New Bigger Engine

[Bigplumbs]

I had a simple Idea (I am like that) and wondered if it would be mad or indeed if anyone has done this:

My Fletcher 19 GTS has the 3 ltr Mercruiser on an Alfa 1 Gen 2 leg. The engine is only 2 years old (fitted by previous owner) and was bought from Repower Marine and is fine. As with most people I would quite like more power. The 19 GTS was also fitted with the 4.3 ltr MPI engine and I was wondering about putting in the 4.3. Repower marine hav the base engine for £3600 and I was wondering how much more you need to pay to in effect have the complete engine.

I was wondering if any of you have upgraded from the 3 ltr to the 4.3 MPI and if so what do you think.

Dennis

 

[Richardcm]

Might be worth asking on here http://forums.iboats.com/forum

 

[spannerman]

If the engine will fit it should be no problem, it may sit a little lower at the stern due to the heavier block. However the gear ratio in the drive most likely will be wrong as the bigger engine has more hp so its worth finding out what ratio you have now, its usually stamped on the port side of the upper gear housing after th serial nr, otherwise you can turn the engine one turn by hand and see how much the prop rotates in gear. Even if the ratio is compatible you will definitely need a new prop.

 

[rafiki_]

Probably cheaper to buy a Fletcher with the bigger engine installed?

 

[BruceK]

The standard gear ratio for the 175 hp 4.3 is 1.81:1 where as currently you should be running a 1.93: 1.

 

[wipe_out]

Probably cheaper to buy a Fletcher with the bigger engine installed?

I would have thought that would be the cheaper option too..

 

[Spi D]

Also need to factor in that engine mounts are not the same, so alterations needed to the boat. As the engine is wider you might need to move other parts.

If switching from carbed to EFI the electrics might take som alteration too, e.g. engine tachometer will need to be adapted to 6 vs 4 cyls. (possibly by settings).
The prop most likely will need to be replaced, depending on the gear ratio.

 

[benjenbav]

I guess a bit like re-powering a car but worse: once the old block comes out nothing quite fits with the replacement block or, if it does, it still needs to be replaced because you notice the wear and you might as well do it now whilst the engine is out, to save a further engine-out a little way down the line.

 

[Spi D]

I guess a bit like re-powering a car but worse: once the old block comes out nothing quite fits with the replacement block or, if it does, it still needs to be replaced because you notice the wear and you might as well do it now whilst the engine is out, to save a further engine-out a little way down the line.

I recently witnessed a repower from Volvo AQ151 to Mercruiser 3.0 MPI with catalyst and power steering. Once the old lump was out the transom showed signs of rot and had to be rebuilt and finished with new grp and gelcoat. Ended fine but wasn't a cheap addition to the project :ambivalence:.

 

[QBhoy]

As mentioned...the gear ratios in the leg are different, between the 3.0 and 4.3. The mpi has more power than the carb 4.3, so might even be different again. You would be lucky if you got away with just a prop change....might not be too good for the drive at that.

 

[Bigplumbs]

I would have thought that would be the cheaper option too..

Only problem is it is a bit like looking for Rocking Horse Do Do and Hens Teeth not easy to find

Dennis

 

[wipe_out]

Only problem is it is a bit like looking for Rocking Horse Do Do and Hens Teeth not easy to find

Dennis

That I understand..

I guess you have to evaluate the reason you want the bigger engine (more power/more speed/because it's cool) and then decide if it's worth the cost and effort vs just using the boat you have as it is and maybe buying a bigger/faster boat when the one you have is no longer the one you want..

 

[Bigplumbs]

That I understand..

I guess you have to evaluate the reason you want the bigger engine (more power/more speed/because it's cool) and then decide if it's worth the cost and effort vs just using the boat you have as it is and maybe buying a bigger/faster boat when the one you have is no longer the one you want..

I think those comments are very wise

Dennis