Mercruiser 110/120 swap?

T

tcooke

Petty Officer 2nd Class
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Mar 20, 2008
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I have a 1965 Merc 110, cracked block. I haven't been able to find another 110 so my querstion is......can I get a 120 and swap it with my 110? will it bolt up to the sterndrive assembly or would I need the whole package? If that is the case any chance a 3.0L would drop in?

Thanks in advance.
 
Bondo

Bondo

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Re: Mercruiser 110/120 swap?

can I get a 120 and swap it with my 110? will it bolt up to the sterndrive assembly or would I need the whole package? If that is the case any chance a 3.0L would drop in?
Click to expand...

Ayuh,...

They Should drop right in,+ Bolt up,... But there maybe a few fitment issues,...
 
achris

achris

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Re: Mercruiser 110/120 swap?

A 120 or a 3.0litre should drop staright in. The 110 and the 120 are both 153cu in engines, and the 181 (3.0litre) has the same external dimensions. The only place I can see that you could run foul is the drive gear ratio. I don't have my charts handy, but you should check them.

Chris........
 
chiefalen

chiefalen

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Re: Mercruiser 110/120 swap?

Your better off with the 3.0 and heres why, parts are easier to get, and it's a more widely used motor nowadays.

The flywheel and coupler will have to be moved over i believe, nothing major there, i don't know about the exhaust pipe issue but they make all kinds of adapters, my humble opinion a 3.0. 140 if you can get a good running one.

You will love the extra power, and i believe the gear setup is the same no need changing them.

Good luck !
 
Faztbullet

Faztbullet

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Re: Mercruiser 110/120 swap?

Flywheel and coupler wont interchange from old 110 motor to newer 3.0 motors, different crankshaft and mounting pattern. (1 piece vs 2 piece rear seal) The gear ratios are the same.
 
chiefalen

chiefalen

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Re: Mercruiser 110/120 swap?

I posted a 140 3.0. But will the pre 90's motor fit the flywheel and coupler.

Or could a hole be drilled in the flywheel. You would have to put the flywheels side by side to be sure ??

As to a drop in nope.

It can it be made to fit.
 
T

tcooke

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Re: Mercruiser 110/120 swap?

OK, so if I decide to run a 3.0L, what would I need to get it ot fit? I am somewhat of a newbe when it comes to boat motors/couplers etc.. Would I be looking to find a special flywheel/coupler in order to get it to fit, what about an old 3.0L would it have a flywheel that would work in my favour?

If I am not mistaken I think my gear ratio is 1.63:1 (sound right?)
 
Bondo

Bondo

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Re: Mercruiser 110/120 swap?

Or could a hole be drilled in the flywheel. You would have to put the flywheels side by side to be sure ??
Click to expand...

Ayuh,... It don't work that way Chief,...
The crankshaft bolt pattern on the Old style flywheels is 3, 1/4" circle,....
The New style is 3" circle...
OK, so if I decide to run a 3.0L, what would I need to get it ot fit?
Click to expand...

Ayuh,... A Pre-1980 would be your Best option....
Between 1980,+ 1990, it will be Adaptable....
Post-1990 will Not work....

You'll need to get 1 With it's Flywheel, as the 2.5l motors are Internally balanced,.....
And,..
The 3.0ls are Externally balanced....
 
T

tcooke

Petty Officer 2nd Class
Joined
Mar 20, 2008
Messages
112
Re: Mercruiser 110/120 swap?

Ok, so if I found myself a pre-1980 3.0L with the flywheel it should slide right in then.....Anyone have a pre-1980 3.0L for sale;)
 
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