470 Merc. Good? Bad? Ugly?

[Jakebob]

Hi All!

First post here and the last thing I want to do with my first post is start an argument. I'm really looking for honest information from folks have first-hand (or close to first-hand) knowledge.

So, here goes. I'm looking at several boats to purchase and a couple have the 470 Mercruiser motor. When I mention this, a few guys make funny faces and encourage me to keep looking. I'm wondering why.

Are there known issues with this motor? More than other Mercs? Or is it just underpowered etc?

I appreciate the help and I'm sure I'll be posting here often!

Thanks
Jake

 

[Don S]

Re: 470 Merc. Good? Bad? Ugly?

Welcome aboard Jake.
Might want to do a search on that subject, it comes up quite often.
There are several issues with that motor.
If you don't own it already, don't buy it.

 

[Jakebob]

Re: 470 Merc. Good? Bad? Ugly?

Thanks Don. I must be using the wrong search terms. I'll keep digging!

 

[Don S]

Re: 470 Merc. Good? Bad? Ugly?

They are there, hard to say for sure, I don't go searching for them.
Just to give you a few strikes against it.

1. They aren't made anymore, and haven't been around since 89
2. Aluminum block, open deck design, Cast iron Ford 460 head.
3. Overheats will most likely take out a head gasket due to open deck design of block.
4. Cam seal leaks antifreeze into engine oil (Very Common Problem).
5. Charging system with rotor and stator OB setup on front of crankshaft. Poor setup and parts not all parts available. What is available is very expensive. Regulator is about 400 bucks.
5. Requiers a kit to install a regular alternator on engine to replace OEM charging system.
6. Older ones had 3" heat exchanger. They were noted for causing overheats and should be upgraded to 4", also very expensive.
7. Exhaust risers are very expensive and some are hard to find.


When they are running, they are strong 4 cylinder engines, but they do have problems for those that don't like to or can't work on their own boats.

 

[paulspaddle]

Re: 470 Merc. Good? Bad? Ugly?

Try putting quotes around your search words...."mercruiser 470"

Here's one to get you started...

http://forums.iboats.com/showthread.php?t=285663&highlight=mercruiser+470

There are lots of threads about it....come back and tell how you feel after doing some reading....

 

[Jakebob]

Re: 470 Merc. Good? Bad? Ugly?

Perfect. Thanks guys.

 

[shouldsellit]

Re: 470 Merc. Good? Bad? Ugly?

My first boat had 470 that I still currently own. Didn't know much about it till had overheating problems and joined this forum and found out the ugliness.

Will say that if It runs good a upgraded heat exchanger is worth it. After fixing initial issues when I bought it never overheated once after installing the new exchanger.

 

[starsnstripers]

Re: 470 Merc. Good? Bad? Ugly?

"RUN" lol I think Don nailed it on the head for ya! I've heard more cons than pros on those things, IMO I wouldn't look at one personaly. Welcome Jake

 

[Bondo]

Re: 470 Merc. Good? Bad? Ugly?

Ayuh,... Welcome Aboard Jake,.... You'll see how much I just Love those beasts in that seach,.....

 

[achris]

Re: 470 Merc. Good? Bad? Ugly?

As much as it hurts me to say it, I agree with Don and SnS...

Personally, I like them, when they're running well. They do have problems with the smaller cooling system, the alternator system and the camshaft seals, but when all that's sorted out, they aren't too bad....

But unless you are capable of working on it yourself... It's going to cost you a lot to have a 'professional' work on it....

If I have to choose between the 470 and an OMC.... 470 would win every day... If I was looking around at boats.... I would walk past the 470, unless the boat is so well priced that you can afford to scrap the power plant and install a more 'conventional' engine.

Chris........

 

[Bondo]

Re: 470 Merc. Good? Bad? Ugly?

If I have to choose between the 470 and an OMC....

Donno,.... Think I'd opt out for a Canoe......

 

[q5ka]

Re: 470 Merc. Good? Bad? Ugly?

