Now, with this information, you can easily calculate a rough ratio by taking the input speed divided by the output speed, or 1800 divided by 1.667, which gives you an approximate number of 1080. This is where it gets a little tricky, and where you either need to know the gearbox, or ...
The best bet is a compromise between these extremes, a prop size that puts the engine in the sweet spot of its RPM range for everyday use. Conclusion When selecting a boat propeller, you should go for a higher pitch if you care about boat speed. However, a lower pitch will be the be...