The cause of the excessive flows is an
oversized oil pump, with a theoretical output
of 26 litres/min per 1,000rpm and relatively
low volumetric efficiency at high engine
speeds, approximately 75 per cent giving anoutput of 86 litres/min at rated speed. There
are two options for solution, either reduce the
opening pressure on the relief valve or
redesign the oil pump with a reduced output.
Both options reduce the overall oil pressure in
the system with the additional benefit of
reduced hydrodynamic pumping losses.