iron heads
09-27-2005 | 04:20 PM
#1
Thread Starter
Teching In
Joined: Sep 2005
Posts: 2
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iron heads today , i picked up some misc lt1 parts for cheap and among the parts is a set of 12554290 iron heads.I was just woundering some of the pros and cons of these heads? and if anyone ever uses them.
jim
jim
09-27-2005 | 08:53 PM
#4
How little do you guys know and why do you insist on sharing?
Iron soaks up heat SLOWER, aluminum is actually a worse material from this standpoint because it takes heat from the chamber and puts it into the cooling system where it is waste instead of being used to expand the combustion gasses and drive the piston down. Not saying irons are the best just that neither of you has any good info presented on actual pros or cons.
They flow MORE than all but the 96-7 aluminums and as well as those, meaning Bandit that those heads that are so bad flow more than what is on your car. On the downside they weight 45lbs or so more FOR THE PAIR and have pressed in rocker studs as opposed to the aluminums screwin, the irons also need a bit of pushrod slot clearancing for use with high lifts.
On the old compression argument aluminum does allow more compression BUT due to the fact it saps heat out of the chamber it also REQUIRES more compression just to equal irons power. Now it may allow a full point more but then only need half that to make up for the thermal differences I have seen no real data on that part so the compression thing may or may not be a net gain in the end.
The way iron transfers heat more slowly also means it would transfer less heat to the intake charge as it passes through the ports and that less exhaust heat would be expelled rather than soaked up in the ports.
I am in no way saying everyone should switch to iron heads just that they do have some advantages as do aluminums and each has it's uses as well as MOST arguments made against them are pure ignorance. Machining the irons for screwin studs can be a little expensive and is one reason many switch to PORTED aluminums when swapping cams. Stock for stock from either to either would be a mistake and I know someone who made the swap to stock 96 Vette heads ASSuming they would be a performance gain. Only after he got no gain did he research it and find his mistake.
Also browse a b-body board once and tell me how many head gasket failures you see as compared to with the f-bodies, VERY low numbers I can only think of one or two in the nearly 5 years I have been active on the two main b-body boards, be it the differnt thinner gasket the better expansion match with the iron block iron head combo, or just the iron retains clamp load better either way one less problem we have to deal with that you guys do.
Iron soaks up heat SLOWER, aluminum is actually a worse material from this standpoint because it takes heat from the chamber and puts it into the cooling system where it is waste instead of being used to expand the combustion gasses and drive the piston down. Not saying irons are the best just that neither of you has any good info presented on actual pros or cons.
They flow MORE than all but the 96-7 aluminums and as well as those, meaning Bandit that those heads that are so bad flow more than what is on your car. On the downside they weight 45lbs or so more FOR THE PAIR and have pressed in rocker studs as opposed to the aluminums screwin, the irons also need a bit of pushrod slot clearancing for use with high lifts.
On the old compression argument aluminum does allow more compression BUT due to the fact it saps heat out of the chamber it also REQUIRES more compression just to equal irons power. Now it may allow a full point more but then only need half that to make up for the thermal differences I have seen no real data on that part so the compression thing may or may not be a net gain in the end.
The way iron transfers heat more slowly also means it would transfer less heat to the intake charge as it passes through the ports and that less exhaust heat would be expelled rather than soaked up in the ports.
I am in no way saying everyone should switch to iron heads just that they do have some advantages as do aluminums and each has it's uses as well as MOST arguments made against them are pure ignorance. Machining the irons for screwin studs can be a little expensive and is one reason many switch to PORTED aluminums when swapping cams. Stock for stock from either to either would be a mistake and I know someone who made the swap to stock 96 Vette heads ASSuming they would be a performance gain. Only after he got no gain did he research it and find his mistake.
Also browse a b-body board once and tell me how many head gasket failures you see as compared to with the f-bodies, VERY low numbers I can only think of one or two in the nearly 5 years I have been active on the two main b-body boards, be it the differnt thinner gasket the better expansion match with the iron block iron head combo, or just the iron retains clamp load better either way one less problem we have to deal with that you guys do.
