swapping mercruiser 3.7l for 3.0l

[get-r-done]

I am interested in swapping engines from 3.7l to new 2008 3.0. I know I will have to buy a complete engine. My boat has an alpha1 gen1 outdrive. I am considering buying a closed loop cooling system because I am told the gen1 outdrive may not provide sufficient cooling. Is this true? Also what would need to be changed other than the coupler to make this work. I have heard the spline may be different. Please tell me what I would need to get this 3.0 to bolt up to my existing alpha 1. Another option I am considering is a 4.3l

Thanks

 

[achris]

Re: swapping mercruiser 3.7l for 3.0l

I am interested in swapping engines from 3.7l to new 2008 3.0. I know I will have to buy a complete engine. My boat has an alpha1 gen1 outdrive. I am considering buying a closed loop cooling system because I am told the gen1 outdrive may not provide sufficient cooling. Is this true?

No... Most 3.0 engines run on seawater cooling. In fact the gen I drive was quite capable of cooling 350 cu.in V8s.

Also what would need to be changed other than the coupler to make this work. I have heard the spline may be different. Please tell me what I would need to get this 3.0 to bolt up to my existing alpha 1. Another option I am considering is a 4.3l

Thanks

I think the better option would be the 4.3.. You didn't say what size boat it's going in... It's just that the 3.7 was 170hp, the 3.0 is about 140hp and the 4.3s start at 190hp now... Unless the boat is seriously overpowered now, I think you'll be disappointed with a 3.0...

Chris..........

 

[Bondo]

Re: swapping mercruiser 3.7l for 3.0l

Ayuh,...

And,.. The outdrive gearing Won't work with the 3.0l,...
But,.. It Will work with the 4.3l...

 

[get-r-done]

Re: swapping mercruiser 3.7l for 3.0l

Ok, so the 4.3 is the better choice, btw this is a 19 ft rinker open bow. What obstacles will I encounter mating the new engine to the old drive. Will it just bolt right up or do I need to change anything?

 

[achris]

Re: swapping mercruiser 3.7l for 3.0l

Ok, so the 4.3 is the better choice, btw this is a 19 ft rinker open bow. What obstacles will I encounter mating the new engine to the old drive. Will it just bolt right up or do I need to change anything?

Plenty to change... Exhaust Y pipe, engine coupler, You may have to change the yoke on the front of the drive too. Engine mounts are in different places....

Chris........