Mercruiser 140 busted.. got a donor engine, decoding serials..

[rbuljo]

hi guys, first time i`ve posted here. been reading alot since i got my first boat 1month ago.

i have a 1985 Draco 18 suntop with the Mercruiser 140 engine and alpha one stern unit.

but the cylinder block is busted, leaks both water and oil. suspect previous owner neglected to prepare for the winter.

got my self a donor engine, year unknown, it is the same engine (i hope), but i was curious regarding the year it was made and if there are some differences.

first thing i noticed are the choke, on my busted engine it is electrically engaged, on the donor engine it got a hose coming in..?`

original engine serial # A401501
donor engine serial # 4648980

can someone help me decode these numbers? also, some tips on what to buy as i am rebuilding the engine.. want to change the connecting rod bearings and the crankshaft bearings. remember reading something about buying those parts from GM instead of a marine shop.?

Regards from Norway!

 

[achris]

Re: Mercruiser 140 busted.. got a donor engine, decoding serials..

Original engine (0A401501) is 1985...
Donor (4648980) is 1977...

If you don't want to buy 'marine' bearings, then a premium quality bearing will do the job....

Chris........

 

[rbuljo]

Re: Mercruiser 140 busted.. got a donor engine, decoding serials..

thanks! so regarding buildup, i would use the cylinder block from the donor. and get everything else from the 1985 engine..? or is it no differences on these engines? i got the donor laying in parts on the workshop floor. so i am eager to start building it together.

what car to use for reference regarding parts for the connecting rods etc?

thinking i will use the cylinder block, with pistons etc from the donor. and the head from the 1985 engine.

 

[Ryanlewis2010]

Re: Mercruiser 140 busted.. got a donor engine, decoding serials..

make sure you check the bore thou because the donor being so old might have ben bored .030 over also ya there is no REAL marine bearings, They are just the same with marine added on for a bigger price tag when you buy from a marine shop. That is coming from my marina that was being honest and saved me a boat load of money. and i still got a strong running motor.

 

[achris]

Re: Mercruiser 140 busted.. got a donor engine, decoding serials..

Heads should be the same...

 

[Fishermark]

Re: Mercruiser 140 busted.. got a donor engine, decoding serials..

twhat car to use for reference regarding parts for the connecting rods etc?

The 3 liter Mercruiser is not a car engine used in a boat, but rather an industrial engine. Not sure about Norway or course, but many auto parts stores here (like NAPA), carry a marine catalog for these parts.