Mercruiser inboard swap ?

[Silvervanman]

Hi guys, was out in boat yesterday and totalled the engine. Boat is a Mariah 182 shabah ltd with a 4.3v6 mercruiser mated to an alpha one drive leg. But i now have masses of an oily watery emulsion spewing out of the Carb and out of the filter on top. Apparantely a blown cylinder head gasket or split block, anyways its scrap.
My question is, do i have to refit a 4.3v6 or would the 5.0v8 or 5.7v8 fit and would the alpha one link to it ? If i'm going to replace the engine might as well make it worth my while.
Thanks in advance.
Silvervanman

[Cupramax]

I'd go with an MPI 4.3 as a replacement if I were you, 220hp as opposed to 250 with a heavier V8. Seriously, the V8 will be too heavy for an 18ft boat.

[Dunk1982]

What Cupra said, also your Alpha will fit a V8 but you would have to check the gear ratio.

Check out here if you havent already:

http://www.mercurymarine.com/engines/inboards/inde...

And Key part as well, used to use these guys allot and they know what they are on about.

http://www.keypart.com/

There is a couple of options depending how much money you want to chuck at the boat.

[Fishtigua]

For cheap(ish) crate engines, try these guys

http://www.pauls-place.com

[Cupramax]

Second for Keypart, use them regularly for bits and bobs for my Sea ray.

[Enigma AMG]

4.3mpi would be an easy swap if you have the 1.81 alpha drive ratio.
The boat would go much better with a 5.0mpi with a 1.62 ratio you would see 60mph plus with a ss 23" with that set up but you will have to move the engine mounts for the V8. I ve got a 5.0mpi in a 19ft maxum a mate has the same boat with 4.3 carb, fuel economy is identical probably due to lower cruising rpms with the V8.
If it were me I would put a 350mag in it run smart tabs and hang on for dear life, no point in a speed boat without the speed!

[Matt Harper]

Blown head gasket = totalled engine?