aluminum vs iron heads

climate standpoint.
Ok the dart iron eagles and dart pro ones are alike heads why would you have to spend a lot more money on them to install bigger valves, hardened seats, porting and there is a $300+ difference.
I have seen a lot of people that think they have a powerful engine just because they have aluminum heads.  
Professional hi-performance engine builder

Horsepower sells Engines and torque wins races.

we all know aluminum heads alone dont make a powerful engine most stock cars now have them.they help against detonation and tend to flow better out of the box.i used to not want them because of overheating and warping but its never been a problem and i run a 450 hp 383 with a stock water pump and radiator with dual electric fans.so i dont see alot of drawbacks anymore  

excuse my ignorance, but how does climate affect aluminum heads?...tropical as apposed to somewhere that has four seasons


my comments about money spent machining iron heads in relation to the cost of aluminum heads was written thinking that if you were to take an older set of iron heads and try to update them that the same money would buy (unless you are a machinist) a set of aluminum heads that would already be where you were trying to take the iron heads, and have a weight savings...however, if you were to going to buy new heads anyway, it would be a matter of material preference

personally, i've had good luck with aluminum and i like the fact the they weigh much less than iron...so i'd go with aluminum again  
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the red-headed step-child of the mailing list

fuzzy dice, air shocks & N50's rule

Well when you live were in the summer the temp reaches between 90-100 degrees you would be more likely to overheat the engine and aluminum heads would not last long.
I have seen many aluminum heads in the machine shop I go to that are warped some so bad that they could not be fixed.  
Professional hi-performance engine builder

Horsepower sells Engines and torque wins races.

i do live an a place like that (except this year) and i do have an aluminum headed stroker...it hasn't over-heated...but that was a conscious effort from the beginning...four core radiator that fits my chassis/model...dual elctric fans that are thermostatically controled...coolant temp gauge that is monitored just like the oil pressure gauge is  
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the red-headed step-child of the mailing list

fuzzy dice, air shocks & N50's rule

the surface finish on heads really effects the ability to resist head gaskets from leaking...   the surface finish on the block also...    

how you torque them down also....   snugging the  head bolts... then setting the torque wrench at half the finish torque.. and going around .. increase it 10 pounds.. and go around again...  keep going so the last pull is at least 10 pounds..  if the bolts are pulling properly..  the torque wrench will move even amounts for each bolt.. with slight reductions for shorter bolts..

i also have gotten tired of doing heads twice..   so i learned back in the mid 90's about Hylomar...  professional engine builders buy it by the quart and gallon..  harbor freight sells it in a 3 buck tube..  worth its weight in gold..

overheat the engine and  blow a head gasket.. nope this stuff does not harden..  it is good for 600F..   it does not wash off with gasoline.. .   have to take one back apart do to a tiny leak... nope...

i even trained some techs to go around the intake bolts 3 times  after they did a brought the torque up in steps..  

i read about that some dozen or so years ago and generally split the total torque into thirds and round to nice torque wrench friendly numbers (end w/0 or 5)...

and start with 20-25 as a first torque starting point...
and read and follow bolt manufacturers (ARP) recommendations for lube/torque specs

the torque wrench reads in single ftlb increases, i just like easy mathematical numbers

just a li'l fyi as a reference for my pov...this particular motor was put together in august-99 run hard (go or blow) until june-00, trans-planted, run occasionally for 6 months then parked until march-09,  with some care taken prior to turning the motor over, it fired right up and the only problems are the oilpan gasket leaks (funky after-market aluminum pan the needs to be replaced anyway)...maybe i'm lucky...maybe i got tired of doing it twice and took EXTRA care with this one...just my experiences talking  
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the red-headed step-child of the mailing list

fuzzy dice, air shocks & N50's rule

ok lets take a couple steps back instead of getting into a fist fight again, what kinda engine are we working with,  what are you looking to get out of it.  

not trying to argue or fight...just trying clarify my point of view and why it is what it is  
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the red-headed step-child of the mailing list

fuzzy dice, air shocks & N50's rule

Ya there is no fighting just some people learn the hard way and others do not.  
Professional hi-performance engine builder

Horsepower sells Engines and torque wins races.

99% of people that run aluminum heads have no problem i dont know what all this overheating talk is about and i dont know how thats learning the hard way.i have aluminum and on the hottest summer day this year(85-90)i ran the *** out of it and never got over 185.learning the hard way is having an old ported set of camelbacks and and a guy with a set of afr eliminators wiping his ass with you  

Maybe that has happened to you but that has never happened to me.
Besides no one said to go with a set of old double hump heads comparing double humps to afr's is like comparing a cam shaft to a tire no comparison.  
Professional hi-performance engine builder

Horsepower sells Engines and torque wins races.

i dont know about cam to tire maybe stock cam to a comp or lunati,lol.but im just saying lets not scare everybody away from aluminum they have more than proven themselves.all gmpp top crate motors have them and a 30000 mile warranty.all the new motors have them if not an aluminum block too.if your always overheating your problem lies elsewhere and it dont matter what heads you have the irons could crack and the gaskets are definetly gone.your telling me you have never had or seen a good,reliable aluminum headed motor that didnt overheat and warp the heads  

if i can throw an observation or two in...pontiacman, i'm not trying to put words in your mouth, just read your abilities and philosophy...

i think that pontiacman, being an automtive machinist (that's what engine builder means where i'm from), has the knowledge and skills to port the piss out of a set of factory iron heads and get excellent results...uses this ability to run iron heads and save the cost of a set of aluminum heads and use that money elsewhere...reducing the overall price of the buildup...and he can abuse the iron heads more than what a comperable set of aluminums would take...

i on the other hand have to read every little tidbit of tech to get all the juicy information that is mostly known only to guys like pontiacman.  i can only buy the best set of heads that i can afford (along with complementing components) and assemble the best motor i can afford.  all the reading and understanding of tech will never get me into someones machine shop to do it myself, so i have to otherwise educate myself on what to look for and why things work (read david vizard's head porting book if you aren't fully aware of how stock class cars make so much power)...and find a machinist i can trust

in the long run, i have to be carefull to not beat on my stuff too hard while guys like pontiacman know just how hard they can beat on their stuff before it blows...he doesn't worry when the temp gauge reads 230...i start to panic at 215

and i too do not understand all the overheating going on recently  
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the red-headed step-child of the mailing list

fuzzy dice, air shocks & N50's rule

you said it scott