How to Save 24 Pounds – and Look Great Doing It!


Whirlwind Series 300 - three blade prop RV-8Our loyal RV-8, the Valkyrie, is rapidly approaching the 2000 hour mark on the Hobbs, and all of that time, she has been flying with the old reliable Hartzell Blended Airfoil propeller that came out shortly before she was built. Over the years, the “Val” has seen a lot of different equipment come and go – various generations of EFISs and IFR navigators, cameras, HUDs, and lots of portable navigation boxes. But all that time, she has soldiered on with the Hartzell.

Today, she got a facelift, courtesy of Jim Rust, Reno Racer and owner/ chief engineer of Whirlwind Propellers. Jim has taken all his years of experience in propeller design and come up with the new Series 300 – a three blade prop for the four cylinder Lycomings that weighs in at just 36 pounds – spinner included! Building on his previous two and three blade versions (we have been flying the three-blade model 151 on our RV-3 for over 750 hours), he has designed new blades that promise superior performance – and darn if they don’t look great!

The installation was straightforward – unbolt the old prop, bolt on the new one, safety wire, and attach the spinner (which was completely pre-fit…no cutting or other work required). As is the case with most constant speeds, the safety wiring was the biggest portion of the job. After that, we ran things up, cycled the prop to make sure it worked properly with our governor, and then ran a dynamic balancing on the prop/engine combination using our Dynavibe. We quit tweaking at 0.03 inches per second vibration, and it feels smooth as glass. Then the afternoon thunderstorms rolled over the mountains, spewing lightning, starting a few fires, and bringing visibilities down to a mile as smoke blew in from California fires – so first flight has to wait.

We’ve collected recent baseline data with the old prop, and look forward to bringing you test results on the new one soon!

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Paul Dye
Paul Dye, KITPLANES® Editor at Large, retired as a Lead Flight Director for NASA’s Human Space Flight program, with 40 years of aerospace experience on everything from Cubs to the Space Shuttle. An avid homebuilder, he began flying and working on airplanes as a teen and has experience with a wide range of construction techniques and materials. He flies an RV-8 and SubSonex jet that he built, an RV-3 that he built with his pilot wife, as well as a Dream Tundra and an electric Xenos motorglider they completed. Currently, they are building an F1 Rocket. A commercially licensed pilot, he has logged over 6000 hours in many different types of aircraft and is an A&P, FAA DAR, EAA Tech Counselor and Flight Advisor; he was formerly a member of the Homebuilder’s Council. He consults and collaborates in aerospace operations and flight-testing projects across the country.


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