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-   -   Iron VS Aluminum heads (https://www.offshoreonly.com/forums/general-q/333907-iron-vs-aluminum-heads.html)

Mr Maine 01-21-2016 10:27 AM


Originally Posted by offshorexcursion (Post 4395858)
I find these threads amusing. Joe spends his free time HELPING others on this site. You guys think JOE doesn't already know MORE about this topic then what's been posted here before the thread started....LOL

This site is mainly used by BUDGET members. If not we all would have million dollar offshore boats.

We all can agree that with money no object aluminum would be our first choice. So would a brand new Mystic, Skater or MTI. Screw buying these used boats, they are junk!

I really don't understand how this topic is being ARGUED in such a negative way????

With no hard FACTS to prove that an engine properly designed around iron heads will be JUNK compared to its aluminum brother, just marketing brainwashing.

Come on guys (aluminum head koolaid drinker pretend Rich ballers who can afford the best of the best on every single part purchase) try to be a little more positive when participating on here. Do you want more GOOD threads to entertain us and learn or not?

I write this with a smile no hard feelings. It's all in good fun!

I thought it was an interesting discussion. I only offered some input based on thermodynamics/heat transfer as I have engineering background there (not a professional by any means).

As a side note, I'm currently building a pair of engines, and have gone with Dart 308 iron eagles. The biggest reasons I went iron are 1: Corrosion and 2: Cost.

Had I gone with aluminum, the only changes would be a smaller intake runner (not many options with iron) and probably a little more static compression.

MILD THUNDER 01-21-2016 10:34 AM

What did i miss ? Whos throwing stones or arguing ? Sure we are debating each others thoughts, but nothing wrong with that.

The main purpose of my post, was more to see if anyone has any hard data, to back up the theory of aluminum dissipating the heat, and its effect . I certainly have heard this theory for many years, its not a new one. Ive seen it mostly promoted by those selling aluminum heads.

I guess at what power level , is this even a concern ? I would love to see an Na 572 or 540 build with the Engine Quest 320 heads, or those 330 cnc oron eagles

vintage chromoly 01-21-2016 10:34 AM


Originally Posted by offshorexcursion (Post 4395858)
I find these threads amusing. Joe spends his free time HELPING others on this site. You guys think JOE doesn't already know MORE about this topic then what's been posted here before the thread started....LOL

This site is mainly used by BUDGET members. If not we all would have million dollar offshore boats.

We all can agree that with money no object aluminum would be our first choice. So would a brand new Mystic, Skater or MTI. Screw buying these used boats, they are junk!

I really don't understand how this topic is being ARGUED in such a negative way????

With no hard FACTS to prove that an engine properly designed around iron heads will be JUNK compared to its aluminum brother, just marketing brainwashing.

Come on guys (aluminum head koolaid drinker pretend Rich ballers who can afford the best of the best on every single part purchase) try to be a little more positive when participating on here. Do you want more GOOD threads to entertain us and learn or not?

I write this with a smile no hard feelings. It's all in good fun!

Funny, I didn't see any negativity worth noting.
Some differing opinions, but that's what forums are for.
Maybe try not to be so sensation to posters who offer opinions contrary to those you hold in high regard.

Panther 01-21-2016 10:36 AM


Originally Posted by Mr Maine (Post 4395878)
I thought it was an interesting discussion. I only offered some input based on thermodynamics/heat transfer as I have engineering background there (not a professional by any means).

As a side note, I'm currently building a pair of engines, and have gone with Dart 308 iron eagles. The biggest reasons I went iron are 1: Corrosion and 2: Cost.

Had I gone with aluminum, the only changes would be a smaller intake runner (not many options with iron) and probably a little more static compression.

I hear ya on corrosion and cost issues. The first thing that I ask people when they ask me what is best to use, we have a lot of discussion about maintenance and upkeep of steel vs aluminum heads. On the set of engines I'm building right now for a friend, I determined that an iron head was probably better for him for cost reasons and his regular boating habits.

I think things like Fourier's Law are very interesting topics when it comes to engines. I'm not an engineer but I do work with engineers for a living.

Panther 01-21-2016 10:38 AM


Originally Posted by MILD THUNDER (Post 4395882)
What did i miss ? Whos throwing stones or arguing ? Sure we are debating each others thoughts, but nothing wrong with that.

Some posts were modified after posting but that's ok... moving on!

vintage chromoly 01-21-2016 10:39 AM

On a side note, I just got done with a mild (450 ish hp) 446 for my Mopar. We used iron HP Mopar castings that are widely considered "old school" and outdated. With a good bit of port and bowl work, meticulous setup and a good valve job, we achieved a good result.

If I believed that the only way to go was to buy some "bolt on" aluminum heads, I'd be a grand lighter and no further ahead.

offshorexcursion 01-21-2016 10:40 AM

Honest question

What is, or is there, a realistic max power level for a properly built Marine engine with Iron heads?

Or should it be at what power level is the cost savings not worth it anymore?

LOTS of good info on this thread for and against IRON heads!

Mr Maine 01-21-2016 10:52 AM


Originally Posted by offshorexcursion (Post 4395889)
Honest question

What is, or is there, a realistic max power level for a properly built Marine engine with Iron heads?

Or should it be at what power level is the cost savings not worth it anymore?

LOTS of good info on this thread for and against IRON heads!

My first thought here (and very simple thinking) is once you reach max cubic inches, max boost for max octane all at max compression for iron heads, you could go a little further with aluminum heads on the boost/compression talking gasoline.

The other issue is most ultimate max performance heads will be aluminum with no iron counter part.

And what is the number for say a 632 inch running 112 octane? 2000 horse?

Panther 01-21-2016 11:03 AM


Originally Posted by offshorexcursion (Post 4395889)
Honest question

What is, or is there, a realistic max power level for a properly built Marine engine with Iron heads?

Or should it be at what power level is the cost savings not worth it anymore?

LOTS of good info on this thread for and against IRON heads!

In my experience with boats it was right around the 800-850hp mark. In my own engines and others that I've worked on over the years I would notice signs of heat on the deck between cylinders and on head gaskets between cylinders. Once I switched over to aluminum I saw those tell tale signs go away. I also noticed, with blower engines, valve sealing (valve sealing with the seat) to degrade faster, especially on the exhaust side with steel heads. On the flip side, I've seen aluminum head surfaces wear faster. And, just because they're aluminum doesn't mean they don't corrode. I had to have my hard anodized AFR's worked on around the water passages after 3 seasons. They never leaked but when I did my builds last year I had to have them fixed. Suffice to say, now my engines get fresh water flushed regardless of how much salt (lack there of) is in the water I boat in.

Panther 01-21-2016 11:06 AM


Originally Posted by Mr Maine (Post 4395894)
My first thought here (and very simple thinking) is once you reach max cubic inches, max boost for max octane all at max compression for iron heads, you could go a little further with aluminum heads on the boost/compression talking gasoline.

The other issue is most ultimate max performance heads will be aluminum with no iron counter part.

My thoughts exactly


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