Don did a very good job describing the problems. If you are not going to do the work yourself or not familuar with engines, I would not recommend it. If you can find another similar boat with a chevy 350, I would point you in that direction. There are a few of us with these 470/3.7l motors. Most of us like them but understand that it has its problems and either spend the money to replace some problems (charging system) or are waiting until the problems show up to fix it.

Just like any motor though, how well was it taken care of? I would trust my 12 year old 3.7l over many 5 year old chevy 350 just due to I know when the oil was last changed and it was not worked very hard (or beat for those that prefer that term).

 

[guyaverage]

Re: 470 Merc. Good? Bad? Ugly?

Ahh, the 470. Take mine, for example. No, really, take it. PLEASE.

I am a 6 year boat owner, all with the same 470 powered 19ft bowrider. I had 4 very good years with this engine. Its smooth, torquey, very good on fuel, and tosses my boat and 2+ tubers around all day long like its nothing. Mine was well taken care of, and when I bought it (I knew the owner's son) I maintained it religiously, new oil/plugs/impeller every year, acid-cleaned the heat exchanger every spring, converted the charging system to a marine alternator, etc. I have not found parts to be difficult to find at all.

Best of all, its easy to work on. Which is good, because for the last 2 years thats about all I have done with it.

Cracked exhaust manifold (upgraded to aluminum - $$$)
Blown head gasket (I never even overheated this sucker!)
Fuel pump
Upgraded to a regular marine alternator
Water pump seals
Carb rebuild
Worn out distributor shaft
etc
etc
etc

The economy is a mess and people are dumping boats all over the place. There are way too many 3.0, 4.3 and 5.0 powered boats out there right now to consider one with a 21+ year old 470 in it. If Merc had put a regulator alternator on it, a regular water pump, and put an aluminum head on it, it could have been a great engine. But they didnt. Now its just old, quirky maintenance monster with diminishing support and a whole fleet of mechanics who quiver in fear when you even ask a question about one.

Take it from someone who owns one of the 'better ones'. There are a few out there with some life left in them, that run good, and have given good service and will for a few more years. But I would never, ever recommend one to anyone else. Thats the nicest I can put it.

 

[zbnutcase]

Re: 470 Merc. Good? Bad? Ugly?

The sad fact is now that they have been out of production for 20 yrs you CAN put an aluminum head on it, installed with studs, which would help in the head gasket department. 'nutcase

 

[Don S]

Re: 470 Merc. Good? Bad? Ugly?

The sad fact is now that they have been out of production for 20 yrs you CAN put an aluminum head on it, installed with studs, which would help in the head gasket department. 'nutcase

And after all that expense, you then have a 470 with an expensive aluminum head, but you still have a 470 with all the other problems.

 

[cr2k]

Re: 470 Merc. Good? Bad? Ugly?

it's GOOD that you asked, because the UGLY motors are BAD.

 

[HT32BSX115]

Re: 470 Merc. Good? Bad? Ugly?

Welcome aboard Jake.
Might want to do a search on that subject, it comes up quite often.
There are several issues with that motor.
If you don't own it already, don't buy it.

Jake,


Your best bet? DON'T BUY A BOAT WITH A 470 INSIDE!




Cheers,


Rick

 

[rodbolt]

Re: 470 Merc. Good? Bad? Ugly?

the headgasket issue wasnt studs or head materiel, it was the open deck design.
open deck simply means NO metal at the top of the cylinder tube to aid in stabilizing the top of the cylinder liner. means it moves and eventually cuts the gasket.trust me you dont have to overheat a 3.7 to pop a head gasket OR crack a manifold.

 

[Jakebob]

Re: 470 Merc. Good? Bad? Ugly?

Wow. After reading my search results and all this, I'm officially crossing it off the list.

I have a lot of experience with cars and I know that there are plenty of cars, motors, and transmissions that develop a bad reputation but a lot of that is from people who have never owned or worked on one, and are parroting rumors. This doesn't sound like one of those cases.

 

[rodbolt]

Re: 470 Merc. Good? Bad? Ugly?

ME ?
I owned one, two if you consider it my first and last.
worked great the first two years then I went down the road.
funny thing the guy I sold it to ran it another 5 years and did nothing to it until it sank one night.