They have the CH454A head which is the heads i purchased. Those are the raised exhaust port, copies of the old RHS / Protoplines. They also have a CH502 head, which is meant to be a replacement for the stock GM /Merc head. That head is almost 50 bucks cheaper at around 385 dollars per casting bare.

One thing I noticed, was I had to run a richer AFR with a iron headed super charged engine. That is comparing same builds, whereas the only difference was iron eagles vs. brodix, everything else being identical.

Lets say your water jacket is at 200 degrees regardless of material type. The iron head will make more power because it will keep more heat in the chamber than the aluminum.

Now lets say you increase compression/boost etc. The aluminum head is still okay at 200, but the iron head needs to come down to 140 to avoid issues. Now you increase more, and the aluminum head needs to come down to 140 and the iron head either needs more octane or to be richened up to avoid issues. I think that is where aluminum starts to have an advantage and why cooling temps come down. Yes you start increasing heat transfer but you have to to allow the other big performance changes to occur safely.

They were also both low-boost engines with low compression ratios, that was sorta my point. It was old technology.

If I never moved to the northern Chesapeake and stayed up in NJ in salt water, I probably would have never switched over to aluminum.

But in the same regard, I would have never attempted to make the 965hp I have now with Iron heads.

Read info years ago were it would be better to have an aluminum block with iron heads by some experts.

When you swap the heads,are you doing other engine work as well. I'm really curious about the numbers if you are basically just changing heads, and retuning .From what I read of your stuff I'm assuming it will be run on a dyno. It would be cool if you could check at least on motor as it is now ,change heads and re dyno.....All in similar weather ,same dyno

How did you come to that conclusion? High EGT`s till you gave it more fuel? Just curious.

btw, I wish i could run higher engine temps temps... running no water temps is not by choice for me.



Why?

Wonder whats the most power one made reliably in a marine engine, with iron heads. I know a friend of a friend just bought a boat with some big Sterling blower motors. They have iron heads. Surely guys like Cheif, Zul, Sterling, and others must have built some big power saltwater ran engines with iron heads over the years.

First off THANK YOU to Joe Mild Thunder for sharing GREAT info like always, looking forward to hearing your positive results. There are a TON of members on here that could really appreaciate and benefit from the cost savings of these heads.

My factory sealed 800ish HP procharged 7psi iron head 500efi's are still going strong for the new owner after 300hrs pushing the Baja hard to 100mph.

The average powerboater with lower to mid hp levels would be fine with iron heads. I would rather see that then some of the other corners people cut, but hey they got fancy aluminum heads!

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