#### BillD

##### Admiral

- Joined
- Sep 1, 2011

- Posts
- 8,089

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- Boat Make
- 27 H&H with Cummins QSB 5.9 480 power

Maybe no perfect answer to my question.

Assume two identical DE boats. Let's assume the hull is the builder's 33 footer.

The prop aperture of the hull can accommodate up to a 28" prop with standard accepted clearance.

Each is the same weight, 14,000 lbs.

Each has the same engine, 480 hp, rated 3300

2.5:1 gear with a 2" prop shaft

Cruising rpms for recreational use 2600 rpm.

Prop calculator suggests a 4 blade 26X31 prop or the equivalent

4 blade 28X28

rule of thumb........assume 1" of diameter equals 2.5" of pitch.

rule of thumb the 26X31 is the equivalent of 28X28

solid cruise speed is of most importance, not wot speed.

I've heard from builders and long time DE owners that a 4 blade square prop is "best" for a keel boat.

I've heard from builders and long time DE owners that the square prop being "best" for a keel boat is a myth.

Which prop would you choose?

FWIW,

Bill D