TECH TIPS: 
Marine vs. Automotive Replacement Parts

Many boaters are unaware of the difference between an automotive and a marine engine and its respective accessories. The most notable differences include the exhaust systems, cooling systems, electrical systems and the fuel systems.

With the Cooling Systems, one of the major differences is found in the water-circulating pump. Unlike their automotive counterparts, a marine pump works in an open cooling system. This type of system is extremely corrosive to the pump so it must be altered for longevity. A marine pump has a special ceramic seal, stainless steel backing plate and a bronze impeller to resist corrosion. An automotive style pump, with its stamped steel impeller, would fail in a short time due to corrosion.

The Electrical Systems in marine applications are also specialized. In an automobile, any gasoline vapors that may escape, will evaporate or vent from the bottom of the engine compartment. A boat, with its sealed engine compartment, will let escaped gas vapors accumulate in the bilge or engine compartment. Therefore, any spark could literally cause a boat to explode. All electrical components in a boat are either completely sealed or specially vented to prevent such a catastrophe. This includes the starter, alternator and distributor. Although we’ve only briefly touched on some of the differences between automotive and marine applications, hopefully it will serve to remind us that there are differences and the reasons for these differences need to be shared with our customers.