Marinediesel 5L V8, Owner'S Manual, Page: 190 / 248

Owners Manual 188 Section 3 - Engine
FUEL SYSTEM TEMPERATURE AND PRESSURE
DROP
General Information
The power output of an engine can be limited by the amount of restriction in the boat’s
fuel supply system. The Marinediesel specifications for the boat’s fuel system
performance regarding fuel inlet are:
Specifications For Fuel System Performance
Maximum Fuel Inlet Temperature Maximum Fuel Pressure Drop
110 q F (44 q C)
1 psi / 6.9 kPa
Power output of an engine is directly related to the amount of fuel demanded. An engine
with more power output can cause a greater demand on a fuel system and therefore
cause a greater fuel pressure drop. The design of the fuel system should always take
into account the highest output engine offered in the boat. Doing this will help prevent
performance problems related to fuel supply.
Air temperature and the RVP (Reid Vapor Pressure) of the fuel also play an important
role in fuel system performance. Higher air temperature can cause higher fuel line
temperature. Overall design of the fuel system and fuel line routing should take into
account the highest air temperature to which the craft could be subjected. In some cases
it may be necessary to measure the RVP of the fuel. Special test equipment can be used
to determine the fuel’s RVP or check with a local regulatory agency.