[Gary Black]

Hello Guys,

Are there any straight forward upgrades to increase the power of a standard Mercruiser 3 litre? I have a new prop to install for the start of the season but was wondering if anyone can advise me on easy power gains (apart from the obvious, buying a bigger boat).

Thansk very much,

Gary

[mikeyt]

Originally Posted by Gary Black

Hello Guys,

Are there any straight forward upgrades to increase the power of a standard Mercruiser 3 litre? I have a new prop to install for the start of the season but was wondering if anyone can advise me on easy power gains (apart from the obvious, buying a bigger boat).

Thansk very much,

Gary

There's not a lot you can do to a 3 litre to provide a 'significant' power increase without going to considerable expense and reducing your reliability. Keeping it tuned and correctly propped, keeping the hull clean and reducing any excess weight in the boat is about the best you can do........ but i would consider swapping your motor for a 4.3 litre. Should be a straight swap and the Alpha one should bolt right on. That will take you from the mid - high 30mph range up to closer to 50mph and provide much more grunt.

[nglauer]

I was curious, found this old post and you mention that the 4.3L should be a direct swap? I was just curious if a swap would ever be possible on my 2001 Diablo 180. I don't plan on doing anything like this for a long time... but 4-5 years from now I may be interested in doing such a swap. My plan is to hold onto our boat and just upgrade it over time. I'd like to make the interior a little nicer one day (it's mint now... but could be more upscale with some professional help), although I have to admit that for a base model it looks a heck of alot better than some current models out there.

[Sparky]

LOL ,,,,get a bigger motor

[rainman55343]

Get a bigger motor had a 3 liter in my last boat. Not much power top end and terrible resale value. I just got a 5.0 in my new boat.

[ColoradoDiablo]

Unless your in love with your Diablo ng , buy another Mariah when your ready. Between the cost of engine and changing gear ratios in the drive , you'll be money ahead buying a different boat.
However , if you do like your Diablo as I do mine..........it is quite possible to do.
Mercruiser 4.3 package

[nglauer]

I would think that it would require a significant amount of work to fit a 4.3 in the place of the 3.0? Wouldn't a modification like this require extensive fabrication to the hull inorder to mount the motor? If going to the expense of modifying to fit a 4.3L why not step up to something larger? Has anyone seen or done a similar swap?

[Andy b]

just spit balling here, but how far could you go with this?
what sort of power could you fit in a Diablo
Would she take a small block

[Andy b]

hahahaha!
like minds same times......lol

[nglauer]

I agree, i'm in no hurry to sell or upgrade our Diablo. It is in excellent shape, and I could see a motor upgrade being possible in the future. I'm sure I could easily buy another boat - but "if" a swap was possible, why not take my paid off boat and create a river monster out of it. I'm sure a 4.3 would be fine, but i'm not sure how the cost would compare.. seems that it would cost as much as a V8.

Also - I just passed up a deal on a 98 model (can't remember make) boat that had a volvo drive and V8 - I could have picked up this boat (which i understood ran when parked) for around 400.00 cash. The motor probably needed a fresh rebuild to be safe - but i'm thinking having a donor boat would be the best route if you were going to do a swap?

Any thoughts?