Michigan Wheel Michigan Match #031080 Aluminum Boat Propeller 4 blade

[Starcraft5834]

I have a 4 blade Solas 14.5x 15pitch on my Alpha One 3.0 GM 140. in line 4. getting 32 gps at 4800 rpm. I just bought a Michigan Wheel 15x16pitch. I like the sound of my motor running just below WOT,, to around 4500-4600 rpm,, my plan is to use Solas as back up and hope to bring down my WOT and increase top speed just a speck.....my plan sound right? that 16p will bring down my RPM a little?

 

[steelespike]

Re: Michigan Wheel Michigan Match #031080 Aluminum Boat Propeller 4 blade

What size and year boat. Actually increasing your pitch will be making the motor work harder. Your present slip is about 6%
at 4800 rpm assuming 2.00 gear ratio. Unusually low. If you go to a 16" pitch and we assume about a 200 rpm loss of rpm
you may also have more slip from the higher pitch so speed will probably be a wash.
Is the boat unusually heavy or large? Is the 16 a 4 blade?
Increasing pitch will likely slow hole shot,may make the boat harder to keep on plane at reduced throttle.

 

[Starcraft5834]

Re: Michigan Wheel Michigan Match #031080 Aluminum Boat Propeller 4 blade

1987 Imperialvc200 cuddy.. 2400lb listed dry weight... 20ft.. yes 16 is a 4 blade.... the current prop is good, I was finding at WOT, RPM's were not over reving.. just a speck more than I want. I like it about 4500...... the proposed blade is 15 inches,, about 1/4 longer than current prop. Im running with a flat anode... there's about 1 inch of room now, so I wont have a problem there... am thinking this might get me around the same numbers with a slightly less rpm at WOT,, that's really what I want.. will give it a go and see if hole shot is affected. I can tell you before I put on the 4 blade,, the 3 blade just did not have enough guts to get me on top of the water quick, now I'm up in less than 5 seconds,, with a load of people inside too....

 

[steelespike]

Re: Michigan Wheel Michigan Match #031080 Aluminum Boat Propeller 4 blade

I say if you want to try it you gotta try it.
But I don't understand why you just don't throttle back to 4500.
Keep in mind all marine engines are working very hard, kind of like a car going up a never ending hill pulling a trailer.
When you force it to run at a prop induced lower rpm it is kind of like putting the car into over drive on that never ending hill.
Let us know how it works out.

 

[Starcraft5834]

Re: Michigan Wheel Michigan Match #031080 Aluminum Boat Propeller 4 blade

Will do.........was thinking with my engine running at WOT around 4800 or a bit over with current 15p prop, I could get it down to 4500-4600 and maybe get a mph or two more top end speed with the 16p 4 blade........

 

[Georgesalmon]

Re: Michigan Wheel Michigan Match #031080 Aluminum Boat Propeller 4 blade

You really want the motor to be able to run in its recommended WOT range at your average or light load. Then go ahead and run at whatever rpm you want to. Its not a good idea to get a prop that will run the motor at a lower or higher WOT RPM then the manufacturer states. Changing RPM after you do that is what the throttle is for. JMHO

 

[Starcraft5834]

Re: Michigan Wheel Michigan Match #031080 Aluminum Boat Propeller 4 blade

thanks all,, will keep eye on it.. was thinking the 16p prop will get me right where I want to be, #'s wise........the 15p now I think is not quite enough prop and I may benefit from the 16.. if I note issues, will put the 15 back on and keep 16 as spare

 

[Starcraft5834]

Re: Michigan Wheel Michigan Match #031080 Aluminum Boat Propeller 4 blade

update... got the Michigan Match 4 blade,, installed it and spun it around, it "wobbles" pretty bad. yes, it's installed right..I put the solas 4 blade 14.75 x15 back on, spun it,, just fine... wow,, was not expecting that,, what horrible quality control,, back to the retailer it goes...think i might better stick with Solas....

 

[Starcraft5834]

Re: Michigan Wheel Michigan Match #031080 Aluminum Boat Propeller 4 blade

Wanted to update results with the Michigan Vortex 15x16 4 blade...out on lake yesterday, hole shot good, got 33mph at 4500 rpm.. had 14.75x15p before, rpm's went down about 200, speed up 1. bout where I want to be,, if Im gonna tube, will put the 15P back on..