The Flex-Hone® for Volkswagen Jetta Engines

The Volkswagen Jetta is a compact car that succeeded the popular VW Beetle and appealed to drivers who prefer small family sedans with more conventional styles. Introduced in 1979, the Mark 1 Jetta featured a trunk instead of a hatchback and was marketed as an upscale alternative to the sturdy Gulf. Today, the Volkswagen Jetta is a sixth-generation vehicle that’s designed to compete with the Honda Civic and the Toyota Corolla. For Jetta enthusiasts, however, older versions of the German-engineered automobile are worth restoring, even when the engine needs rebuilding.     

Ball Hones for Engine Cylinders
For mechanic named Aarchaic at Street Racing Forums, restoring a 1991 Mark 2 Jetta meant buying a used 2.0L Volkswagen ADY engine and “making a shopping list” for auto parts such as bearings, a pulley, and a crank bolt. The South African hobbyist also needed cleaners to remove oil and grease from the engine block, and a flexible “ball hone” for restoring all four cylinders. Although Aarchaic didn’t mention our Flex-Hone® tool by name, we can tell from the picture (above) that the engine hone he chose is one of ours. Versatile and easy-to-use, the Flex-Hone® mounts in an electric hand drill and is a favorite of automotive hobbyists whose workshop is their garage.

Cylinder Hones and Cylinder Restoration
Built with a stiff metal stem and abrasive nylon filaments, the Flex-Hone® features abrasive globules for a soft cutting action. With their independent suspension, these “dingleberries” ensure that our cylinder hone is self-centering, self-aligning to the bore, and self-compensating for wear. The crosshatch pattern that the Flex-Hone® produces also appeals to engine builders. Unlike honing stones or other rigid hones, BRM’s flexible honing tool produces a uniform pattern of peaks and valleys for optimum oil retention. If a crosshatch angle is too steep, piston rings won’t seat properly. If a crosshatch angle is too shallow, engine problems can include increased ring break-in time and extreme piston ring wear.  

Engine Hones and Surface Finishing
Unlike other engine hones, the Flex-Hone®  tool is designed for surface finishing – not material removal. Its low-temperature abrading process exposes the undisturbed base metal structure to produce a long-wearing surface on engine cylinder walls. Flex-Hone® users may call our brush  tool by other names (including ball hone), but the results speak for themselves. As Aarchaic explained to his fellow Jetta enthusiasts at Street Racing Forums, “the ball hone did an exceptional job” on all four cylinders of his rebuilt Volkswagen engine.