This document provides information on a 4.5L naturally aspirated engine from Weichai America Corp. including its specifications and performance ratings. The engine features a cast iron block and cylinder heads with wet cylinder liners. It has a proven electronic control module and meets J1939 interface standards. Power ratings of 50kW at 1800rpm are listed for both natural gas and propane fuels. Charts show the engine's fuel consumption curves at 1800rpm and 1500rpm speeds.

1. Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com

2. Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com

3. FEATURES
Engine & Block
• Cast Iron Block
• One-piece forged crankshaft
• Separate cast iron cylinder heads and wet cylinder liners
• Forged Connecting Rod
Cooling System
• Radiator and hoses supplied separately
• Thermostatically-controlled system with belt driven
waterpump and Pusher/Puller fan
Lubrication System
• Flat bottom high capacity oil pan (16 L)
• Cartridge oil filter
• High capacity gear driven lube oil pump
45kWe @1800rpm
Engine Control System
• Proven ECM, Fuel System and Engine Control
• Engine Protection
• CANBUS J1939 Standard Interface
• Telematics Compatibility
Air Intake & Exhaust System
• Rear Mounted, Replaceable Dry Air Cleaner
• Air Cleaner Restriction Indicator
Electrical System
• 12V electric starter motors
• Optional low voltage battery charging alternator
FLywheel & Housing
• SAE 1/SAE 3 flywheel housing and 11.5/10”
flywheel
4.5L NA POWER GEN
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com

4. 1
2
3
4
5
6
7
200
250
300
350
400
450
500
550
600
650
700
750
800
850
4 8 12 16 20 24 28 32 36 40 44 48 52
Total
Fuel
(gal/h
)
BSFC(g/kW.h)
Power (kW)
0
2
4
6
8
10
12
14
16
18
200
250
300
350
400
450
500
550
600
650
700
4.6 11.5 13.7 22.7 34.2 38.8 43.9
Power (kW)
Total
Fuel(m³/h)
BSFC(g/kW.h)
1
2
3
4
5
6
7
8
9
10
230
280
330
380
430
480
530
580
630
680
4 8 12 16 20 24 28 32 36 40 44 48
Total
Fuel(galloon/h)
BSFC(g/kW.h)
Power (kW)
Rating Fuel
60HZ (1800RPM) 50HZ (1500RPM)
kWm kWe kWm kWe
COP
NG 50 45 45 41
PG 50 45 47 43
Model Number
Bore & Stroke
Displacement
Cylinders
Governor Method
Fuel Type
Dry Weight
WP04GNA
4.13 in x 5.12 in (105 mm x 130 mm)
274 cid (4,500 cc)
4
9.75:1
ECM
Natural Gas / Propane
NA
1,102 lb (500 kg)
POWER RATINGS
56.1 in / 1,426 mm
43.2 in
1,098 mm
31.9 in / 811 mm
Weichai reserves the right to interpret
products and specifications, All data is
subject to change without notice.
Weichai America Corp.
3100 Golf Road Rolling Meadows, IL 60008
Phone: 1-855-922(WAC)-9001
www.weichaiamerica.com
(Natural Gas) (Liquid Propane Gas)
(Natural Gas) (Liquid Propane Gas)
1800RPM Fuel Consumption Curve
1500RPM Fuel Consumption Curve
4.5-LITER NA ENGINE DATA
2
4
6
8
10
12
14
16
18
200
250
300
350
400
450
500
550
600
7.5 13 26 31.3 39 44.1 50.2
Power (kW)
Total
Fuel（m³/h）
BSFC（g/kW.h）
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com

5. FEATURES
Engine & Block
• Cast Iron Block
• One-piece forged crankshaft
• Separate cast iron cylinder heads and wet cylinder liners
• Forged Connecting Rod
Cooling System
• Radiator and hoses supplied separately
• Thermostatically-controlled system with belt driven water
pump and Pusher/Puller fan
Lubrication System
• Flat bottom high capacity oil pan (16 L)
• Cartridge oil filter
• High capacity gear driven lube oil pump
Engine Control System
• Proven ECM, Fuel System and Engine Control
• Engine Protection
• CANBUS J1939 Standard Interface
• Telematics Compatibility
Air Intake & Exhaust System
• Rear Mounted, Replaceable Dry Air Cleaner
• Air Cleaner Restriction Indicator
Electrical System
• 12V electric starter motors
• Optional low voltage battery charging alternator
FLywheel & Housing
• SAE 1/SAE 3 flywheel housing and 11.5/10” flywheel
4.5-LITER NA ENGINE DATA
Model Number
Bore & Stroke
Displacement
Cylinders
Compression ratio
Governor Method
Fuel Type
Aspiration
Dry Weight
1800 RPM
HP
67
kW
50
HP
67
kW
50
PROPANE
NATURAL GAS
POWER RATINGS (PRIME)
56.1 in / 1,426 mm
43.2 in
1,098 mm
31.9 in / 811 mm
WP04GNA
4.13 in x 5.12 in (105 mm x 130 mm)
274 cid (4,500 cc)
4
9.75:1
ECM
Natural Gas / Propane
NA
1,102 lb (500 kg)
4.5LNA IRRIGATION
Weichai America Corp.
3100 Golf Road
Rolling Meadows, IL 60008
Phone: 1-855-922(WAC)-9001
www.weichaiamerica.com
67 HP @1800 rpm
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com