How come inboard props are more flat and have wider fins than and outboat or sterndrive prop?
2007-02-16 12:32:34 · 6 answers · asked by guitar_playa101 2 in Cars & Transportation ➔ Boats & Boating
Inboards have a fixed prop-shaft angle as compared to stern-drives. On an inboard you can't take advantage of optimum prop angle so the blades are designed to make use of this unfortunate situation. They have near zero rake and large diameters, lots of blade area to compensate for the lack of angle adjustment. The hp and gear ratio, size of load, all determine just how, "flat and wide", the propeller has to be on an inboard.......Get it, no tilt and trim.
2007-02-17 00:24:02 · answer #1 · answered by Anonymous · 2⤊ 0⤋
A boat prop is designed, with three things in mind. Horse power, weight of boat and speed. The more pitch on a prop the futher it will move forward in one turn, it has more pulling power but less speed on top end and takes longer to get on plane. Engine R.P M will be slower in coming up, due to the load on engine. What job will the prop do? A tug boat has l;ots of horse power and has a very large diameter prop with lots of pitch, A tug boat is made for pulling. A speed boat will have a smaller diameter prop with less pitch. This is why props are different.
2007-02-16 12:58:26 · answer #2 · answered by Anonymous · 1⤊ 2⤋
Props are rated by pitch. The high the pitch to more power the flatter the pitch the make rpm's and speed. that Prop is pitched for speed over power. Props come in roughly two classes, speed props and power props. Depending on application depends on what pitch prop you want. i.e. if you are pulling skiers you want a power props. If you are just cruising you want a speed prop.
Since inboards are mostly speed boats used for cruising they mostly have the flatter speed props vs. the outboards and stern drives that are used to pull skiers.
2007-02-16 12:43:33 · answer #3 · answered by JUAN FRAN$$$ 7 · 3⤊ 3⤋
basically a prop is a gear, the same way your rear end on your car and your transmission have differnent teeth on the gears
2007-02-19 16:02:47 · answer #4 · answered by sevenout7 4 · 0⤊ 0⤋
Depends on size of boat and power of engine.
2007-02-16 15:54:53 · answer #5 · answered by Anonymous · 1⤊ 0⤋
Some are for speed and some are for power. They have different number of blades, different size, different direction of rotation.
2007-02-16 14:09:14 · answer #6 · answered by science teacher 7 · 0⤊ 1⤋