Block replacement/ repair options merc 3.0 1970

[ricodudink]

Hello all I hope you guys can give me some good advice as I am at a loss for a moment myself.

Current situation.

I am currently restoring a boat with a 1970 Mercruiser 140 3.0 engine in it.
The history of the engine is not entirely known to me though I did have the engine running a while back.

While running I heard distinct hissing from the engine which I thought was the exhaust gasket.
I then removed the entire engine to tackle the whole engine at once.
This was the point where I knew it was all wrong with the engine.
Soon I saw wet bouchies, then water in the oil and a pretty rusty exhaust manifold.
After a pressure test, I found that the head gasket was leaking so then I removed my head and took it straight away to a machine shop to have the head rebuilt straight away.

Fairly impulsive of course because deep down I knew there would be more wrong, given all the problems found so far. So, out of hope that it was a cracked exhaust manifold, I took that cylinder head away and pressure-tested my exhaust. From there it came out that there was no problem with my exhaust and so it was really in my block. The machine shop indicated that my head was not leaking and that it was completely overhauled now.

Then I went to disassemble my block myself and saw a crack in the cylinder chamber. I can't confirm whether it's completely cracked, but I'd really just like to put a replacement block under it right away.

Given I live in the netherlands, there are very few parts/ good engines available.

Now I come to these options myself

Buy a used block, get that lower block overhauled and put my own head on it.

Buy a complete longblock and then sell my head and other parts.

Do you guys have any other options?

 

[bondo]

Ayuh,...... Find a running 3.0l motor in a rotten hull, then swap that motor into yer hull,....

 

[sandkicker]

If you value your own time and/or time using the boat, buy an all up crate engine from a reputable vendor like Michigan Motors. I never saw the benefit of putting 20 or 30 yo accessories back on an engine. Sell any worthwhile parts from the old one.

 

[Dieter]

Also if you find a volvo penta 3.0 it is the same long block. since in europe you may have less options you could also look at swapping in a merc 4.3 or later volvo penta 4.3 engine and SX outdrive (transom hole is the same)

if you want a new long block quickly look up Michigan Motorz the newer long blocks they sell will require a newer style coupler but they can walk you through it

 

[o2batsea]

Do you love this boat? I mean really love it like you don't ever want any other? Then go see your Mercruiser dealer and ask about repower packages. Don't waste any more time or money on this pile of failure. Get all new everything, have them install it and go enjoy life knowing that the engine and drive isn't going to blow up. They have attractive rates for financing so you only pay a couple hundred euro per month. That won't hurt too bad will it? If you are not in love with this boat, take that boat money that you would spend on a replacement engine and put it towards your next one.
Fancy a drive to Falmouth? There are these guys:

New 3.0L Four Cylinder Base Engine

New Genuine GM 3.0L Long Block assembly.

repowermarine.com

 

[o2batsea]

Wow there are TONS of Mercruiser dealers around Amsterdam. One of them must be able to assist. That 3.0 turbodiesel seems quite nice for new power, along with a new Bravo 3 and electronic controls.