One of the most difficult tasks a technical writer faces, involves prop testing. There is the data collection and technical aspects to these types of evaluations, there is also a lot of opinion and seat-of-the-pants personal feelings interjected into the final assessment. What one tester may like relative to prop characteristics and performance, another may dislike. Prop technology is not an exact science and most props are a calculated compromise.

While I've dreaded testing props over the years, there have been some bright moments. A few years ago I was invited to test and evaluate props manufactured by Mach Performance. I jumped at the chance, not because I wanted to spend a blistering August day on the lake, but because I welcomed the chance to watch the guru of props, Gary Gilbrect, work his magic. Gilbrect, is considered genius when it comes to props and what makes them work. His ability to read a prop and then make the necessary changes is uncanny and has been developed over many years of racing. With a cabinet full of trophies, many from wins on the International Formula One circuit in the company of the legendary K. Kiekhaefer, Reggie Fountain, and Bill Seabolt, he has certainly honed his skills.

At one point during that testing session one set of props was just not performing correctly. The port engine was turning 200 rpm higher than the starboard engine. When we reached the launch ramp Gary quickly removed the prop and borrowed a ballpeen hammer. He proceeded to work his magic on the cup of that prop, on no less than a trailer ball out in the parking lot. After 20 minutes of tapping and lots of eyeballing we were back on the water and much to my amazement the prop was right on. His years of experience had saved the day. Everyone in attendance was in awe and it was then that this guy became my hero.

Out of the Dark Ages

People like Gary are few and far between, but the mystery and dark science of props has emerged into the sunlight and is accessible to all of us thanks to computers. Over the last year I have watched and had demonstrated to me a new prop evaluation technology from Prop Scan.

Prop Scan is the most advanced technology used to scan each blade of your prop. With the latest software and some pretty sophisticated hardware they can scan a prop to make certain that each blade is equal to each other, not only in pitch but also from the root to the tip.