects im tossing around is building a custom intake that will fit under my hood. this is a big task as the fiero intake already almost hits my hood. im thinking about a twin plenum/tb setup using 2.0l turbo throttle bodies (42mm each) and having the plenums over the valve covers. its a pile of work and design, but i think it could be worth a lot of power, especialy were my power falls off around 5500.

[rx191]

we are getting those flow number s on an acutall flow bench i can't remmber the name of it right now. the iron heads really have flow restriction in the bowls and around the guide, with just some very basic porting you can help these areas alot. i'm shooting for 240 hp at the crank with all acc installed and functioning, like alt. and waterpump the 1.7 ratio rockers i have found would require guide plates but i don't know if they are narrow enough to work on the gen2-3 motors i will get you guys all the specs on them that i can find and some part numbers, tommor sometime

[Doubt_Incarnate]

i'd like to see a diffent FI intake for the iron heads. i was looking at the way ford and other companys make their intakes.one i was tossin around was a simple tube on very short runners mounted to the original lower intake, that would provide better high rpm power, but not my thing. the other thought was similar to the ford 5.0 intake wich is like the tdc intake. large plenum with all 6 runners sweeping off of the one side and then down into the lower intake. unfortuanatly this requires alternate fuel rails.

i can see where the upper intake/plenum, and the middle set of runners are restricting. but i think the stock FI bottom is good to go, we just to need to work from that.

[Naft]

http://www.supersixmotorsports.com/pdf/SSM2006PortedCylinderHeads.pdf

last one at the bottom:
240/202 CFM assembled with .54 lift springs for the low low price of $1350 plus shipping, plus shipping for your heads to them. but thats a hell of a port job, over at thirdgen.org all the headflow numbers weve gotten for stock irons have been in the mid 100's, 150-ish or so.

[SappySE107]

Wish they had a complete flowsheet. No lift given and no clue what it flows at low lift. Do they use a tube to replicate the cylinder? This is why I like flowing everything myself...I know its consistant testing at least.

[Doubt_Incarnate]

they stole my idea of using late model 3400 valves. at least i know it can be done now.

[Naft]

Wish they had a complete flowsheet. No lift given and no clue what it flows at low lift. Do they use a tube to replicate the cylinder? This is why I like flowing everything myself...I know its consistant testing at least.

agreed, as sooon as i get more serious into getting some heads im gonna call them and demand some details, cause $1000-$1400 is a crap load of money to blow based on two numbers. the thing is at this point they are barely an option because of the price, so i havent found out all about them yet.