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Figure #15
Note: Intake Air Shutoff Valve – Engine may
include an intake air shutoff valve as an optional
feature that is activated by an overspeed event
and provides a positive shutoff of combustion air
to the engine. The optional air intake shutoff
valve has not been evaluated by UL as part of a
UL Listed fire pump driver.
3.2.4
Crankcase Ventilation
3.2.4.1 ZF6H – Open Crankcase Ventilation
(Refer to
Figure #16
)
Vapors which may form within the engine are
removed from the crankcase and gear train
compartment by a continuous, pressurized ventilation
system.
A slight pressure is maintained within the engine
crankcase compartment. Vapors expelled through a
vent pipe attached to the rocker cover breather
element. Ref.
Figure
#16.
Figure # 16
Engine
Model
Open Crankcase
Ventilation
ZE4H
Standard
ZF6H – all models
Standard
3.2.5 Exhaust System
Excessive back pressures to the engine exhaust can
considerably reduce both engine performance and
life. It is therefore important that exhaust systems
should be the proper diameter and be as short as
possible within the minimum amount of bends. Refer
to Installation & Operating Data (see Page 5) for
exhaust data. Also refer to table below for maximum
exhaust restrictions.
Base engine
Exhaust backpressure
(inches of water)
ZE4H
15
ZF6H
15