Someone Please help I am in need of 3.0 block

zebrex

Cadet
Joined
Aug 18, 2009
Messages
18
I just discovered that the previous owner did not disclose that the block was cracked behind the exhaust manifold. He did a nice job of JB welding it but it appears that there is a water jacket and oil passage somewhere on the inside that are getting together. I am finding oil in my bilge and the engine oil on the dipstick has a bit of a milky hue. I cant afford a long block. Its an 82 OMC stringer 3.0 I believe a 3.0 block from a mercruiser, volvo, or OMC are the same. Where can I find one.
 
Joined
Aug 26, 2007
Messages
71
Re: Someone Please help I am in need of 3.0 block

We live and die finding 120s/140s on craigslist.com for restoration projects. Like you noted, these engines were common from several brands, Mercruiser being the largest. Hope this helps you out.
 

intrepidvoyager

Petty Officer 1st Class
Joined
Mar 24, 2009
Messages
216
Re: Someone Please help I am in need of 3.0 block

sometimes cheaper to find an old trashed boat and buy the whole boat to get one. You should be able to get a reman short block for 2K but watch out where it comes from ...there are some horror stories on line ...good luck.
 

elkhunter338

Master Chief Petty Officer
Joined
Jun 27, 2009
Messages
818
Re: Someone Please help I am in need of 3.0 block

Most of these used blocks are junk, they come from boats. There are atleast two different engine blocks, one with a one piece rear main seal and one with a two piece rear main seal. I am not sure about the 1984's. But if you are going to use your old engine parts you need to make sure your blocks are the same so you can use the crankshaft and other parts that are specific.
I had what I think is a bad block in my 140 and figured finding a good block was almost impossible. The rebuild shop was willing to rebuild my old block but the cost was getting close to a brand new engine so I spend the $3,000 to buy a new motor from Michigan motorzs. I would not buy a rebuilt boat engine because you do do not know what you are getting. Engine block conditions can vary from good to bad. Most 140's are not cooled by antifreeze so the engine block could see salt water, freezing.
 

zbnutcase

Commander
Joined
Sep 19, 2009
Messages
2,055
Re: Someone Please help I am in need of 3.0 block

Yup finding a used block is nearly impossible because they were never used in an automotive app in this country. And a freeze crack on manifold side will not cause water in oil. In fact I have seen these run forever with a crack there with no ill effects. 'nutcase
 

zebrex

Cadet
Joined
Aug 18, 2009
Messages
18
Re: Someone Please help I am in need of 3.0 block

ok I need to figure out if my block is fixable or not. I also need to figure out if my 82 has a 2 piece rear main or not
 

intrepidvoyager

Petty Officer 1st Class
Joined
Mar 24, 2009
Messages
216
Re: Someone Please help I am in need of 3.0 block

the problem with this issue is where do you stop re rebuilding your block ..even if your block is fixable are you going to put new pistons/rings etc in a block of dubious integrity ...and what about crank and rod bearings and maybe a crank regrind, cam bushings, etc etc ... As a previous post said a lot of blocks from rebuilers are also of unknown integrity ....just check the web for horror stories. However, if not abused these engines are bullet proof. A friend in Hawaii has one in his fish boat .... no idea on hours but its 7 years old and he's out fishing virtually every day .......They are the industrial version of the iron duke of which GM made zillions.

Can't think of one instance where it made more sense to reman than to get a new short block.

Also you can try the forklift guys in your area .... the 3.0 was also used in lots of forklifts.

I know its a bummer ..... good luck anyway
 

elkhunter338

Master Chief Petty Officer
Joined
Jun 27, 2009
Messages
818
Re: Someone Please help I am in need of 3.0 block

Can't beat the price of a new motor. $1999 plus shipping.
And in your application since pre 90, you will need a 12.75 flywheel, new engine coupler, plus dist. (new $100). I went this route 2 years ago. This engine does not come with the manifold/carb. You reuse your old manifold/carb. If you have a large ports on your manifold you will need a special gasket(no big deal). This engine comes with water pump, valve cover, oil filter, oil pan.
Also I had to rejet my carb. because it was burning too rich with the new motor. I had 50/51 jets, I thought this was odd, but once I rejeted the carb the plugs burn nice and clean.
I bought mine from Michigan Motorz.
The only thing that happened to me is the bolts that bolt the flywheel on where a few thousands to thick and I had to grind a few thousands off the bolt heads so they did not hit the bell housing. This caused me to pull the motor back out of the boat because I had a noise and it ended up being the bolt heads that bolt the flywheel on. I ground a few thousands off the bolt heads and all has been great since then. I run in salt water so I have antifreeze in the engine block. Now have 140 hrs on the motor and it does not burn a drop of oil.
 
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