Aluminum headed 470 Merc?

[barts5oh]

Hi everyone,
It's been quite a while since I posted on this forum. Has anybody heard of anyone putting an aftermarket aluminum head on a 470? Now I know most of you may say (why bother?), but the motor has nice torque for an engine it's size. Since the engine uses a 460 head, performance aluminum versions are available in automotive speed shops. I would like to hear all arguments for and against.

Bart

 

[Uraijit]

Re: Aluminum headed 470 Merc?

You planning on using it in saltwater? Two disimilar metals in salt water=corrosion!

What is it that you're hoping to achieve by installing an aluminum head? If you can say what you're hoping to get out of it, you can probably get better advice regarding how well it'll suit ya.

 

[TilliamWe]

Re: Aluminum headed 470 Merc?

Ok, Uraijit has forgotten that your block is aluminum already, so the aluminum head would "solve" your disimilar metals problem.

What you propose is very interesting indeed. I haven't heard of anyone doing it. And I'll guess the reason why is that the weak points of that engine are not the head. It's the charging system, the camshaft seal, the high price of exhaust manifold/risers. I also don't know what if anything Mercruiser changed on the head to use it. Or what the aftermarket makers of the aluminum head changed. Would all the accessory bolt holes be exactly the same?

So in conclusion, I'll say the two biggest "for its" would be the weight savings, and better flow.

The "against its" would be the very high cost, the motor might not perform any better, other things on the motor could/will fail and then you'll be left with one very expensive head with nothing to do with!

 

[CharlieB]

Re: Aluminum headed 470 Merc?

The flow advantages of an aftermarket head tho measurable and effective in increasing HP, are largely wasted at the RPM range that the marine engine generally operates.

The improvement in heat dissipation allows automotive applications to raise compression ratio about a whole point, requiring a complete tear down/rebuild with new pistons. An option, but not really cost effective for your application.

If this was a current production engine, it would prove an interesting test project.

Currently, the number of 470's in operation is dwindling, less each year.

Maintain what you have, unless you're like me and simply MUST tweak it until you break it, just so I can build it better, stronger, faster...........

 

[HT32BSX115]

Re: Aluminum headed 470 Merc?

Ok, Uraijit has forgotten that your block is aluminum already, so the aluminum head would "solve" your disimilar metals problem.

Yeah....he also forgot that a 470 is closed cooled too....solving the saltwater problem too...


Unless you could find an "orphan" aluminum head from a 460 that cracked the other side etc....it would not be very cost effective to just go out and buy one.

Even the Chi-com heads are pretty pricey not to mention the Blue Thunder and Edelbrocks etc... A cast iron 460 head weighs a lot! If you used an aluminum manifold with an aluminum head it would probably make the engine considerably lighter.....but for the money, I'd go with a inline 6 or a V-6


Cheers,

Rick

 

[TilliamWe]

Re: Aluminum headed 470 Merc?

HT, the fact that they have closed cooling is why I put "solved" in parentheses. Mercruiser already solved the that issue when they first released the engine.
Some of those 470s have an aluminum exhaust manifold already.

barts, I suppose if you had a lot more money and time than brains, you could build the world's lightest 224 cid 4 cylinder engine! Not a project for me, but go for it, if you wanna see if it works!

 

[achris]

Re: Aluminum headed 470 Merc?

I have heard that the old 470 engines are highly sort after. in the racing fraternity... The reasons are that they are a light-weight 3.7 litre 4 cylinder. By putting those heads, I think they're called "Dove II", I have heard reports of over 250hp .....

Chris......

 

[DJ]

Re: Aluminum headed 470 Merc?

Just because you have AL on AL does NOT mean that those two alloys are REMOTELY compitable.

Stick with closed cooling. The Ford 460 cid. head has lots of potential. Take it to post '93' spec's and you'll see a difference. All easy do's.

 

[newbster]

Re: Aluminum headed 470 Merc?

What, specifically, do you mean by post 93?

 

[CAPTKEV85]

Re: Aluminum headed 470 Merc?

