3.0 engine interchange

[Mechmagcn]

Hi all, been a while. Trying to get back to my project daily driver. When I had it in the water last summer the 3.0 was somewhat noisy, sorta sounded like piston slap. I suspect that the ski boat it came from sunk before I got it, I've found too much that points to being under water.
I have located another 3.0 that is from an OMC setup, is this the same engine just different accessories? I can buy the whole OMC setup for $300, guess I could resale the outdrive.
Thanks, Jeff

 

[Rick Stephens]

Yup. A 3.0L is a 3.0L.

 

[Mechmagcn]

Thanks, probably gonna pick it up this weekend. Don't think I can be too far in the hole for a complete engine with all accessories for that price.

 

[Scott Danforth]

the base GM 3.0 is a 1990 and older thing or a 1991 and newer thing

from there OMC, Merc or VP would bolt on their exhaust/intake manifold, carb, ignition, and accessories.

 

[Mechmagcn]

from there OMC, Merc or VP would bolt on their exhaust/intake manifold, carb, ignition, and accessories.

With that being said, I know the manifold looks different, but can the OMC exhaust manifold be used with the mercruiser downpipe.

 

[Mechmagcn]

[No message]

 

[Bondo]

With that being said, I know the manifold looks different, but can the OMC exhaust manifold be used with the mercruiser downpipe.

Ayuh,..... Trial, 'n error is the only way to test that question,......

Basically, All of the OMC stuff is useless to you,....

 

[Mechmagcn]

Basically, All of the OMC stuff is useless to you,....

Ok, one last question, is the carb going to be the same? Or will it bolt to the Mercruiser intake?
Sorry for all of the questions, just trying to see if there's enough that I can use for me to make the 200 mile round trip.

 

[Scott Danforth]

With that being said, I know the manifold looks different, but can the OMC exhaust manifold be used with the mercruiser downpipe.

NO, not easily

 

[Scott Danforth]

Ok, one last question, is the carb going to be the same? Or will it bolt to the Mercruiser intake?
Sorry for all of the questions, just trying to see if there's enough that I can use for me to make the 200 mile round trip.

you want to remove all the OMG stuff and build up with the Mercruiser stuff you have. the base long-block is the same, not the complete up-fit bobtail

 

[Mechmagcn]

you want to remove all the OMG stuff and build up with the Mercruiser stuff you have.

Well....there's part of the problem, the carb will run but has major corrosion issues in the accelerator pump bore. I'm pretty sure that the starter and alternator will work, both of mine are bad.

 

[Scott Danforth]

starter should be the same as that came from GM. wiring for alternator brand A is different then brand B which is different than brand C

 

[QBhoy]

Sorry for asking. This noise it’s making...are you sure it’s not just the usual 3.0 GM noise ? They do sound rough as toast at the top end most times. Mostly like a tapping noise. It’s their trade mark ! Some noisier than others...but bottom line...they are not the most refined of things. Compression test will tell you. Just in case it saves you a few quid. All the best.