iron heads ... and cooling

[zooguy]

okay so i have read a lot of stuff about the AL vs. FE heads and i think for what i want to do the iron heads will be just fine ... the only down sides i see are the weight ... only 50ish lbs and the heat soak ... so the heat soak is what i really want to discuss here.

some people say that he heads hold heat enough to the point that the heads can cause detonation.

does anyone know what temp that happen at? also if i run a 160 t-stat or even no t-stat so that the coolant is always running in the heads with and i run BOTH fans on high at all times will that keep them cool enough to prevent this? also would running a ELP help keep it cooler? i know they flow more at low rpms but not at much at high rpms. i wont be running A/C on the car so i could even run a custom thicker radiator to fill the extra room would have ... would that be worth the $$$ to help with cooling?

[dawdaw]

In all honesty unless your trying to save money because you already have some cast heads I would just go aluminum..

Heat soak I wouldn't worry. Run a 160 to 180 thermostat with good 93 pump gas and a cooling system that is in check and up to par and it'll be fine.

Fwiw last year we rebuilt my neighbors 461" olds with factory casting c heads. The ONLY THING we changed was going to a low tension oil control ring and the car ran 15* cooler across the board. I can't rember what we ran for the top 2 I think they were gap less total seals

[shownomercy]

For the price of stock aluminum heads, why bother with iron?

[firebird_1995]

I spoke with Lloyd once about having some iron heads done for an l99. He told me the decks on the iron heads was thinner and more prone to cracking. Not sure if it is the same on the iron lt1 heads but its worth looking in to.

[zooguy]

reason i am asking about iron is i got a b-body LT1 for free and it just needs to cleaned up ... i like being the challenge ... the LT1 is already the underdog to LS platform and the iron heads are almost a small step down from the aluminum heads.

it had a little rust in the cylinders so its going to be a 355 but the stock cast iron heads will get cleaned up screw in posts in place of the press in ones, 1.6 rockers and maybe a decking just to know the surface is 100% true and give me a tiny compression boost. im a nitrous guy so there wont be any port and polish on these heads .... but later when i have more $$$ to get some heads done over by LE then i will go to the ALUMINUM heads.


being that nitrous in the plans that is why i had the fear of detonation. nitrous dont like that.

[dawdaw]

Detonation is the result of over timed and or lean. You can combat that by running a good quality fuel, correct ignition timing, a good cooling system.


If your up for a challenge do it. Start of small spraying and learn how to read plugs. Get a stand alone with some VP import you won't detonate that :)

[Paulster2]

I would double check to ensure it's not an L99 before you go to all the trouble. In case you are unaware, check the side of the block for casting marks (right by the bosses for the motor mounts). If you see "327" on the side, it's an LT1. 588 and it's an L99. You will never get the FE heads to flow very well ... I'd poop-can them and be done with it. Like said, a set of stock AL heads will do a great job at a cheap price.