But how important is this? Isn't each propeller of the same pitch the same? The answer is no. Not only are props of the same pitch different, but according to Prop Scan there can be a difference in each blade. These differences in manufacturing tolerances can cause a variety of prop problems including vibration, tip erosion, cavitation, general poor performance, and bad fuel economy. Add to that, a prop hit and you really have a headache. The imbalance of props can and will destroy struts, shafts, and in extreme cases the engine itself. Add twin engines to the equation, and you can have twice the problem.

At a recent show, the folks from Prop Scan used their software technology to demonstrate problems with a stock production prop. Not only did we find a difference in the pitch that was stamped on the prop, but also in each of the blades. When questioned if this was just a bad prop, they answered that some props are better than other but that most of new props they have measured have some variance. In many cases Prop Scan stated this manufacturing tolerance may not cause a problem, but there are exceptions.

The best way to explain these variances is to take a look at the tires on your car or truck. They are all round and they roll down the road, but each tire must be fine-tuned, it's called balancing. We all know how unpleasant an out of balance tire can be. It's an analogy but the same theory applies to propellers.

The Process

How does Prop Scan work? First the prop is mounted onto a fixture or table. The table includes a rotating beam with a precise optical sensor that includes a scribing wheel. As the blades are rotated, the sensor and the wheel record the deviations in the blade from the original design. Information on the design and specifications are loaded into the system's computer. Using information supplied by the skipper about the engine's required RPM and performance, the Prop Scan software converts this data into line and bar graphs. Using this data and the data supplied by the manufacturer and the skipper, the software gives the operator a visual indication of the current and the desired pitch across the arc of each blade.

Although this is a simplified explanation of the process, you can be assured that if there is a problem with your prop, Prop Scan will find it and enable the technician to correct it. After the computers find the deficiencies in your prop, the prop will have to be hammered into the proper surface configuration. This process is truly a marriage between old and new technology.

The man behind this remarkable technology is Australian, Terry Ryan. Terry has combined his years of knowledge of propeller design and their physical properties, with his knowledge of programming to develop the Prop Scan process and system. His developments became so well respected throughout the power boating community that the Royal Australian Navy took notice. One thing led to another and they are now using this technology and now the Canadian and USA Navies use the system.

If Its Good for the Navy. . .

Now that we know Uncle Sam uses the Prop Scan system, what about us recreational boaters? This technology is readily available to anyone since Mr. Ryan has set up training schools which train technicians to use the Prop Scan system. Throughout the US there are now 19 Prop Scan repair stations to service our needs. What can we expect from having our props inspected and massaged using the Prop Scan system? The benefits are remarkable and include less vibration, increased fuel savings, less wear and tear on shafts, struts and bearings, and in some cases a 50% increase in your vessel's speed.

We spoke with a number of skippers that have utilized this system and they all rave about the results. The most common comment is that they were not aware that the vessels could be so smooth, vibration free and the increase in speed was an unexpected benefit. All this from a man with a vision, critical knowledge, and a desire to make every prop as efficient as possible. Our hats are off to Mr. Ryan.

For more information on this remarkable process, contact:

Propeller Solutions, Inc.
(619) 688-1965
California Propeller
(805) 644-8282