MoTeC M84 - Manual (Page 24)

22 Installation MoTeC
Swirl Pot
The swirl pot (header tank) maintains a reserve of fuel to avoid fuel starvation
to the engine during cornering and acceleration. Fuel starvation can also
cause damage to the pressure pump as it relies on the fuel for cooling,
lubrication and speed limiting.
The swirl pot also forms a header tank for the pressure pump since the
pressure pump is not capable of lifting the fuel from the tank if the tank is
lower than the pump. Place the swirl pot at the same level, or higher than the
pressure pump.
Pressure Pump
The Pressure Pump is a high pressure pump that must be capable of
delivering the required amount of fuel at the correct pressure at full power.
It is very important that the pump is capable of maintaining the correct fuel
pressure at full power otherwise the engine could be damaged due to a lean
mixture.
A 600 hp engine requires a flow rate of approximately 250 lb/hr for petrol or
gasoline.
Notes
• The pressure pump must be lower than the outlet of the swirl pot.
• Prime the pump with fuel before use.
• The pump’s flow capability is dependant on the required pressure, the flow
capability of the pump will be less at higher pressures. A small pump will
maintain correct pressure at light load but will not maintain correct
pressure as the flow requirement increases.
• On boosted engines the pressure required from the pump increases with
boost pressure because the regulator maintains constant pressure above
manifold pressure.
• Avoid running the pump dry as this may destroy the pump.
Filters
The filters are necessary to ensure that the fuel pump is not damaged and to
ensure that the injectors do not become blocked.
• The strainer before the pressure pump is essential to prevent the pump
from seizing. A strainer is used because the pressure pump won’t suck
through a paper filter.