Good Head
 

Now that I have your attention :D :D here's my question.

I got a dynamite deal on two pair of Canfield large oval port raised runner aluminum heads(brand new).Somebody out there makes and aluminum "marine" head with some type of coating to help resist corrosion.
Question is , who or what is the coating and can I do it or get it done somewhere???
I'm rarely in salt and when I am I always floss...I mean flush :rolleyes: .My aluminum intakes have been powdercoated...including the water passages but I really don't think that would be practical because of heat tranfer or even possible due to the intricity of the waterjacket.
Having seen first hand what salt can do to aluminum , I really don't want to leave them naked :o

Re: Good Head
 

Canfield and Edelbrock have them hard anodized. You are looking around $300 a set.

Chris

Re: Good Head
 

A marine mechanic I know around here said he had aluminum heads on his boat, ran in salt for either 8 or 9 years, then sold them. I reckon they will last. :)

Re: Good Head
 

Didn't MerCruiser make a block that was Aluminum in the mid 80s? I think it was called the 470 and it was a 180-HP 3.7 liter 4-cyl. Now if memory serves me correctly (and it doesn't always) I believe they had closed cooling systems but some may not have. I wonder if anything special was done to this block to resist corrosion? I think I recall that on this engine the block was aluminum and the head was iron.

Roby

Re: Good Head
 

Those MerCrusier 470's and 490's were all supplied with a closed cooling system. No seawater to the Au. And most all manufacturers of marine aluminum heads offer them with a hard anodize option for saltwater. Don't know about getting them anodized after the fact though. Let us know if you find out if someone does it. Thanks! --- jp

Re: Good Head
 

Yes , I'll keep up my search locally first , then go national if necessary :rolleyes:
I would feel better with some type of protection although in my situation it probably isn't imperative.

Re: Good Head
 

I have no experience with aluminum heads on a marine engine, however I would like to throw one other thought/concern out there...
Aluminum and cast iron expand and contract at vary different rates. Raw water cooled engines temperatures vary tremendously while running. I would think that the extra $600-$800 for a closed cooling system would be well worth it. Maintaining a more constant temperature could save head gaskets.

Re: Good Head
 

That's a good thought Pat, but the alum. head sits on the iron block square. (90 deg. cuts on both) The major problem with the different expansion characteristics of the dissimilar materials is where the intake manifold joins the head. If you have a cast iron intake, and a cast iron head, and cast iron block, all is fine. But most performance intake manifolds are aluminun and the surfaces join the head at an angle that requires some sliding at the joint with expansion. (NOT 90 deg.) So things will all stay sealed better if the head is the same material (and expansion rate) as the intake manifold. --- jp

Re: Good Head
 

jpclear,
Though a connection of mine I found I can get my heads done for $100 each.
I guess it's worth if for the peice of mind :rolleyes: :cool:

Re: Good Head
 

MOP; thanks for that reply. If I have to tear-down or plan a saltwater trip I'll be in touch for the contact! I could have gotten my Canfield's done for $300 at time of purchase but they recommended that I save the money unless I was running salt, cause should the head need repair, anodize makes them a bugger to weld properly --- jp

Re: Good Head
 

JP,
From what I was told the hard anodizing must take place BEFORE te hardened valve seats are put in. The process cannot be done in the presence of dissimilar metals :(

Re: Good Head
 

JP,
From what I was told the hard anodizing must take place BEFORE the hardened valve seats are put in. The process cannot be done in the presence of dissimilar metals :(

Re: Good Head
 

Well they made it a week sooner than expected :)

Re: Good Head
 

The hard anodizing left them almost black. When I first saw one I thought it was steel not aluminum :eek:

Re: Good Head
 

Back end of the old 'Bird should sit and inch higher now :D

Re: Good Head
 

Yep ... after swapping the iron for aluminum last winter (heads , intakes , exhaust ) the boat is 300 lbs lighter. The water line is about 2 inches less @ the swim platform now.

Bob

Re: Good Head
 

Already have he intakes and exhaust , that's why I figured 1" :)

Re: Good Head
 

Mo, what heads gaskets are you using. . .what Generation blocks?

Chris

Re: Good Head
 

Merlin generation blocks :D. I haven't given head gaskets much thought yet. I am going to head studs rather than bolts. Also want to match the size of the ports to the flow requirements of the blocks. My current Merlin heads are too big and as a result my port velocity is down. :(

Re: Good Head
 

470 Merc was based on parts from the 460 Ford. It was basically "half" of a 460 V8. Custom crank, but used 460 head, rods, bearings, pistons.

I saw one in an old Starcraft that had raw cooling. Not closed.

Anodizing will give you a barrier between the salt and the metal, but you must still treat it as a delicate situation and flush religiously. And any scrape or scratch in the coating will leave that spot bare and vulnerable.

Re: Good Head
 

I had one of these in my 1988 Sunrunner CV 195.. great little motor, beat the hell out of it running 4,600 rpms for 9 years.

Re: Good Head
 

Those had aluminum heads :confused:. The ones I've seen , I'll swear , had steel Ford heads.
I'm usually in fresh water anyway , and when I do the salty thing I always flush. It I had more room in the engine bay when I changed mine , I would have went the FWC route :(

Chris, I was just talking to my engine builder and he said use multi layered steel gaskets. I forgot the brand already :rolleyes:

Re: Good Head
 

I used John's heads on 540's and 572 NA engines and they worked real well. We had a ton of gasket problems on the 540's and I finally found Mercury Racings gasket guy, after that problem was fixed. Cometic has come on strong a make nice composite steel layered stuff. Since you have merlin's, you should be fine.

Chris

Re: Good Head
 

The 470 was a Ford Backhoe engine used in Ag and Industrial stuff. Used for years until diesel stuff took over.

Chris

Re: Good Head
 

Cometic :o ! That was the brand :)

Re: Good Head
 

Merc used Fords heads on the 470. They were steel heads on an aluminum block that Merc made. I saw a few that changed over to raw water cooling when the heat exchanger went bad. Look at outboards, they're all aluminum and none are fresh water cooled. They last many years and the aluminum is pretty thin walled in a lot of areas.

Re: Good Head
 

Latest update. Got my heads back from the CnC shop last Wednesday after sitting there for 6 weeks :mad: . Well , the valve job is scheduled for tomorrow :rolleyes: . and the shortblock is already bolted on the dyno for next week. These were flow bench designed and tested for a 540ci at a max of 5200 and should bring my hp band down to where I want it. The Merlin heads were 638hp@5800. Details to follow :cool: