350 CC Modified Hydroplane 

This class includes several motors:  20 cubic inch (approximately 350 cubic centimeter) Hot Rods and Mercurys, and the Yamato 80.  The Yamato 80 is the same basic motor used in the 20 Super Stock Hydro class.  Racers can perform some modifications to the motor as along as they are specified by the rules of the sanctioning organization.  These modifications may include:

• using an expansion chamber exhaust system to increase combustion chamber pressure and improve scavenging efficiency (see photo).
• streamlining of the leading edge of the lower unit to reduce hydrodynamic drag (see photo).
• providing an alternate cooling water intake to increase cooling water flow (see photo).
• a shortened mid-section (the "tower") and replace the gravity feed fuel tank with a fuel pump and remote fuel tank located inside the boat to lower the center of mass (not pictured).

 Modified motors can also run four blade propellers (stock engines are limited to three blades).

Photos