Operation and maintenance manual

SEBU8601-01 69
Operation Section
Cold Weather Operation
In cold weather
, check the coolant often for the
correct glycol concentration in order to ensure
adequate freeze protection.
Engine Block Heaters
Engine block
heaters (if equipped) heat the
engine jacket water that surrounds the combustion
chambers. This heat provides the following functions:
•
Startability is improved.
•
Warm up time
is reduced.
An electric block heater can be activated once the
engine is s
topped. A block heater can be 110 V dc or
240 V dc. The output can be 750/1000W. Consult
your Perkins dealer or your Perkins distributor for
more infor
mation.
Idling th
e Engine
When idling after the engine is started in cold
weather,
increase the engine rpm from 1000 to 1200
rpm. This idling will warm up the engine more quickly.
Maintaining a n elevated low idle speed for extended
periods
will be easier with the installation of a hand
throttle. The engine should not be “raced” in order to
speed up the warm-up process.
While the engine is idling, the application of a light
load (parasitic load) will assist in achieving the
minimu
m operating temperature. The minimum
operating temperature is 80° C (176° F).
Recomm endations for Coolant
Warm U
p
W arm up an engine that has cooled below normal
opera
ting temperatures due to inactivity. This warn
-up should be performed before the engine is
returned to full operation. During operation in very
cold
temperature conditions, damage to engine
valve mechanisms can result from engine operation
for short intervals. This damage can happen if the
engi
ne is started and the engine is stopped many
times without being operated in order to warm up
completely.
When the engine is operated below normal operating
temperatures, fuel and oil are not completely burned
in t
he combustion chamber. This fuel and oil causes
soft carbon deposits to form on the valve stems.
Generally, the deposits do not cause problems and
th
e deposits are burned off during operation at
normal engine operating temperatures.
When starting a
nd stopping an engine many
times without being operated in order to warm up
completely, the carbon deposits become thicker.
This starting
and stopping can cause the following
problems:
•
Free operati
on of the valves is prevented.
•
Valves become stuck.
•
Pushrods may become bent.
•
Other damag
e to valve train components can
result.
For this re
ason, when the engine is started,
the engine must be operated until the coolant
temperature is 80° C (176° F) minimum. Carbon
deposits o
n the valve stems will be kept at a minimum
and the free operation of the valves and the valve
components will be maintained.
The engine must be thoroughly warmed in order
to keep other engine parts in better condition. The
service l
ife of the engine will be generally extended.
Lubrication will be improved. There will be less acid
and less sludge in the oil. This condition will provide
longer s
ervice life for the engine bearings, the piston
rings, and other parts. However, limit unnecessary
idle time to10 minutes in order to reduce wear and
unneces
sary fuel consumption.
The Water Temp erature Regulator and
Insula
ted Heater Lines
The engine is equipped with a water temperature
regul
ator. When the engine coolant is below the
correct operating temperature, jacket water circulates
through the engine cylinder block and into the
engin
e cylinder head. The coolant then returns to the
cylinder block via an internal passage that bypasses
the valve of the coolant temperature regulator. This
ensu
res that coolant flows around the engine under
cold operating conditions. The water temperature
regulator begins to open when the engine jacket
wate
r has reached the correct minimum operating
temperature. As the jacket water coolant temperature
rises above the minimum operating temperature, the
wat
er temperature regulator opens further allowing
more coolant through the radiator to dissipate excess
heat.
The progressive opening of the water temperature
regulator operates the progressive closing of the
by
pass passage between the cylinder block and
head. This action ensures maximum coolant flow
to the radiator in order to achieve maximum heat
di
ssipation.