Tractor and Drives
Figure 1. Instrument Panel - (Protective Cover In Unlocked Position)
The paver engine is a GMC Model 3-53N Diesel with 4 Valve Head, Specification No. 5033-7201, Rating: 74 HP @
2000 RPM, Compression Ratio: 21 to 1, Injectors: N-45, Governor Setting: 2100 RPM-Full Load, 2200 RPM Max. Hi Idle,
500 RPM Lo Idle, with selected custom features. This engine complete with custom features is supplied by Hicklin GM
Diesel Corporation, Des Moines, Iowa per Iowa Manufacturing Company Specification No. 45924-008-02.
The GM 3-53 diesel engine is equipped with a speed governor which should be set at 2000 RPM when the engine
is at full throttle. Important! Engine speed should not vary more than 3% regardless of load.
Engine speed is directly proportional to the output of the Frequency Meter (Figure I above) which indicates the
speed of the 120 VAC belt driven generator unit (Section IV). At the 2000 RPM engine speed, the generator will produce
a 61 cycle reading on the Frequency Meter. When the meter is at 61 cycles the engine speed (at full throttle and no
load) may be considered correct.
All paver instruments are mounted in the lockable enclosure on top of the engine housing. (Figure 1) A description
of the instrument functions follows.
A. Oil Pressure Gauge: Indicates engine oil pressure (Refer to engine manufacturers manual for details).
B. Engine Fuel Level Gauge: Indicates level of Diesel fuel in the 33 gallon supply tank. Gauge markings are in
quarter-tank increments. Gauge sensor in tank is shown in Figure 3, page 18.
C. Water Temperature: Indicates temperature of coolant flowing through engine block and radiator.
D. Ammeter: Verifies proper function of the 12 VDC battery charging circuit. Power is supplied by the belt driven
generator unit on the side of the engine (See Section IV). At full throttle the ammeter reading should be positive,
indicating a charging of the battery.
E. Voltmeter: Indicates voltage output of belt driven AC generator unit which as 120 VAC rating. (See Section IV).
With Engine at full throttle voltage must not be less than 120 V. nor more than 135 V.
F. Frequency Meter: Indicates speed (in cycles
per second) of 120 VAC generator. When the engine is at full throttle the meter should show no less than
59 CPS nor more than 61 CPS.
G. Hour-tachometer: Indicates engine speed on dial and registers the number of engine operating hours
accumulated (on counter) since paver left factory. This combination tachometer and time recording instrument operates
whenever oil pressure developed by engine operation closes a pressure switch. (See wiring diagram in Section IV).