Mercruiser 470

Some guy stepped into the shop with one of this burning oil.

Mercruiser designed, aluminium block, Ford 460 head, cooling issues, disimilar metals etc, my mech told the guy to dump it, but he wants to rebuild it anyway.
We dont have any manuals for these around here, and we need to know std crank jorunal diameters to know if it's already been worked on and therefore order the new bearings.
Does anyone has this info?

I need some practise on my technical english, remember the other thread where I said that bigger bearings was oversize? now it's clear for me.

The 470 is a Mercruiser engine by design, inline 4, block is casted aluminiun, Ford 460 Cobra heads, goes between 170-190hp depending on the carb. they came with closed cooling system, wich was one of the issues on the earlier models because the heat exchanger was too small.
Another issue was the charging system (dinastat??) was mounted on the crank pulley under the circulating pump, wich if leaked would make a mess. Conversion kits are available for this fixes. The circulation pump has it issues on itself, circulating water was separated from the block with a set of retainers, wich in case of failure would allow water into the block. It has a draining path between the 2 retainers so you could notice if service was equired by seeing water dropping through this hole

There's also the disimilar metals issue, sometimes when running too hot the piston would get stuck and you had to wait for the block to cool off to restart.

The general consensus is trash them, but some people actually claims to have gotten good service from them.
They were made from the the ending 70 to the ending 80's.

Anyway, we'll take a look at the bearings this afternoon and report back. it's sitting next to my engine parts at the shop.

anybody have a service or shop manual for these?

Thanks for taking the time for looking in the first place
Some people actually state than they are quite nice and reliable engines... go guess.

I've made several searchs on the web, I found a forum where they say the engine was a joint Mercury/Ford project, the blocks were even offered in a Ford Racing brochure once, since the deal between them broke up for they both wanted to own the rights on the design.
Some people are actually looking for these blocks to put aluminium upgraded aluminium heads and are using them on race cars, go guess again.

We have this guy at the shop with one of these tore apart in pieces, he took the crank to the machinist and he told this guy to go 0.10 in all bearings, but I'm pretty sure mains were already undersize, now he doesnt remember where he left the can with the old bearings for us to look again and we suspect the machinist didnt check either since he very unlikely has the 470s crank measures.

that deserves a big THANK YOU

it was an old manual and this is word for word, i would say if you measured the main journals and they were in this spec then yes, it is for the mains. then check for egg shaped journals for the rods, idf within .0002 then you sre good to go and would assume the crank hasnt been touched. it would be unusual to just grind the mains and not the rod journals