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View Full Version : Alum. heads or steel heads?



racingrascal
07-01-2001, 01:39 PM
I am thinking of building a 540 merlin for my new boat want to know the ins and out of alum vs steel heads. The cost diff. is only a couple of thousand.Any help would be great.

Craig
07-03-2001, 04:22 PM
Most of the bigger aftermarket companies, Dart, Merlin, etc. make good heads in both material. I think the aluminum will save you a good deal of weight and are a little less sensitive to detonation due to the fact that they don't retain as much heat in the head. They are also easier to repair in case of the dreaded valve failure. And lastly, they look so cool when you get the outside of them polished prior to installation!
Iron will save you money.
My 2 cents, and it might not even be worth that much!
Craig

racingrascal
07-03-2001, 04:32 PM
Thanks Craig every little bit helps!!

boatnam2
07-03-2001, 05:42 PM
hey racing rascal where abouts do you live in lakewood.i lived at bellflower and south behind in and out for 13 years.got a divorce this year she got the house and i got the payment.

racingrascal
07-03-2001, 05:47 PM
Boatnam, Del Amo and Woodruff. My girlfriend lived behind In & Out on Adenmoore Two years ago.

skijake
07-09-2001, 09:18 AM
Alum vs. Steel always a hard question
Alum does look better and does save weight, but they do cost more.
Steel can make more power because they retain the heat and what works best depends on your set-up and how you plan to run.
You have to take in to account your compression ratio, the fuel you will be using, your induction system, and your water cooling system.
Some boaters will want some more power so they put a bigger cam and headers on their natually asperated engine, change the cooling water to once through, then put on an expensive set of alum. heads and expect massive amount of horsepower. They may make move power over all but becasue the engine is running cool and the alum heads are doing their job and removing extra heat they will be losing power.
Your combustion chamber needs heat to perform properly and to make max HP.
If you are upping your compression ratio, or running a blower and close to detonation then you may want to consider alum. heads.
Good Luck.
Just my two cents

77charger
07-09-2001, 04:44 PM
aluninum is better for the weight savings but are easier to warp if they get hot also handle detonation easier by better heat tranfer but in my opinion steel is harder and will probably last longer and can take more hp.

jaqquuuz
07-23-2001, 07:50 PM
oops
[This message has been edited by jaqquuuz (edited July 23, 2001).]

racingrascal
08-03-2001, 03:30 PM
I decided to go with the alum. heads. A lot of people think it will make more power with the alum. becuase you can run the compresion higher on pump gas with alum. I am also putting a tunnell ram on the motor now. Any thoughts on the tunnel ram? Thanks with all of the help guys!!
Andy

smash
08-05-2001, 11:46 AM
alum heads below 6000 rpm steel above. tunnel rams are for show victor jnr with 2" spacer will work better. spend a the money on porting and flowing the top end works on the river

555cid
08-09-2001, 08:49 PM
My old motor was a 540 rect port head ported iron with bigger vaules soild cam 9.1 com the motor 555 alum dart heads 10.1 hyd cam the new motor will out run the old motor bad. I can't give the speed differnce because I think I have a bad lifter but even with the motor making bad noises at high rpms it clearly pulls much harder past 3500rpms and has allready 5mph faster I think its going to do eight. Same carb and intake and manifolds may just be the compression the motor man said the alum heads and he has the dyno.

racingrascal
08-11-2001, 01:27 PM
555, you think the alum. made the difference? Anybody else have thoughts on the tunnel ram? Thanks again for the help guys!
Andy