Diesel Engines for Excavators



Weichai Power is the general application engine manufacturer with world’s advanced level, and is also the largest domestic power supplier for construction machinery.

After successfully developing special engines for scraper machinery, road construction machinery, lifting machinery and concrete machinery, Weichai focused on the domestic excavator development situation, researched on excavator working conditions and spent five years to launch whole series of engines for excavators. The quality, performance and cost of the engine are fully in line with the future trend of the excavators and it is the perfect substitute choice for imported engines.

Introduction to engines for excavators

1.WP5 & WP7

(1)WP5 & WP7 are jointly developed by Weichai Power, AVL, BOSCH and other world’s best auto parts suppliers. They are the full integrations of cutting-edge technology in today’s world diesel engine field.

(2)They are the ideal power for high-end small tonnage excavators.

Emissions: stage Ⅲ

Bore: 108mm

Stroke: 130mm

Displacement: 4.76L/7.14L

Power Range: 116 ~ 158Ps

158 ~ 270Ps

Rated speed: 2000r/min

2.WP5 & WP7 Features

(1)From the feasibility study to the reliability analysis, each of the WP5 & WP7 design process has been recognized by experts from AVL.

(2)Gantry structural body, integral cylinder head and other key parts all passed the advanced CAE finite element analysis, making full use of high intensity arc design and layout of vertical and horizontal stiffeners

(3)Integral cylinder head provides compact structure, high strength, good sealing and easy installation

(4)Four-valve intake and exhaust structure provides high air intake efficiency and low emissions


(1)WP12 is jointly developed by Weichai Power European R&D center and AVL. The performance is better than the current international standards and it is the only mature large displacement engine in China.

(2)It is the ideal power for high-end large excavators.

Emissions: stage Ⅲ

Bore: 126mm

Stroke: 155mm

Displacement: 11.596L

Power Range: 336 ~ 460Ps

Rated speed: 1900r/min

4. WP12 Features

(1)Frame structural main bearing layout ensures engine’s high strength and low noise.

(2)Adopt large diameter main journal and con-rod journal. The front shaft of the crankshaft has been strengthened so more powerful torque can be output.

(3)Split cylinder head structure brings maintenance convenience for customers. Four-valve intake and exhaust structure ensures the reasonable match between intake/exhaust system and combustion system, high air intake efficiency and low emissions.

5.Global supply chain of the key components

(1)Prestolite avalanche diode generators

(2)The fourth generation moderating starter motor of BOSCH

(3)Honeywell and Holset turbochargers

(4)BOSCH harness, connectors and injectors

(5)ATG piston rings, MIBA bearings and imported pistons

6.Fully applicable under the extreme environment – extreme high temperatures, extreme high altitude and extreme low temperatures

(1)High temperature adaptability

High flow water pump and advanced thermal equilibrium system can meet working conditions above 40 ℃.

(2)High altitude adaptability

All models are equipped with automatic bleed valve turbocharger that has high altitude mode, making sure that the power drop is less than 7% at 5000m altitude.

(3)Low temperature adaptability

Equipped with “three-stage easy fuel filter”, the excavators will be able to start smoothly under -40 ℃ of ambient temperature smooth start and effectively reduce the motor start failure rate under low temperature.

Eight technical innovations of engines for excavators

On the premise of taking full account of excavator engines’ reliability, economy, comfort and adaptability, the application of Weichai’s eight technical innovations could promote the upgrading of excavator power:

1.Three-stage easy fuel filter

Focused on the fuel the domestic excavator customer uses and the OEMs’ vehicle layout space, Weichai researched and spent two years on lab performance test, low temperature lab test, Heihe Cold Test and fuel suitability test, then finally successfully developed the one-piece “three-stage easy fuel filter” that is suitable for domestic markets.

2.External motor oil filter

Electric pump: prevent the oil pipe from not having any oil inside which will cause damages resulted from dry friction between operating parts when OEM test the vehicles or users replace the filter element. And extend engine life.

3.93 dust filter

(1)The centrifugal force of the cyclone strainer will remove the dust in the air.

(2)The centrifugal force of the swirl tube will again separate dust of smaller ion.

(3)Air filter fine filter element of the air filter will ensure the quality of the air that goes into the combustion chamber.

(4)Replacement cycle of the liner, piston, piston pin and piston rings will last three times longer.

4.Common-rail monitor

Seven functions can be realized with the help of common-rail monitor.

(1)Remote diagnostics – OK

(2)Stage management – OK

(3)Fuel Consumption Management – OK

(4)Vehicle Speed ​​management – OK

(5)Vehicle Location management – OK

(6)Vehicle Theft Warning – OK

(7)Abnormal Condition Warning – OK

The function can both be used independently and in combination.

5.Vibration-absorbing web

(1)Improve the overall stiffness of the cylinder block and reduce the overall vibration and noise of the cylinder block.

(2)Reduce the vibration of the cylinder block skirt area and reduce the oil sump vibration exciting force caused by engine block skirt area.

6.Divergence oil pan

(1)According to world’s most advanced oil pan design concept now, the oil pan is designed in divergent structure and will adapt WP7 installation requirements on the excavator.

(2)Reduce engine noise while reducing the overall engine height.

7.Packing boxes

(1)Packing box structure: wooden baffle and plywood box surface.

(2)The packing box is made of all kinds of wood oddments pressed under high temperature and high pressure. It has advantages of high strength, high load-bearing performance and good water resistance.

(3)The packing box would be flexible and highly adaptable for the goods.

8.Resistive-dissipative silencer

(1)The resistive-dissipative silencer is specially developed by major universities and Weichai Power, focusing on excavators’ power characteristics and combining the advantages of resistive damper and dissipative damper.

(2)Wide application range and excellent noise reduction effect.