I've seen a 470 mercruiser engine on ebay with 300 hp with an edlebrock head, custom cam. and pistons. He did note that he had the front of the head drilled for the antifreeze port going to the thermostat housing. the after market head does nothave that. pretty cool pushin 300hp out of a 4 cylinder boat motor

 

[HT32BSX115]

Re: Aluminum headed 470 Merc?

pretty cool pushin 300hp out of a 4 cylinder boat motor

Yeah....I wonder how long it would survive doing that......and I also wonder if they figured that using a dynamometer or are they just making the claim??

 

[CAPTKEV85]

Re: Aluminum headed 470 Merc?

I wouldnt know if the hp is true but the pics of the motor were proof.

 

[abj87]

Re: Aluminum headed 470 Merc?

barts, I suppose if you had a lot more money and time than brains

ouch!

bart the money could better spent in other areas have you seen this thread? its upgraded with the 4bbl manifold, roller rocker and i believe a ported head.
http://www.breezeworks.net/cgi-bin/MBoard/forum/display_topic_threads.asp?ForumID=1&TopicID=1336&PagePosition=2

 

[barts5oh]

Re: Aluminum headed 470 Merc?

Currently I have little time, few brains (left), little money and big dreams. A relative (sort of) offered me a Wellcraft V20 Steplift for free, the boat's in good shape (supposedly) but the motor is locked up (supposedly). The engine is an inline, and I'm assuming a 165 Mercruiser, but apparently Wellcraft didn't offer the boat with a 165 in 1980. Their brochure lists 140, then jumps to 198HP. My thoughts were to try to procure on of these little torquey morphadites, and give it some more grunt with light weight. Personally I'm not a fan of big stern weight. My Cobia 197SRV has a Merc 350 Magnum and I'm not to pleased with how it sits low in the stern. I'm not all conviced that Mercury made a mistake with the 470, after all, they built the Corvette ZR-1 motor.
This post was to throw around the idea of doing such an engine combo, but having a freshwater cooled hot 4 cyl excites me a little. I have a local engine builder that owes me some $, so getting 1 aluminum head for a Ford 385 series block should be easy. It could be easier getting a single head from a racer that just blew up his motor and destroyed 1 head.

 

[abj87]

Re: Aluminum headed 470 Merc?

sounds fun keep us posted! im sure the 470 haters would be interested too

 

[HT32BSX115]

Re: Aluminum headed 470 Merc?

ouch!

bart the money could better spent in other areas have you seen this thread? its upgraded with the 4bbl manifold, roller rocker and i believe a ported head.
http://www.breezeworks.net/cgi-bin/...ads.asp?ForumID=1&TopicID=1336&PagePosition=2

I hate to admit it (for ANYTHING 460) but the above job is absolutely beautiful! Anyone that would put that much effort into making one of those 470s look that good would have no problems with the "problems" unique to a 470.

I wish anyone luck getting a 470 running good. If i had one though, I'd part it out.

I think the aluminum head idea is a good one though. (I even considered putting aluminum heads and manifolds on my 460 when I had it.......Then I came to my senses )


Cheers,


Rick

 

[TilliamWe]

Re: Aluminum headed 470 Merc?

I'm not all conviced that Mercury made a mistake with the 470, after all, they built the Corvette ZR-1 motor.

Yeah, they built it... to/from Chevrolet's specs! They didn't design it. If they had, it would have been a disaster!

 

[DJ]

Re: Aluminum headed 470 Merc?

What, specifically, do you mean by post 93?

Vehicles/engines produced in the 1993 and up model years.

The 460 ports were "opened up" in '93' to let the engine breathe better. There were also some cam changes but that does not affect you.

 

[abj87]

Re: Aluminum headed 470 Merc?

I wish anyone luck getting a 470 running good. If i had one though, I'd part it out.

my 470 runs great! NO way i would part this motor out! it has it qurks and problems but what doesn't.

bart keep an eye on ebay i see running 470s there all the time. you might just want to drop a used one in to get ya going if the blocks trashed.