The oil filter will extend engine life. When these engines were designed filters were in their infancy and were considered a luxury. Non-detergent oils were used, which allow the grit to settle in the bottom of the oil pan, where some of it stayed. The detergent keeps the grit in suspension so the filter will trap it. The filter is worth every penny spent by reducing wear on the engine. The later 216 and the early 235 was equipped for a bypass filter, which was an accessory or added on as an aftermarket item. They only filtered about 10% of the oil that was pumped through the engine, but did help a lot in getting rid of the grit.
The modification is rather simple and is best done when rebuilding an engine so that metal fragments can be washed out before running the engine.
