How bad is a 470, really?

[nola mike]

Ok, I didn't even know about the "quirks" of this engine until recently, and I have some idea of the responses that i'll get to this, but I've read a lot about it here and on other forums. Despite the negative rep, I'm still considering buying a boat with one of these. Reason being, in the price range i'm looking at, I think i may be better off taking my chance on a boat/motor that has been obviously well taken care of/maintained than on a more 'reliable' powerplant which has been more abused. Anyway, I want a clear idea of what i'm getting into. The major issues that i've seen with this engine, at the end of the day don't seem like a big deal. Seems like this wasn't merc's finest design effort, but i'm still not convinced that it's a deal-breaker, if all else is right.

1. Charging system. ok, it sucks. Seems like an easy/not too expensive fix to retrofit an alternator.
2. Cooling system: Again, it sounds like the cooling issues are not as pronounced with an upgraded heat exchanger (when did the 4" become standard?), which is pricey to upgrade, but again, not insurmountable.
3. Cam shaft seal: This seems like the worst and priciest failure point. I haven't been able to get a good handle on what this costs in terms of time/money for a diy'er. Seems like the engine can stay in to do the work if there's room in the front to work, but the one guide I saw called for special tools costing $500 or so. Looks like i should look for a coolant leak at the front of the engine (somewhere?) to assess.
4. Parts availability: Which parts in particular are we talking about?
5. Lastly, should the engine need to be rebuilt, it seems like it would be better to replace it with a more traditional engine. I've seen some info on needing to mod motor mounts, but again, i'm not sure about the difficulty involved in this. For my application (~19' bowrider), a 4.3L seems like the best replacement.

What else am i missing?

 

[bhammer]

Re: How bad is a 470, really?

I was a fan of the engine and had good times with mine. Like you, I came here looking for info on the charging system, and I got back tons more than I expected in "feedback" If you are mechanically inclined then it is not a bad engine. I don't thik that I would tell someone to buy a boat with the engine though. There have to be more boats in you $$$ that do not have the 470.

1. I never had a problem with mine and did not do the alternator conversion. I kept a good eye on my guage to tell me if it was working.

2. Yes, you want one with the 4" heat exchanger.

3. I did mine and it was under $100 and had to do it twice because I got the aft seal in the wrong place. It took a Saturday afternoon and I had easy access to everything. I just loosened the oil pan screws so I could get clearance to get the timing cover off.

4. The charging system is the only one I have ever heard of that are hard to get. If you have a problem, just do the upgrade as it is cheaper than the voltage regulator that is the main reason for failure, followed by the magnets coming off the balancer. Just rememberd that the timing cover was no longer available as well. I am sure you will hear more.

5. Can't help you with this one but would assume that you would need to mod the engine mounts. Weight of the V6 might be an issue as well.

 

[HT32BSX115]

Re: How bad is a 470, really?

What else am i missing?

The 800 lb elephant in the room.

In this economy, there's literally thousands of boats, engine, drives for sale that are still fully supported by Mercury, Volvo etc.

Why buy a boat with a Merc 470, OMC 460 King Cobra, Yamaha drive, Scott Atwater, or other "boat anchor" when with a little effort you can get something far better supported in the aftermarket?


You asked....


Good luck!


Rick

 

[TilliamWe]

Re: How bad is a 470, really?

Mike, your logic is not bad. A properly maintained engine (obsolete, with known problems) is a better choice than an abused engine.
It's just that all those known problems add up to a lot of dollars when they go bad. Is that in your budget?

 

[45Auto]

Re: How bad is a 470, really?

When you go to re-sell it, you've eliminated almost every buyer who has done any kind of internet background research on the boat/engine combo (except for people like me and you). You'll have to find a total clueless newbie who doesn't know anything about the engine, or else someone willing to work on it.

Wouldn't bother me any to pick up a boat with a well-maintained 470. Like you, I'd know what I was getting into. But it would have to be MUCH cheaper than the same boat with a different motor.

 

[nola mike]

Re: How bad is a 470, really?

