The Caterpillar M 20 C is a 9.4 L 6-cylinder turbocharged and intercooled (single-pipe / single log charging) engine rated at 900 rpm. It powers generator sets from Caterpillar, including the 6 M 20 C, 8 M 20 C and 9 M 20 C.
Also known as: Caterpillar / MaK M 20 C
| Displacement | 9.4 L |
|---|---|
| Cylinders | 6 |
| Aspiration | Turbocharged and intercooled (single-pipe / single log charging) |
| Rated speed | 900 rpm |
Compiled from service & troubleshooting documentation across every generator set that uses the Caterpillar M 20 C.
| Item | Action | Hours | Months | Notes |
|---|---|---|---|---|
| Turbocharger compressor | Clean | 24 hr | Water is fed before compressor wheel via injection pipes during full load operation every 24 hours. | |
| Turbocharger turbine blade and nozzle ring | Clean | 150 hr | "Wet cleaning" with clean fresh water during low load operation at regular intervals of 150 hours, depending on fuel quality. Cleaning in 3-4 intervals of 30 seconds each; fresh water of 2-2.5 bar required. | |
| Engine / engine generator set corrosion protection | Inspect | 3 mo | Every 3 months specific inspections are to be carried out at the engine or engine generator set at defined inspection points; any corrosion and condensation water are to be removed immediately. |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Other | Clutch slipping time (T2) | minimum 3 | s | |
| Other | Vibration acceleration aeff | < 44.2 | m/s² | f > 250 Hz < 1000 Hz |
| Other | Vibration displacement Seff | < 0.448 | mm | f > 2 Hz < 10 Hz |
| Other | Vibration velocity Veff | < 28.2 | mm/s | f > 10 Hz < 250 Hz |
| Pressure | Charge air pressure | 3.3/3.4 | bar | |
| Pressure | Cooling water pressure at engine inlet min/max | 2.5/6.0 | bar | |
| Pressure | Firing pressure | 185 | bar | |
| Pressure | Max. pressure loss incl. silencer and exhaust gas boiler | 30 | mbar | |
| Pressure | Maximum exhaust gas pressure drop | 0.03 | bar | |
| Pressure | Minimum starting air pressure | 7 | bar | |
| Pressure | Starting air pressure max. | 30 | bar | |
| Pressure | Working pressure at engine inlet (lube oil) | 4 - 5 | bar | |
| Speed | Clutch-in speed of engine | min. 70 | % of rated speed | |
| Speed | Maximum continuous rating speed | 900/1,000 | 1/min | |
| Speed | Minimum speed | 280/300 | 1/min | |
| Temperature | Cooling water temperature at engine outlet | 80 - 90 | °C | |
| Temperature | Lube oil temperature at engine inlet | 55 - 65 | °C | |
| Temperature | Temperature at LT charge air cooler inlet | 38 | °C | |
| Temperature | Temperature at engine inlet (final preheater HH1/HH2) | max. 150 | °C |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Fluid | Grade | Standard | Ambient | Capacity | Notes |
|---|---|---|---|---|---|
| Coolant | Caterpillar coolant regulations for MaK engines | Distillate or freshwater free from foreign matter (no sea water or waste water); total hardness of max. 10° dH; pH-value 6.8 - 8; chloride ion content of max. 50 mg/l. Anti-corrosion additive treatment required before first commissioning. | |||
| Engine oil | SAE 40 | MaK Operating Media (approved oil list) | 1.3 l/kW output | TBN must be between 30 and 40 KOH/g at HFO operation; for MDO operation the TBN is 12 - 20 depending on sulphur content. Recommended/circulating quantity approx. 1.3 l/kW output with separate tank. | |
| Fuel | LCV = 42700 kJ/kg | MaK technical data; without engine-driven pumps, tolerance 5% | |||
| Fuel | 35° API gravity at 60°F (16°C) | LHV 18,390 Btu/lb (42 780 kJ/kg) | Fuel at 85°F (29°C) weighing 7.001 lbs/U.S. gal (838.9 g/liter) | ||
| Fuel | HFO (residual fuel) | CIMAC H55 K55; ISO 8217:2010 (E); ISO-F-RMH55 RMK55 | Heavy fuel operation up to 700 cSt/50°C. | ||
| Fuel | MGO/MDO | ISO 8217:2010 (ISO-F-DMA / -DMB / -DMZ); ASTM D 975; DIN EN 590 | Min. injection viscosity 1.5 mm²/s (cSt); max. injection viscosity 12 mm²/s (cSt). |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
The Caterpillar M 20 C has a displacement of 9.4 liters with 6 cylinders.
The Caterpillar M 20 C powers 3 generator set(s), including Caterpillar 6 M 20 C, Caterpillar 8 M 20 C, Caterpillar 9 M 20 C.
A commonly reported issue on generators using the Caterpillar M 20 C is: Voltage failure at terminal X3 - alarm.