This approval permits using Skytronics leads in the original W670 unshielded (rear) loom and gives a shielded harness that looks very much like the original unshielded harness and allows the use of radios.

By trimming the lower section from the engine baffles and replacing the aluminum with a rubberized baffle seal, it is now possible to retorque the cylinder base nuts without removing the baffles. Since the nuts need to be retorqued every 100 hours, a $6000 labor saving can be realized over the life of the engine and the baffle mod encourages regular cylinder base nut maintenance.

The original oil seals for the magneto drive gears were leather seals that retained moisture, caused corrosion on the gears, and hardened with age. A modern nitrile rubber seal is now approved that directly replaces the original leather seal.

This approval permits the use of the improved NAR6G carburetor as a direct replacement for the older NAR6D carburetor on all W670-6A and W670-6N engines.

Engine liquid locks have been the Achilles heel of the radial engine design. By installing automatic drains on both the #5 and #6 intake pipes, oil can no longer collect in these pipes and cause liquid lock but rather drains to the back of the cowling where it can be collected.

All reciprocating and rotating engine assemblies are balanced to within 4 grams of one another. This produces an exceptionally smooth running engine free from the vibration characteristics of engines assembled from unbalanced random parts.

Roller main bearings are now used in all Continental engine overhauls at Radial Engines, Ltd. These roller bearings give an added margin of safety to engine operation and are much more robust than the
original ball type main bearings.

After many years of scarcity, new pistons are again available for use in Radial Engines, Ltd. engine overhauls.