Why doesn MerCruiser put them on their drives as standard equipment?
We at Simrek feel that MerCruiser makes the finest stern drives on the market, but consider this; once their drives leave the factory, they loose the control of how their drives are installed on all the various engines, hull designs of all the different boat manufacturers, along with all the different propeller styles and sizes. Plus their drives are subject to the boat owners driving habits (RPM, trim levels, time on plane, etc.) and after market performance up grades. In order to incorporate a cooling system into the stern drive they would have to make major changes to the castings that make up the upper portion of the drive. While some changes have been made to the internal components, the castings for both the Alpha and Bravo uppers have not changed since they were first introduced. Adding a cooling system would require a major redesign of multiple castings at a substantial cost. MerCruiser is also in the repair parts business. There is a term used by manufacturers called “planned
