Starting from scratch on a blown 454 motor for my floating money pit. Have got all winter and want to do it right, but keep getting different stories on aluminum vs. cast iron heads. Obviously, aluminum heads are going to flat-out perform better, but have heard they may not be as durable over time.
For a guy on a budget who doesn't want to pull the motor annually, what should I be looking at? Durability over performance? Or is there that big of a difference? Have at it... Thanks.
The main difference between aluminum and iron is that the iron heads retain heat(makes more power), the aluminum's dissipate heat, not that they perform better in an equivalent head. The biggest factor is if you run alky, it takes a lot longer to get heat build up with an aluminum head than an iron head,a lot longer than with gas!. Personally, unless I was on weight diet I would run iron heads, besides the corrosion factor is a lot less with iron heads!...Just my worthless .02......
GofastRacer:
The main difference between aluminum and iron is that the iron heads retain heat(makes more power), the aluminum's dissipate heat, not that they perform better in an equivalent head. The biggest factor is if you run alky, it takes a lot longer to get heat build up with an aluminum head than an iron head,a lot longer than with gas!. Personally, unless I was on weight diet I would run iron heads, besides the corrosion factor is a lot less with iron heads!...Just my worthless .02......
That is "ONLY" if it gets out of control. W/ fuel that burns fast and timing too early, it will happen.
argue
on a boat your temp is alot lower than a car.So yes detonation is less likely.My choice would be cast.Weight an issue and i had lots of extra money than alm would be the choice.
i would definatly run cast on a blown motor. will have a much longer life expectancy. and yes heat does = more power to a certain degree. you dont want the motor running to cold or you run the risk of premature wear in the front 2 cylinders because of lack of expansion. if it were me i would run forged pistons, cast large chamber square heads with the blower. if you take the time and put it together right it should last a long time. good luck!!. p.s. if you come across more then one set of large chamber square heads let me know, im looking for a set myself.
when you say large chamber "square" heads, what exactly do you mean? are they differant from the large reqtangular port heads? what vehicles came with the square port heads?
Well there were a new set of rectangular ports on e-bay..500.00 bare if you want to start from scratch and go that route. I personally use Brodix aluminums. All the previous points are valid but when and if you nuke one, you can weld aluminum easily. I was told by Brodix that they could save just about anything that was short of being blown in half. Bottom line..Less weight = free MPH. Repairability...A big plus. Horsepower?? No question the aluminum heads win this one too...You make your own call But your budget will have an opinion, Brodix are around 2 grand for a set ready to run.
Get a set of 990 cast heads and some forged JE pistons and I'm sure that will keep your wallet on the mild side.
O.B eddie:
GofastRacer:
The main difference between aluminum and iron is that the iron heads retain heat(makes more power), the aluminum's dissipate heat, not that they perform better in an equivalent head. The biggest factor is if you run alky, it takes a lot longer to get heat build up with an aluminum head than an iron head,a lot longer than with gas!. Personally, unless I was on weight diet I would run iron heads, besides the corrosion factor is a lot less with iron heads!...Just my worthless .02......
As we always say "weight is horsepower" as well.
Weight is one reason to select aluminum heads. Ease of not only repair but modifying them as well is much easier. I would prefer to port a set of aluminum heads any day over iron. You can taste iron for days after porting a set of them.
I run aluminum heads not only on my race motors but my boat and even my 1 ton Dually.
Aluminum heads will corrode faster but steps can be taken to prevent this as well. In auto you can use a good corrosion inhibiter, this will extend the life tenfold.
In marine use, hard anodizing and sacraficial anodes will take care of the problem. I run one of these as well on my truck engine.
Heat when directed properly can and does make more power if contained in the combustion chamber. Ceramic coatings can easily bring a set of aluminum heads up to par with iron heads in this respect.
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