Minimum Planing Speed

[76Red18]

Does propeller pitch affect minimum planing speed?

[gofastsandman]

YES! Just back in from the first coat of Epifanes, but that`s another thread. I`ll start another one as that black magic is a hot topic.
GFS

[76Red18]

It's not the forward momentum that lifts the hull to the planing position? My thinking is that a lower pitch prop would get there faster but at the same mph as a higher pitch. I have a 17 and 19 but they are different props. the 17 is a bow lifter and no good on the boat. the 19 picks the stern up and will plane at 15 - 17 mph. If I wanted a lower planing speed a 17 with same characteristics as the 19 might do it then?

[Old'sCool]

A four blade will allow a lower planing speed.

[Kahuna]

RED,
I had a similar problem. To maintain a lower planing speed, I put one of those 'dolfins' on my outdrive. you have to be careful around the dock as if you contact something with it, you have more surface area working smaller cross section of the cavitation plate. The cavitation can be damaged. You will loose a knot of so on your top end, but when it gets sloppy, you can trip the drive down, slow your speed stick the bow right in it and it is much more comfortable. It was really needed with the old power. we will have to see how things go with the new power. just my experience.

[Bushwacker]

Fr. Frank will probably chime in here with a technically correct answer, but I believe rake of the prop has a lot to do with it. Before I repowered, my Seafari would plane nicely at 12-13 mph with an ancient (but light!) 115 Evinrude running a 13 3/4 x 15 SST prop. Of course it's better balanced than a CC because helm is further foward and weight of the cuddy up front. When I repowered with a much heavier motor and a bracket w/30" offset, it would not plane below about 3500 rpm/25 mph with a 14.25x17 3B SS prop; a 14.5x19" 3B SS prop was a little better at ~2600/17 mph. This was a huge issue for me because I often like to be able to cruise at min planning speed offshore when the seas kick up.

Currently running 2 different Michigan 4B props, both of which plane easily @ 12-13 mph: 14x18 Vortex (Al) for heavy load planes at about 2700, and a 14.125 x 20 Apollo for light loads and a little better mpg, planes at about 2000. You have to be careful with the 4B props; some bass boat designs are BOW lifting! If description says designed for heavy offshore boats, it's probably STERN lifting.

[Bushwacker]

Forgot to mention, I also have a Doelfin installed, on old motor as well as new one. For the low planning speeds, you generally have to trim motor all the way down and put the trim tabs down. On the 25" shaft new motor/bracket setup, engine trim seems to have much more effect on running angle than on the old 20" shaft motor hung on transom. Maybe there's some extra leverage involved with the 30" setback on the bracket!

[76Red18]

No fin but do have tabs which knock off about 5 mph. Not really concerned about top end but with fuel prices I've been takeing two passengers to help with the cost. I' d like to be able to plane easier and at a lower speed when it gets a little rough. The 19 is a michigan apollo and the 17 is a omc viper.

[76Red18]

Do es the fin in any way make the stern dig down during a hole shot. I fish the flats often and only have a couple of pot holes that are barely deep enough for me to get up on plane.