Mike, your logic is not bad. A properly maintained engine (obsolete, with known problems) is a better choice than an abused engine.
It's just that all those known problems add up to a lot of dollars when they go bad. Is that in your budget?

well, hopefully not. but i'm buying a 20 year old boat. there can/will be problems with any engine that old. the potential is always there for an expensive repair. how do i know my rock-solid 4.3L isn't 30 hours away from a rebuild, or springing a leak in the lower unit, or blowing a manifold, etc? and really, how do i know the true condition or the maintenance history of something this old? charging problems, or needing a new heat exchanger is not in the same league as "this engine has a tendency to randomly throw a rod" or "lower unit occasionally eats gears and needs replacement". these problems, although known, don't seem like the worst thing that can happen to a 20y old engine--if something breaks at this point, it's because it's old, not because it's poorly designed. despite what people here are saying, it actually ISN'T easy to find an older, well-maintained, good condition boat on the cheap (yeah, i know there's a reason for that)--especially if i'm looking for a little more power than a 3.0L. i've been looking for 2 months now, and am anxious to get on the water. if finding the "perfect" boat costs me the summer, THAT isn't worth it.

 

[Bondo]

Re: How bad is a 470, really?

how do i know my rock-solid 4.3L isn't 30 hours away from a rebuild, or springing a leak in the lower unit, or blowing a manifold, etc?

Ayuh,.. The difference is the Availability of Parts,+ the Knowledge base to Fix it.....

Worst case scenario,..
A 4.3 Blows up,... A $100. Junkyard motor will get you back on the water....
A Blown 470,... You'll be Paddling....

 

[whatsagm]

Re: How bad is a 470, really?

I bought a boat about 2 months ago with a Blown up 470. I just rebuilt the 470. Parts are not that hard to find. I fixed my camshaft seal problem by having the cam welded with a material that the seal won't eat into. I also bought a 4 in heat exchanger. I am going to upgrade my charging system when it fails. I love my 470. easy to work on great power. My 18 ft boat keeps up with my buddy's 4.3L in his 21 ft boat. If you can fix your boat yourself buy the 470 but if you can't then look at other options. Over all i love my 470.

 

[cooter2506]

Re: How bad is a 470, really?

I looked for months to find the correct boat for me. Engine package and size I wanted. I didnt settle. I drove 300 miles one way and mand was it Worth The Trip. Henece the name on the back. My wifes uncle has a 470 and loves it but I know of 4 or five others that have them or have had them and hate them. But all in all it is up to you. Anything is possible. Rebuild it or replace it with something else if the boat is in that good of shape. Personally I would look around for a bit longer and maybe extend my search area.

 

[nola mike]

Re: How bad is a 470, really?

Ayuh,.. The difference is the Availability of Parts,+ the Knowledge base to Fix it.....

Worst case scenario,..
A 4.3 Blows up,... A $100. Junkyard motor will get you back on the water....
A Blown 470,... You'll be Paddling....

gotcha. which is why i asked:

5. Lastly, should the engine need to be rebuilt, it seems like it would be better to replace it with a more traditional engine. I've seen some info on needing to mod motor mounts, but again, i'm not sure about the difficulty involved in this. For my application (~19' bowrider), a 4.3L seems like the best replacement.

and really, seems like i'd actually have better luck with the 470 on this one...ya know, since they're all boat anchors anyway, i might have better luck finding one whilst paddling home

 

[q5ka]

Re: How bad is a 470, really?

I have one and love it. Again, I turn my own wrench and familiar with 4 cylinder engines that are half a 8 (also have Porsche 944). These type of motors tend to have good power for the weight. There is also Breezeworks.net that will give good info/parts about these engines. Most people wont recommend the 3.7/470 as they are different. They have their problems which sounds like you got the just of them. I would recommend to look again at other boats for the same price because you can get a great deal on about anything. If you still thinks this is right for you, get it.

 

[TilliamWe]

Re: How bad is a 470, really?

nola, as far as knowing if a motor is 30 hours away from a blowup, do a compression test, oil analysis, and look at the oil pressure. That's the same for every motor.

