An excavator engine is a turbocharged intercooled diesel engine, the main power source for driving hydraulic pumps, travel and working devices. Core features:

1. Low speed, high torque
2. Fuel-saving, heavy-load durable
3. Turbocharged + Common Rail injection
4. Meet EU Stage V / China National IV emission standard (with DPF / SCR after-treatment)

2. Main Brands & Typical ModelsibaR
Caterpillar (CAT)ibaR
Models: C4.4, C6.6, C7.1, C9.3, C13

1. Full in-house design
2. Mining-grade heavy duty
3. Long service life: 15,000–20,000 hours

KomatsuibaR
Models: SAA4D95, SAA6D107, SAA6D125

1. Low noise, high fuel efficiency
2. Matched perfectly with Komatsu hydraulic system

IsuzuibaR
Models: 4JJ1, 6BG1, 6HK1, 6WG1

1. Super reliable, easy maintenance
2. Good cold-start performance
3. Widely used in most Chinese & Japanese excavators

YanmaribaR
Models: 4TNV94, 4TNV98, 4TNV106

1. Mainly for mini & small excavators (6–15 ton)
2. Compact size, low fuel consumption

CumminsibaR
Models: B3.9, QSB6.7, QSL9

1. Used widely on Sany, XCMG, LiuGong
2. Strong power, good for mining and heavy earthwork

VolvoibaR
Models: D4, D6, D8, D12

1. Low noise, eco-friendly
2. Matched with Volvo intelligent hydraulic system

3. Basic Structure

1. Cylinder block & cylinder head
2. Piston, connecting rod, crankshaft
3. Turbocharger + Intercooler
4. Common rail fuel injection system
5. Air filter, fuel filter, oil filter
6. Emission after-treatment: DPF, SCR

4. Working Principle (4-Stroke Diesel Cycle)

1. Intake – Clean air enters cylinder
2. Compression – Air compressed to high temperature
3. Power – Diesel injected and auto-ignited, push piston down
4. Exhaust – Waste gas discharged

5. Key Parameters (20-ton Excavator)

1. Displacement: 5.9–7.1 L
2. Rated power: 110–130 kW (150–175 HP)
3. Rated speed: 2000–2200 rpm
4. Max torque: 550–650 N·m @ 1200–1500 rpm
5. Intake: Turbocharged + Aftercooled
6. Emission: EU Stage V / China IV

6. Common Faults

1. Black smoke: Dirty injector, air filter blocked
2. Overheating: Coolant lack, radiator dirty
3. Power weak: Turbo damage, fuel filter clogged
4. Engine knock: Injector failure, poor diesel quality

7. Daily Maintenance

1. Replace engine oil & oil filter every 250–500 hours
2. Clean air filter every 50 hours, replace every 200 hours
3. Replace fuel filter every 1000 hours
4. Use standard diesel and engine oil (CH-4 / CI-4 grade)