Help-I'm an Idiot/ info on 470 3.7L merc sterndrive

[rongway]

Well first off I'd like to know how to post this and the question is-Does anybody know anything about the 1985 3.7L 470 Mercruiser sterndrive? I found a boat cheap but the owner says it runs good but has blow by. Is this motor powerful enough in a 18 foot bowrider type boat? And would it be justified to overhaul the motor? A mechanic said the motor was junk from the git go??

 

[aerwin]

Re: Help-I'm an Idiot/ info on 470 3.7L merc sterndrive

It has been awhile since mercury used that engine. that is not a whole lot of power. but it depends on what you are using it for. for skiing that is not alot of power, fishing, ok. was that engine a v-6 , inline 6 for 4 cylinder, for a v-6, the logical choice would be to put in a 4.6 liter. unless the block is cracked or in bad shape almost anything is rebuildible. it probably needs exhaust manifold also, $$500. to $600 if you do you own work. check this one out carefully<br /><br />Andy

 

[rongway]

Re: Help-I'm an Idiot/ info on 470 3.7L merc sterndrive

Thanks Andy, it is a 4 cyl. engine. Seems like a nice boat, would like to use it for skiing/tubing if it will do it and for fishing too.

 

[alcan]

Re: Help-I'm an Idiot/ info on 470 3.7L merc sterndrive

Hi rongway<br />I think those engines are ok. <br />The trouble is most people buy them with the promise of economy. Easy on fuel, etc. Then they run the living guts out of the thing trying keep up with the big dogs. So tell me, why do you think this rig is being sold so cheep?

 

[Trent]

Re: Help-I'm an Idiot/ info on 470 3.7L merc sterndrive

My thoughts only<br /><br />The 470 gave its share of trouble. Two oddball systems. First the charging system is "Micky Mouse" They used a water cooled voltage regulator and a stator built around the crankshaft, both give trouble and both cost lots of money to replace. The good thing is their is an aftermarket kit to install a alternator if their is room in the doghouse. Second is the waterpump.. Its drivin by the camshaft and it leaks over time and can leak water into the engine. You can repair, but somtimes its a pain to get them to stop. <br />Its also a closed cooling system which over time costs more money to repair than other raw water systems. Over all they run pretty good.<br /><br />Would I have one..........NO

 

[Terry G.]

Re: Help-I'm an Idiot/ info on 470 3.7L merc sterndrive

I bought a MCM 470 in a 1978 Sea Ray 14 years ago (four cylinders 170 HP) The thing nickled and dimed me to death. New heat transfer system (closed system $300) Water cooled voltage regulator ($200) Carb and fuel pump conversion kit ($450). Starter ($300) When it ran, it was terrific. But I had to spend at least $500 a year on some specific part that you could only get at a Merc place because the engine is a Ford/GM Hybrid. The engine could not dissapate the amount of heat the thing converted. Distributor ($200)...Valve Spring..... Head Gasekets..... I now have a 2000 model 4.3L V6 190 HP. Love this baby so far. Oil, gas and we're off to the lake! I read your post to my wife and she started shaking and her head started turning around and around. Hand has been conditioned to get the checkbook out anytime MCM 470 is heard in my house. Wife says to run not walk away from the 470! Now I'm sure there are many who have had great experience with the MCM 470, but not us.<br /><br />Terry G.

 

[rongway]

Re: Help-I'm an Idiot/ info on 470 3.7L merc sterndrive

Hey alcan, thanks for info. I think it's cheap for two reasons. It sat outside all winter(michigan) and I think the fact it has blowby scares people. It's really dirty but seems solid. They only want 1000.00 for it.

 

[trevorcday]

Re: Help-I'm an Idiot/ info on 470 3.7L merc sterndrive

The 470's were kind of a replacement for the inline 6 motors before the V6's came out. They filled the HP gap between the 4 and 8 cylinder motors. They are a really big displacement 4 so they tend to vibrate. They have good low end torque and a lot more power than the little 2.3/3.0 L 4-cylinder. Trent mentioned the charging system is expensive to fix, which I agree with, although it probably seemed like a good idea at the time. If you are looking at boats in the $1000 price range your choices will be pretty limited. With that in mind I wouldn't rule out a 470.

 

[ODDD1]

Re: Help-I'm an Idiot/ info on 470 3.7L merc sterndrive

A word of advice, rongway....the pistons in the 3.7 have been changed numerous times for durability/cost reasons...if you open it up for a 'simple repair' you may end up buying all new pistons and a bore job...

 

[macdaddy]

Re: Help-I'm an Idiot/ info on 470 3.7L merc sterndrive

Ive had 2 470,s and a buddy still has one we have never had 1 penny,s worth of trouble. I used mine 2 years (hard) and it still runs good. I could get just about 50 mph with me my wife and 3 kids in it. If this helps

 

[DJ]

Re: Help-I'm an Idiot/ info on 470 3.7L merc sterndrive

rongway,<br /><br />The 470 had an aluminum block designed and cast by Mercury Marine. The head was cast iron and is standard Ford issue from a 460 cid. Only one of course.<br /><br />The 470 was plagued with some of the problems listed above. Most of these problems were from the hang on parts. Once you get the charging system changeover done and the water pump fixed they were good engines. You may be lucky and this one already has an external alternator. <br /><br />Their large displacement for a four cylinder made them a little rough at idle, but they were real stump pullers. The drive was standard issue MerCruiser and handled the load well.<br /><br />It's probably worth rebuilding if the blow by is verified.<br /><br />These engines were VERY popular as twins in larger boats. They gave almost the same power as some small V-8's and they were half the size and weight of a V-8. The closed cooling system also made them popular in salt water. In this case, the engines usually outlasted the drives.<br /><br />I have seen some take out engines for sale on e-bay.