Traditionally, RVs have used wooden fixed pitch propellers. These are available direct from the manufacturer (a partial list is included in the Builders Manual) and have given excellent service. They are light, reasonably priced and smooth running. They also offer a measure of protection to the engine in the unlikely event of a prop strike: the prop shatters, but usually leaves the much more expensive engine unhurt. However, wooden propellers require constant attention to bolt torque and blade condition. They are prone to damage if flown in rain or operated on gravel.
To overcome the drawbacks of wood props, many builders have expressed an interest in fixed pitch metal propellers. Previously, Van's recommended against this, because there was no metal prop that could be repitched to handle the speed of an RV without exceeding the twist or pitch limits established by the manufacturer. Several accidents in high speed homebuilts have been traced to propeller blade failure in repitched props. The Sensenich Propeller Company has designed a fixed-pitch metal prop specially for high-speed homebuilts like the RV. On the plus side, this prop is quite efficient and very low maintenance. On the debit side, it is more expensive than a wood prop.
An increasing number of airplanes are being equipped with constant-speed units. With a constant-speed, the engine can develop full power on take-off and climb, increasing performance considerably. Cruise speed increases only slightly, but fuel efficiency is improved. There is no doubt that a constant-speed prop is more efficient and flexible than a fixed pitch, but this is balanced by the dramatically greater expense and complexity. Choosing a propeller is a series of compromises. The 'correct' prop depends on many factors.
Van's does not supply wood propellers. We prefer to let the builder order direct from the manufacturer. We do supply the mounting hardware necessary for a typical wood prop. Before 1994, all fixed pitch installations used a 4" spool type prop extension between the crankshaft and the prop, while the constant-speed prop had an integral 2 1/4" extension. In 1994 we began offering a 2 1/4" cylindrical extension for fixed pitch props and standardized on the shorter cowl, which is still known as the 'constant-speed' cowl, even though both constant-speed or fixed pitch props can now be installed. We still stock bolts for the 4" extension for older kits and repairs. Study the charts and drawings so you are sure you are ordering the correct parts for your aircraft. Along with a propeller extension, a wood prop requires a crush plate on the forward face, between the bolt heads and the prop. Crush plates differ, depending on whether you are using the spool or cylindrical extension.