Specyfikacje Śruby 14" × 11"
Współczynnik skoku 0.79: teoretyczna prędkość przy 1 000–4 000 obr/min
Overview
A 14-inch diameter by 11-inch pitch propeller produces a pitch-to-diameter ratio of 0.79, which falls into the balanced cruising bracket. The diameter sets the disc area that converts engine torque into thrust, while the pitch sets the theoretical distance the propeller advances per revolution. At 2,500 RPM through a 1.5:1 gearbox this combination posts a theoretical no-slip speed of 15.1 knots; at the 4,000 RPM upper trace the same prop reaches 24.1 knots, with real-world slip pulling those numbers down by 10–20 percent depending on hull loading and bottom condition.
Specyfikacja śruby napędowej
| Średnica | 14" |
|---|---|
| Skok | 11" |
| Współczynnik skoku | 0.79 |
Prędkość teoretyczna wg obrotów
| obr/min | Prędkość (poślizg 0%) | Prędkość (poślizg 15%) |
|---|---|---|
| 1,000 | 6.0 | 5.1 |
| 1,500 | 9.1 | 7.7 |
| 2,000 | 12.1 | 10.3 |
| 2,500 | 15.1 | 12.8 |
| 3,000 | 18.1 | 15.4 |
| 3,500 | 21.1 | 18.0 |
| 4,000 | 24.1 | 20.5 |
Typical applications
The 14"×11" size is most commonly fitted to family runabouts, walkarounds, and 75–150 hp center consoles, where the balanced cruising pitch profile matches the planing performance window. Boats inside this class generally cruise between 15.1 and 24.1 knots on the speed chart above. Mid-range RPM windows are where most family runabouts and cruising boats spend their hours. If your boat tops out far below the 24.1-knot theoretical figure, the propeller is over-pitched for your loaded weight and slip will climb toward the 15-percent column; if you over-rev past the engine's WOT range, the propeller is under-pitched and you should step up one or two inches of pitch.
Compared with adjacent sizes
Holding diameter at 14" and dropping pitch by two inches yields a lower top speed but quicker hole-shot and better load-carrying behaviour, which is why 14"×9" propellers are popular for heavy or family-loaded boats. Raising pitch by two inches to 14"×13" trades acceleration for roughly 2.7 knots of additional theoretical speed at the same RPM. Holding pitch at 11" and changing diameter shifts thrust area: a 13"×11" prop spins up easier on small engines, while 15"×11" needs a stiffer driveline but bites harder under load.
Sizing notes and assumptions
The speed table assumes a 1.5:1 gear reduction and the standard propulsion identity (pitch × RPM) ÷ (gear ratio × 1,215.2) to convert inches-per-minute into knots. Slip estimates of 0 percent (theoretical) and 15 percent (realistic cruising) bracket most clean-bottom planing hulls; expect higher slip on displacement vessels, fouled bottoms, or when towing. Always confirm propeller choice against the engine manufacturer's recommended WOT RPM window — landing inside the band protects the powerhead from lugging or over-revving and is the single biggest factor in long-term engine life.