7/16" Bolts to Attach 4" Prop Extension to Engine Flange
Used to Mount 4" Spool Extension to Crank Flange on Older Kits With Long Cowl
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.
Bolt size determined by engine crankshaft. New O-320 engines from Van's use
Priced as a set of six bolts.