The oil pump is normally situated in the lower part of an engine close to the oil sump to facilitate pumping the oil that has accumulated there. The water pump is also normally located in the lower part of an engine because both pumps share the shaft that drives them.
In this engine, so as to obtain rotational driving force from the camshaft, the water pump is located on the left-hand side of the cylinder head in the upper part of the engine. This layout has made it possible to considerably shorten and reduce the water piping, resulting in a water hose which is one-third shorter in overall length than that used in a conventional layout. Accordingly, cooling water volume has been reduced, contributing to both weight reduction and more elegant piping.
Thanks to the emphasis placed by the engine development concept on low and middle, instead of high, rpm, it has been possible to circulate water with a water pump that is optimally driven by the rotating speed of the camshaft, which has in turn resulted in effective streamlining.