propellersboat parts

Are all props created equal?

  • Propellers come in all shapes and sizes. Material used, number of blades, hub type, pitch and diameter. Every boat, engine and propeller combination perform differently. There are a few constants that generally you need to obtain. The first is the full throttle rpm achieved with the chosen propeller. Your engine must reach its designed rpm range or it is not going to be the right choice. If rpm is to high you will need an increase in pitch or diameter or combination of both to lower the rpm into its designed operating range. If is too low then you need a smaller diameter or pitch combination to raise rpm's. Once you are operating within the engines rpm range you next want to look at overall performance of the boat with that propeller. Does it plane fast enough. Does it perform at the cruising rpm range you prefer or does it need to go at rpm range higher to keep on plane.
    There are many designs of propellers that serve specific purposes. If you just want to go fast then a propeller of a higher pitch can be used if it incorporates ventalation into the blade surface to allow slippage and rpm increases and speed increases. If loads are very high and the boat requires a higher than desired cruising rpm to maintain plane then an increase in number of blades can help. Everytime you change blade configurations you have to start all over again to find that sweet spot where rpms are where you feel comfortable and speed is adequate to maintain plane.
    For high performance enthusiasts you have new conventions to determine. These propellers come in many different designs and are in two categories. Stern lift or Bow lift. Stern lift propellers are designed to lift the transom out of the water while bow lifting props lift the bow. This is a choice which is hull dependant. a tunnel hull does not do well with bow lifting and v bottoms without bow lift built into their design do not like stern lift.
    Lastly we look at surface riding propellers which are generally left to racing hulls as to obtain higher top end you lose planing and weight capabilities. In racing on closed course the objective is to get the hull airborne as fast as possible and choose the largest pitch you can to get from point a to point b in the shortest amount of time and at the highest speed for the staitaway length.
    For standard operation OEM propellers always work best. Mercury makes the best propellers for use on many engines. Suzuki and Honda generally have to use their own props and just are what they are.
  • Follow us on facebook to ask us your Questions
  • Mobile Marine Services in South Florida on Facebook

Our Other Services:

  • High quality marine repairs on all major brands of outboards, sterndrives and inboards.
  • Custom rigging and accessory installation.
  • Contract yacht maintenance.
  • Brokerage service
  • Pre-Owned vessel sales
  • Vessel locator service.

Cool and useful boating information

Copyright 2008 - 2018 all rights reserved |  Designed and maintained by: Donald Quina for MarineSurveysPlus | Sitemap
    Whether it is for routine maintenance or major repairs, you depend on us to get you out on the water and most importantly, to bring you safely back home. Our relationship is a special one, which is built upon trust and experience. We pride ourselves in the services we provide our customers and openly invite you to join us.