3 to 4 blade prop.
 

Gonna pick up a 4 blade prop to try. Mercruiser 454. Bravo one. My question is when I switch to a 4 blade, do I go up in pitch or down or stay the same? Currently have a 23p 3 blade.

you go down when going to a 4 blade, there is more to consider than just pitch.

The short answer is go down in pitch. IF I was you, and doing the swap you are suggesting I would try a Bravo 1 22" 4 blade. On the other hand if you were switching to a Rev 4 I might go down to 21" due to the massive blade area of the Rev 4. As Phragle suggested there is more to it than just pitch. You would be erring on the safe side by going down in pitch when adding blades.

Awesome
 

Thanks for the advice

90MirageTrovare,

As stated, there is more going on than just pitch.

On our previous boat, a Rinker 236 Sport Cuddy (about 425HP), it had a 22P Bravo (4B) that had been reworked to 21P. My dad noticed from his boat that we were riding very wet (bow down). We swapped props with a local repair guy we often used, for a 23P 3B of unknown make he had hanging on the wall. We picked up 11MPH, and the boat launched and planed off MUCH quicker (opposite to conventional wisdom). The significant change was in the lift of the two props. Considerably less lift in the 3B allowed the hull to ride much dryer, and we got a lot more efficiency out of the water the prop was moving.

Something else to chew on.

Thanks. Brad.
(937)545-8991

Not trying to derail, just learn, a Bravo 1 is 15 1/4 inch and a Revolution 4 is 14 5/8 inch but your saying the Revolution still has more blade area?

If your WOT rpms were in the correct range, then drop 1" of pitch going from a 3 to 4 blade

Yes, WAY more blade area. Diameter can be deceiving. The Bravo 1 blades profile tapers out very quickly from hub to tip. The Rev 4 has not only more root cord but a larger profile near the tip. Look at one blade on each and map out the surface area.

right on, thanks for the info. Yeah my dads 23’ mirage rides super dry with a 23p 4 blade.