is 1987 Mercruiser 470 liability

[lashad]

Good evening
I am in process of of purchasing 1986 carver with twin mercruiser 470
Engines were replaced in 2009 and have under 150 hours.

I will be using the boat on a small lake with no more than 40 hours each year

I have heard lots of not very good things about this engine, but of course no one ever posts anything positive.

Am i purchasing a liability?

It seems that most issues are associated with very high hours and overheating to do 3" exchange.

any feedback would be appriciated

 

[matt167]

Re: is 1987 Mercruiser 470 liability

The engines themselves are powerful for their size and was a decent design by Merc, good enough that Ford Racing started to partner for them in '86 and put the block in the FRPP catalog for winter 1986 but Merc dropped the engine from the linup before anything really happened.. They do however have their drawbacks. Open deck design so if you get them hot, you can bet that it will need head gaskets. Camshaft seals leak, charging system is mediocre but upgradable.. Mercury has basically forgotten about them and most of the internals are NLA. They run a Ford 460 rotating assembly/ head with a special cam and crank shaft, and both of those parts along with the timing sets are NLA

 

[MarkSee]

Re: is 1987 Mercruiser 470 liability

Am i purchasing a liability?

Basically, yes you are.

There are a couple of guys on the forums here who really like that motor and by what I remember, maintain them well and you might be ok.

Have you seen this link Don has where you can download all the 470 service bulletins and read about?
http://forums.iboats.com/non-repair-i-o-inboards/all-you-470-guys-586445.html

Mark

 

[lashad]

Re: is 1987 Mercruiser 470 liability

Thanks guys
very helpful

Lasha

 

[stonyloam]

Re: is 1987 Mercruiser 470 liability

Well rebuilt 470s are just as good as any other engine of that vintage, and should be just fine. Just make sure you install new impellers in the outdrive before you take it out this spring, and new ones every other year or so. Make sure the cooling system is in good shape and watch those temp gauges, never let it overheat and you should be fine for years. Welcome to the 470 club.
p.s. I'm one of those guys that like them :facepalm:

 

[EddiePetty]

Re: is 1987 Mercruiser 470 liability

^^^^^^
....and I'm the other one!!!

 

[lashad]

Re: is 1987 Mercruiser 470 liability

What i have learned is that the main cause for all the problems is overheating.
And because it is aluminum block it expands and things shift

what is the main cause for overheating?

 

[Don S]

Re: is 1987 Mercruiser 470 liability

What i have learned is that the main cause for all the problems is overheating.
And because it is aluminum block it expands and things shift

what is the main cause for overheating?

It's not the fact that the block is aluminum, the problem is the open deck design allowing the cylinders to move during an overheat.

The main causes of overheat are raw water pump failure, exhaust elbow plugged up, thermostat stuck, clogged heat exchanger, burned up parts in the drives cooling system from impeller failure, head gasket failure.

 

[HT32BSX115]

Re: is 1987 Mercruiser 470 liability

I have heard lots of not very good things about this engine, but of course no one ever posts anything positive.

That's not always true.

Am i purchasing a liability?

Probably

It seems that most issues are associated with very high hours and overheating to do 3" exchange.

any feedback would be appriciated

The 3" exchanger *might* be a problem if you only boat in hot weather with high (80+) ambient water temps.

The 4" exchanger evidently fixes this.

The other problems Don mentioned can ALWAYS happen.

The problems unique to the 470 are things you will have to familiarize yourself with and take appropriate action.
EDUCATE YOURSELF and either learn how to deal with them or plan to pay someone else (a LOT) to do it for you.

The engine is obsolete certain parts will be a little harder (not impossible) to obtain.

There are a LOT of people here and on other boating web forums that have them so you'll have company.

Most of us would advise you to avoid a boat with that engine installed, because there's a LOT of boats out there in "radio land" that have more modern engines and drives, that parts, service and expertise are still plentiful for.....

You'll be getting DOUBLE the "liability" with 2 of them installed. :facepalm:

Good luck

Rick

 

[artificialreef]

Re: is 1987 Mercruiser 470 liability

Did you check to see if it already has the upgrades? 4 inch heat exchanger, alternator conversion. Ask if the cam driven seals were done recently or look at the rebuild receipts. I bought a 26 ft. tiara with twins also with all of that done already (dont know about the water pump seals though) for peanuts. I bet the seller knows the motors are regarded as miserable so you can play that into your bargaining. Definately do a compression test. Some peoples idea of a rebuild is different from others. Like just a top end, or just a gasket, or even just a can of black paint. Replace you raw water impellars regardless. I dont know, i guess if i knew then what i know now i probably wouldnt have bought these. But i like the idea of twin 4 cylinders with decent hpg. Just wish i had the gm's. Mine run and run cool but havent sea trialed them yet. If your handy with a wrench and watch your temp. and the price is dirt cheap, maybe go for it. I paid 2500$ for a 1983 26ft. with good compression. Whats the length of the Carver? and let us know what you decide.

 

[artificialreef]

Re: is 1987 Mercruiser 470 liability

Dont just focus on the motors and ignore the integrity of the hull and outdrives etc. as well.

 

[lashad]

Re: is 1987 Mercruiser 470 liability

thanks for your input. I have all records since 2009. Hull is an excellent condition and boat is very clean. It comes with a trailer and bottom paint is two years old. Considering that the boat has not been in the water for last two years because owner was ill.

In 2009 the completely replaced starboard motor and a new thermostat at total cost of 5K
Also repaired port morot: wire kit -ignition, repair kit-Q jet, gasket, tune up kit, spark plugs, ...
Also new shutters.

in 2010: new batteries, new starter and new water hose.

I am looking at a purchase price of about 8k