Mercruiser 470 170hp questions

[ftltony]

Greetings!

New guy here, My name is Tony, I live in Fort Pierce, Florida. I'll update my profile in awhile but first....

I am looking at a boat that has a Mercruiser 470, 170hp engine. 3.7 litre I think,,?... Anyhow, I am interested in things I have read both here and other places about the "stator" charging system I have found the "conversion kits" for $395 and I was wondering, is there ANY other way to convert the charging system from the stator to the alternator? Is there a place to get the wiring harness and other items without buying the alternator they supply?

Can I just purchase the same brackets, hardware and wiring harness and flywheel for the crank from a junk yard off an inline Chevy 4 cylinder motor and attach them to my motor to do the same thing?

Is the stator wiring harness able to be "modified" or do I need to get a cartain wiring harness for the new alternator?

I ask this because, the alternator they supply does NOT have a "lifetime" waranty on the alternator and as far as alternators go, in both my trucks and boats, they go on me a lot! Some people have trouble with other things, (brakes, water pumps, etc) MY "trouble spot" on boats and trucks ALWAYS seems to be alternators...

In addition, This same motor seems to be implicated as a 170hp... but I have seen the same model 470 listed as a 190hp. Is this just a carburator issue? If I change to a larger jet in the carb or even a new carb, will I get a higher horsepower rating? And if so, what is the highest HP rating I can get?

Thanx for all your help.

Tony

 

[Bondo]

Re: Mercruiser 470 170hp questions

Ayuh,......

Hi Tony,..... Welcome Aboard to the forums here at iboats.com,........

I am looking at a boat that has a Mercruiser 470, 170hp engine. 3.7 litre I think,,?...

I hate to start out this way,..........
But,........
If you haven't bought this barge yet,................. Don't........

The Infamous 470s were the Great New Idea that Mercruiser had,.....

Trouble is,........ It Wasn't a Great Idea,... Not even a Good Idea,......
Matter of Fact,..... It was a Bad Idea,....... A Dismal Failure is more to the Truth......
It didn't work out for Merc.+ it was discontinued Many Years ago......
The Choices for Parts is Slim,+ getting Slimmer by the day.....
It's based on a 460 Ford head,+ Merc's own aluminum block,......
So,.......
There are No Junkyard parts that'll help with Anything........

There are Millions of used boats out there,......
Find yourself 1 with a Chevy based motor,+ either a Mercruiser or Volvo drive......
OMC has been Out of Business for Years,+ Ford hasn't been used as a power source for Along Time as well......

Btw,........
I Don't believe that Anybody will warranty an Alt. in a Boat for more than Possibly 1 Year........

 

[achris]

Re: Mercruiser 470 170hp questions

Hi Tony,

Welcome to the family. And we are a very typical family and some of us agree to disagree. This is one of those occasions. I like the 470.... unlike my learned friend above, so ignore him.

You can use any alternator you find that will fit, as long as it is a MARINE alternator. You can modify the harness easily, without having to go to a 'premade'. Just connect the output of the new alternator directly to the battery lead on the starter motor and run a wire that is hot with the key on to the D+ terminal on the back of the alternator. Remove the water cooled regulator on the port side of the engine and isolate the terminals. Remove the front pulley from the engine, take the magnets out of it and remove the stator from the engine, replace the pulley, all finished.

Now the really important things to watch on these engines.
1. The heater exchanger. They are an aluminium block and have fresh water cooling. Keep the heat exchanger clean. Remove it and have it cleaned by a radiator specialist about every 2 to 3 years. Also keep the maintenance up on the leg impeller.
2. The water pump is bolted to the end of the camshaft, between two housings on the front of the engine. At the bottom of the housings is a weep hole. This will indicate when it's time to remove them and replace the seals. Another very good reason to use coolant, not just water, in the cooling system.

Now your question about horsepower. These engines started life as 170hp, with a change of exhaust manifold they produce 185hp. Add a 4 bbl carb and they are good for 188hp.

Most of the parts you'll require in the future are common with the 4 and 6 cylinder Chev engines. Those that aren't will require a new engine anyway, so no problem there. Pistons, rods, bearings, rings, gaskets are all still available.

Hope this helps,

Chris.............

 

[JCF350]

Re: Mercruiser 470 170hp questions

This engine managed to earn the nickname "shake and bake" very quickly after it's introduction if that tells you anything.

 

[ftltony]

Re: Mercruiser 470 170hp questions

Chris,

Interesting.....!

As far as the boat having problems and the engine s*cking ALL the time, I wouldn't have it any other way! What would a day on the water be for me if I didn't have SOMETHING on the boat to worry about!

As far as the boat itself, I cannot pass on this one! Its everything I've been looking for, for a long time and the motor runs, quite well I might add, I just worry about charging the battery since I like to troll for Dolphin offshore a lot and if the startor isn't charging, that (as I can see it) could be a troublespot!!!

OK, So Chris, THAT was EXACTLY the information I was looking for! ... but ... please help me out just ONE more time... you said...:

Remove the water cooled regulator on the port side of the engine and isolate the terminals.

Please describe "isolate" for me..??!?? cut off? tape off? Connect to..???

