Can you help me identify this engine?

[schwim]

The boat is a 1991 Chaparral 1800SL It's been sitting for years. I'm pretty sure the engine is going to be junk(it sounded like a diesel when I heard it run, tons of knocking) but I'd like to know what it is so I can research either parts or swappable replacement engines. I don't see any model designators on the engine but I might be missing them.
Any help Identifying would be greatly appreciated. Let me know if there's any better info I should be providing.

 

[Bondo]

Ayuh,...... Welcome Aboard,....... That's a 3.0l Merc motor, probably with an Alpha 1 drive,....

 

[schwim]

Ayuh,...... Welcome Aboard,....... That's a 3.0l Merc motor, probably with an Alpha 1 drive,....

Thank you very much! I was considering finding an engine to drop in while figuring out if I could rebuild what I have, is this comparable to automobiles where there's only a very limited range of engines that are swappable or is it more standardized?

I'm only familiar with autos, where I've had to use adapter plates, mounts, conversion TCs or clutches and flywheels.

 

[Scott Danforth]

3.0 liter motors were NEVER used in automobiles.

they are one of GM's industruial motors

find another 3.0 marine motor to drop in its place. the 3.0 is the entry level I/O motor. when it comes to 3.0 liter marine motors, 1991 is the dividing line. find a 1991 or newer and it will drop right in. skip the 1990 and older.

how is the hull on you 35 year old boat?

 

[schwim]

3.0 liter motors were NEVER used in automobiles.

they are one of GM's industruial motors

Sorry for not being clear, I didn't mean I was familiar with a marine-use engine in automotive applications, I was trying to say I'm only familiar with engine swaps in automotive applications and was wondering if marine engines were more standardized, mounting to the outdrive or whether I needed to stick with the same make/model(thank you for clarifying year divide).

how is the hull on you 35 year old boat?

It seems fine. It was in use by a family every summer from new until I bought it 5 years ago. Unfortunately, we moved immediately afterward and I never got a chance to use or work on it as some life happened.

 

[Scott Danforth]

Do some core samples. The pics suggest that there is most likely a few soft spots in the floor which means the stringers and transom are rotten

 

[Bondo]

Sorry for not being clear, I didn't mean I was familiar with a marine-use engine in automotive applications, I was trying to say I'm only familiar with engine swaps in automotive applications and was wondering if marine engines were more standardized, mounting to the outdrive or whether I needed to stick with the same make/model(thank you for clarifying year divide).


It seems fine. It was in use by a family every summer from new until I bought it 5 years ago. Unfortunately, we moved immediately afterward and I never got a chance to use or work on it as some life happened.

Ayuh,....... Boat motors are basically more standardized, sorta,......

The boat I've been putterin' on, started out with yer motor, 'n drive,.....
Now it's sporting a 350/ Alpha 1 drive,......

Yer choices for a drop-in motor is a 2.5l, or the 3.0l,...
Any other choice, can be done, but with more work/ parts,.....

 

[zke61553]

The boat is a 1991 Chaparral 1800SL It's been sitting for years. I'm pretty sure the engine is going to be junk(it sounded like a diesel when I heard it run, tons of knocking) but I'd like to know what it is so I can research either parts or swappable replacement engines. I don't see any model designators on the engine but I might be missing them.
Any help Identifying would be greatly appreciated. Let me know if there's any better info I should be providing.

The cylinder block nameplate looks like an old OMC Cobra! The knocking sound might be due to the detachment of the connecting rod bearing