Hey, whatsagm, what did all that stuff you did cost you? And yeah, I guess an 18' boat with 170hp would keep up with a 21'er with a 4.3. (you don't say if it's a vortec era MPI engine at 225hp or anything, so it could be as low as 165hp) Hardly a good benchmark for your boat being a rocket.

 

[TilliamWe]

Re: How bad is a 470, really?

(also have Porsche 944).

Is that Union made? (inside Central Illinois joke for everyone else!)

 

[nola mike]

Re: How bad is a 470, really?

Well, I did it. You can all laugh at me later when i'm asking for advice on how to fix it.
The boat was in such great shape, and obviously so well taken care of, that I couldn't pass it up. Hit 50 mph on the test drive. No leaks, the engine looked brand new. Owner said that he had never had a prob with over-heating, all charging system was original, 4" heat exchanger. 150+ psi in all cylinders. I paid $700 or so less than i would have with a 4.3L, which I thought was fair. And I just love the Glastrons. I guess we shall see...
If nothing else, at least I think I made an informed (though some here would say misguided) purchase. And I get to be on the water this weekend!

 

[deerslayer303]

Re: How bad is a 470, really?

Well I own one too, and had never seen one before I bought the boat, heck I didn't even know if it ran. Well it does and runs QUITE well actually, so I'll give it a wirl.
And you know if I quite using stuff that is obsolete I would not have any fun.
I ride a motorcycle that is 28 years old and parts for it are made of UNOBTAINIUM but you know what its taken care of and runs like a sewing machine. I can turn my own wrenches and if the 470 buys the farm, I'll fix it. Most people want to just buy a boat, put gas in and go. But I have way more fun and usually save a boat load of money by buying something old and making it useable. just my .02

 

[IVAZ]

Re: How bad is a 470, really?

And you know if I quite using stuff that is obsolete I would not have any fun.

Im going to borrow a line from Howard Sterndrive "The fun is in water skiing, tubing and general boat performance".

Fixing a boat is not the worst thing in the world but, remember we bought our boats to get them wet not work on them. The good thing is that you both are members in the best forum when it comes to advice and support for all boating needs.
I wish you both happy times and a long life span for your engines.

 

[MikDee]

Re: How bad is a 470, really?

Well, I did it. You can all laugh at me later when i'm asking for advice on how to fix it.
The boat was in such great shape, and obviously so well taken care of, that I couldn't pass it up. Hit 50 mph on the test drive. No leaks, the engine looked brand new. Owner said that he had never had a prob with over-heating, all charging system was original, 4" heat exchanger. 150+ psi in all cylinders. I paid $700 or so less than i would have with a 4.3L, which I thought was fair. And I just love the Glastrons. I guess we shall see...
If nothing else, at least I think I made an informed (though some here would say misguided) purchase. And I get to be on the water this weekend!

Well good for You! You got an education, and a heads up here, you knew the pitfalls, but got it anyway. A lot has to do with how an engine was maintained, and it sounds like "cherry!" I was always impressed by the compact power of that engine, sometimes I've gone against the norm. myself and been lucky, I hope you are as well, so Good Luck & Happy Boating!

 

[mkast]

Re: How bad is a 470, really?

remember we bought our boats to get them wet not work on them.

You are missing out on the instant gratification one gets from some top shelf wrenchin'.

 

[solar7647]

Re: How bad is a 470, really?

As long as it hasnt over heated and it was taken care of it should be fine. The parts arent to hard to find but can get up there in price since many internal parts arnt made any more. Mine is all origanal but was well maintaned and still is and runs great. I find that the more people screw with them the more tempermental they get.

 

[IVAZ]

Re: How bad is a 470, really?

mkast,
Gratifying to me was teaching my kids to ride a bike or watching my youngest win a spelling bee after we practiced for two weeks.
Fixing my boats issues has only ended the scraped knuckles and money spending. If it makes you or any other fellow get warm inside, power to you.
Different strokes for different folks.