As for the Heat Exchanger, I used to have a different model boat with a Mercruiser and I remember all the trouble with the heat exchanger and after I took it to a mechanic the first time I had "slight overheat issues", he explained to me how to "service" the heat exchanger, which I did once a year and I never had problems with it again. I also used to run coolant as well. I'm also a big "lower unit impeller changer" at least once a year. Its an easy, inexpensive job that takes less than a 6 pack to do!

And I never realized that wiring the alternator would make the stator problem go away and I cannot understand why people wouldn't all do this!

.... I also want to ask, when you mentioned removing the stator magnets and stator assembly, why IS there a pulley on the front of the motor? is there a belt running something I don't know about??? Do I need to get a pulley to run the belt for the alternator or is there a pulley on there already for some reason or another?

... so changing the EXHAUST manifold lets the engine breathe and gives it more horsepower, who'd have thunk it! I would have thought it needed more gas to get more horses. If I change the exhaust manifold, do I also need to change some exhaust bellows to acomodate the larger horsepower exhaust manifold?

.. And I swear I'll quit asking so many questions!!!

And thank you to all that have taken an interest in my problem!

 

[JCF350]

Re: Mercruiser 470 170hp questions

Chris,

Interesting.....!

As far as the boat having problems and the engine s*cking ALL the time, I wouldn't have it any other way! What would a day on the water be for me if I didn't have SOMETHING on the boat to worry about!

Masochist! I say!

Hold my beer and watch this

Only if you don't want most of it back.

Welcome to iBoats.

 

[achris]

Re: Mercruiser 470 170hp questions

Please describe "isolate" for me..??!?? cut off? tape off? Connect to..???

Isolate - 6. Electronics insulate electronic device: to prevent a circuit or device from interacting with another or with an outside stimulus.
Microsoft? Encarta? 2006. ? 1993-2005 Microsoft Corporation. All rights reserved.
Tape them up or cut them off and tape them up, or cover with heat-shrink.

.... I also want to ask, when you mentioned removing the stator magnets and stator assembly, why IS there a pulley on the front of the motor? is there a belt running something I don't know about??? Do I need to get a pulley to run the belt for the alternator or is there a pulley on there already for some reason or another?

The belt groove on the pulley is for a power steering pump, usually not fitted. It was an option, for bigger, heavier boats. Use that groove for the belt for your new alternator.

If I change the exhaust manifold, do I also need to change some exhaust bellows to accommodate the larger horsepower exhaust manifold?

No.... But you would need to replace the intake manifold for a 4 bbl carb.

Chris...........

 

[TilliamWe]

Re: Mercruiser 470 170hp questions

A guy I call "Dad" took a 3.7LX out of a boat last year. It had some head damage. Anywho, he's in Central FL, and might still have the stator alternator and some of the other accessories. He replaced that engine with a 5.7, so he didn't need any of the 3.7 stuff. If you have any interest, send me a private message, and I'll see what stuff he still has.
I really hope the boat is perfect, cause there are a lot of boats out there with smoother running, easier to maintain, and still in production engines. You're just opening a can of worms by buying a boat with a 470 in it.

 

[rodbolt]

Re: Mercruiser 470 170hp questions

the MCM470 was a good idea with a poor execution.
luckily they dropped production in about 5 years or so.
had a lot of early head gasket issues due to the 3 inch heat exchanger, had a lot of overheat issure with the cast iron mnifolt riser design. new manifold is AL with an iron riser but the riser still tended to clog.
the 4bbl version with the intake oil cooler tended to spring oil leaks.
off hand I cant think of much at all that will interchange between the MCM470 and any GM motor, pint color maybe.
when,not if, the riser to exhaust pipe hose leaks it takes the starter out with it.
but the biggest two drawbacks to the design was the cam mounted circ pump and the open deck design of the block.
no fix for it it is what it is.
did ome live a long time? yep, heck I am in caracas and saw a late 50?s Edsall the other day.
does that mean all Edsalls or Corvairs were fine machines ?
the early cast iron manifolds tended to crack internally at the #3 cylinder and allow coolant into the manifold.
as far as the Altenator as long as the original system is working it worked fine.
occasionally look at the rotor mgnents to see if any are loose.
for a conversion there are NO production merc brackets tht fit that engine to convert it.
if you mke your own mounting brackets all you have to do to wire it in is to follow the altenator manufacture?s wiring.
some are one wire,some two and some 3 with the occasional 4 wire setup.
depends on who made it and its output.
easiest way is to buy the kit and follow the intructions.
myself I quit working on the 3.7L motors a few years back.
it cost to much.
last ex mnifold kit I bought was about 600 dollars as the AL manifold takes a different riser than the original cast iron manifold did.
like chris said, most the early design flaws cn be overcome,it can be expensive but done, the open deck and cam driven water pump flaws your stuck with.
try to find the cam cover when the impeller wears the cover.
if you do buy this make ure you buy the correct merc manual,not aftermarket, to properly service the beast.

 

[Don S]

Re: Mercruiser 470 170hp questions

heck I am in caracas and saw a

rodbolt = rodbolt1.0 ? Same person? Is that you Tom

luckily they dropped production in about 5 years or so.

Actually, from 76 to 89. 13 years . Mercruiser is a slow learner

 

[Bondo]

Re: Mercruiser 470 170hp questions

rodbolt = rodbolt1.0 ? Same person? Is that you Tom

Ayuh,........

That was My question,..... Til I read a post or 2,........

No Doubt that's our Rodbolt...............