The Volvo Penta TMD 22B: The Diesel Engine On Board the Blue

The Volvo Penta TMD 22B is a marinized diesel engine specifically designed to offer reliability, efficiency, and performance in small to medium-sized boats, including sailboats. Its robustness and durability make it an excellent choice for long crossings or coastal navigation, where reliability is essential. Here you can consult their maintenance checklist

General Characteristics of the Engine

• Engine Type: 4-cylinder inline diesel.
• Cycle: Four-stroke.
• Intake System: Turbocharged.
• Nominal Power: 79 HP at 3000 rpm.
• Maximum Torque: Approximately 195 Nm at 1600 rpm.
• Total Displacement: 1.994 liters.
• Compression Ratio: 18.0:1.
• Approximate Weight: Around 250 kg.

The TMD 22B stands out for its ability to produce high torque at low speeds, making it ideal for harbor maneuvers, against-current departures, or in low-wind conditions. Its turbocharged design optimizes fuel consumption and improves overall engine performance.

Lubrication System

An efficient lubrication system is crucial for the longevity of any diesel engine. The TMD 22B is equipped with a differential rotor oil pump that ensures a constant supply of lubricant to all moving parts:

• Oil Capacity: Approximately 7 liters.
• Minimum Oil Pressure: 250 kPa at maximum speed and normal coolant temperature.
• Internal Clearances of the Oil Pump:
  • Outer rotor-housing: 0.30–0.36 mm.
  • Inner rotor-outer rotor: 0.025–0.082 mm.
  • Axial clearance:
  • Inner rotor: 0.030–0.075 mm.
  • Outer rotor: 0.05–0.10 mm.

Regular maintenance of the lubrication system, such as changing the oil every 100 hours or annually, is essential for optimal performance.

Cooling System

The TMD 22B uses a closed cooling system with a heat exchanger, protecting the engine from corrosion caused by saltwater:

• Coolant Capacity: Approximately 10 liters.
• Circulation Pump: Centrifugal pump driven by a belt.
• Seawater Pump: Rubber impeller, also belt-driven.
• Thermostat:
  • Begins opening at: 77°–85°C.
  • Fully open at: 92°–98°C.
  • Valve lift height, fully open: 9.1 mm.

This system ensures the engine operates within a safe temperature range, even under extreme conditions.

Fuel System

The direct injection system of the TMD 22B is one of its strongest features, allowing both efficient and powerful operation:

• Injection Pump: Bosch EPVE.
  • Pump element lift at TDC (TMD22B): 1.26 ±0.02 mm.
• Injectors:
  • Opening pressure: 22.8 ±5 MPa (Code JC).
• Fuel Pump: A.C. Delco, type YD, eccentrically driven from the camshaft.
• Fuel Filter: Bosch, spin-on type.

Fuel Efficiency

One of the standout features of the Volvo Penta TMD 22B is its excellent fuel efficiency, especially when operating within the typical cruising speed range of sailboats. Under normal operating conditions, where the engine runs between 1600 and 2000 rpm, the average fuel consumption ranges between 2 and 4 liters per hour. This performance makes it an excellent choice for long crossings, as it maximizes the sailboat's autonomy without compromising performance.

It is important to note that while the engine can reach up to 3000 rpm, these higher regimes are not typical during normal sailboat use, where fuel economy and engine durability are prioritized.

To achieve the best performance and minimize fuel consumption, it is recommended to operate the engine within its optimal efficiency range (approximately 1600–2000 rpm), where the balance between power and economy is ideal.

Electrical System

The electrical system of the TMD 22B is designed to provide sufficient energy for starting and auxiliary systems:

• Alternator: Valeo A13N 147M, 12V/60A (early version 12V/50A).
  • Direction of rotation: Clockwise, viewed from the drive end.
• Starter Motor: Lucas M80R, 12V.
  • Number of teeth on the gear: 10.
  • Maximum resistance of the starter cable at 20°C: 0.0017 ohm.
  • Brush length:
  • New: 9.0 mm.
  • Minimum permissible (used): 3.5 mm.
• Glow Plugs: Bosch, current after 20 seconds: 12A.

The electrical system is robust and reliable, ensuring easy starting even in cold conditions.

Turbocharging System

The turbocharger of the TMD 22B significantly enhances its performance compared to naturally aspirated variants:

• Manufacturer: Garrett.
• Lubrication System: Force-feed lubrication from the engine.

The turbo allows the engine to deliver superior power without increasing displacement, improving both efficiency and available torque.

Maintenance and Reliability

The TMD 22B is known for its ease of maintenance and durability. Key recommendations include:

• Change the oil every 200 hours or annually.
• Check and replace the air and fuel filters periodically.
• Verify coolant levels before each trip.
• Inspect the turbocharger and injection system to ensure optimal performance.

Conclusion

The Volvo Penta TMD 22B is a marinized diesel engine designed to offer the perfect balance of power, efficiency, and reliability. Its ability to produce high torque at low speeds makes it ideal for sailboats, where precise maneuvering and performance in adverse conditions are critical. With proper maintenance, this engine can provide years of reliable service at sea.

If you own a sailboat equipped with a TMD 22B, you can be confident that you have a robust and efficient engine that will accompany you on your nautical adventures. ¡Bon voyage!