Propping a new Merc 4.3/MPI?

[andy1canada]

Howdy!

Thought I'd cast a line for opinions/ideas on which prop I should run with or try out on my 19/ft Zeta cuddy.

The new engine is in and she's pretty much ready for sea-trials. I'm so-o-o stoked I can hardly wait!

She originally had a 305/Chevy Mercruiser but that's just been replaced with a new Merc 4.3/MPI/Alpha/220-hp set up. She weighs in at about 3000/lbs empty and has a deep 'V' hull.

For the time being I'm going to try out the original 4-blade alum that was pushing the old 305'. I'll run that prop during break-in and then see what the WOT numbers are after that. I don't have the current props dia/pitch numbers handy but could get them soon enough.

I want to swing a good SS/prop that will do double duty as a decent cruising/economy wheel as well as be able to yank the odd skier out of the hole. Naturally, I also would like to be able to realize the 50-mph top-end this mill should be capable of.

If this old alum/4-blade doesn't cut it, any suggestions on which dia/pitch I should try next?

Thanks all for your time and trouble!

Cheers,
Terry

 

[tommays]

Re: Propping a new Merc 4.3/MPI?

A current boat with that motor would have a 21" 3 blade as a WAG some lighter go-fast ones like a Stingray might go to a 23"



Tommays

 

[Bondo]

Re: Propping a new Merc 4.3/MPI?

Ayuh,.........

My WAGuess is;

That 4.3l is about the Same HP as the old 305 was,+ the Same Props are going to yield the Same #s..............