Essential MAN B&W Engine Maintenance for Optimal Performance

MAN B&W Engine Maintenance

Maintaining a MAN B&W engine is crucial to ensuring its efficiency, reliability, and longevity. Proper upkeep of these high-performance engines requires regular attention to various components, from cylinder liners to the cooling system, and each part must be meticulously inspected, cleaned, and serviced according to a structured schedule. In this guide, we provide a step-by-step breakdown of essential maintenance procedures for MAN B&W engines, ensuring your engine runs smoothly, reduces downtime, and performs at its peak. Whether you’re conducting routine inspections or preparing for major overhauls, this comprehensive maintenance checklist will help you keep everything running as it should.

Hourly Scheduled Maintenance (0 – 16,000 Hours)

Cylinder Liner

1. Dismantle and inspect all cylinder liners.
2. Hone the cylinder liners.
3. Record measurements of cylinder liners.

Piston and Piston Rings

1. Withdraw all pistons for inspection and overhaul.
2. Decarbonize pistons.
3. Clean piston and oil scraper ring grooves; inspect for wear using a testing mandrel to ensure they meet acceptable tolerance.
4. Replace all piston and scraper rings before reinstalling pistons.
5. Confirm piston ring positions offset 180° from each other and ensure the scraper ring spring joint is fitted 180° offset to the ring joint.
6. Open all plugs and apply new glue (Loctite 2701) after cleaning the holes and plugs with Loctite 7063. Tighten plugs with a torque of 100Nm.
7. Perform ultrasonic testing of piston pins (external agency).
8. Change retaining rings for all pistons.

Connecting Rod

1. Inspect and measure big-end bore diameter.
2. Inspect small-end bearings and check clearance between the piston pin and bush, with readings enclosed.
3. Visually inspect all connecting rod bolts and nuts for abnormalities.
4. Check tightness of all machining holes and blank screws.

Cylinder Heads

1. Remove and clean all cylinder heads.
2. Inspect inlet and exhaust valve spindles, machining/replacement as required.
3. Check valve rotators for rotation and repair/replace defective Robocap parts, including springs, balls, and pressure plates.
4. Overhaul safety valves and adjust the opening pressure to 175 bars.
5. Inspect indicator valves.
6. Inspect and machine/replace valve seats as necessary.
7. Perform pressure testing of all cylinder heads.
8. Remove, clean, and inspect water guide jackets, replace with new O-rings as needed.
9. Inspect and replace nipples.
10. Tighten cylinder head nuts to the prescribed torque.

Camshaft and Camshaft Bearings

1. Inspect gear wheels, bolts, and connections for abnormalities.
2. Measure and record bearing clearances.
3. Check the condition of cams.
4. Verify lubrication of the camshaft, ensuring the flow of oil from all bearings and spray pipe nozzles.
5. Check tightness of all screws, nuts, and bolts.
6. Inspect push rods.
7. Adjust inlet valve clearance to 0.4mm and exhaust valve clearance to 0.9mm.

Operating Gear for Inlet Valves, Exhaust Valves, and Fuel Injection Pumps

1. Inspect roller guides for valve gear:
   • Look for marks or scores due to seizure.
   • Check for deformation on spherical studs.
   • Inspect the surface of rollers for any marks or deformation.
   • Ensure free play between rollers, bushes, and pins.
2. Inspect valve bridge springs, rocker arm brackets, and push rods for abnormalities.
3. Inspect roller guides for fuel injection pumps:
   • Check for marks or scores due to seizure.
   • Inspect roller surfaces for marks or deformation.
   • Ensure free play between rollers, bushes, and pins.
4. Check lubrication of all operating gears.

Governor

1. Inspect the governor drive.
2. Change the governor oil after flushing.
3. Inspect and tighten linkages and foundation bolts.
4. Overhaul the governor (external agency).

Crankshaft and Main Bearings

1. Inspect crankpins.
2. Check main bearing alignment (autolog) and realign crankshaft if necessary.
3. Replace all main bearing shells, including guide bearings.
4. Retighten counterweights to a prescribed torque of 300Nm.
5. Retighten main and guide bearing caps to the prescribed torque of 900 bars.
6. Clean crankpins and check for abnormal scoring marks.

Turbochargers

1. Remove both cartridges.
2. Remove nozzle rings and replace them.
3. Dismantle TC cartridge for bush and labyrinth seal replacement.
4. Reassemble the cartridges.
5. Measure and record clearances.
6. Clean the Charge Air Cooler (CAC).
7. Perform a pressure test on the CAC.
8. Clean air intake filter room inertia louvers and replace the oil.

Engine Frame and Bed Plate

1. Retighten holding-down bolts.
2. Retighten bolts between the engine and base frame.
3. Overhaul safety covers.
4. Change O-rings of camshaft inspection doors and CC doors.
5. Retighten and measure all conical (AVM) bolts.

Fuel Oil System and Injection System

1. Check fuel injection valves, adjust opening pressure, and change nozzles. Inspect and replace thrust spindles and springs.
2. Change O-rings on all fuel valves.
3. Inspect and change fuel high-pressure pipes and O-rings.
4. Measure and record the nominal height of all fuel injection pumps.
5. Overhaul nozzle cooling pump:
   • Replace seals and bearings.
   • Replace coupling.
   • Overhaul the motor.

Lubricating Oil System

1. Inspect the engine-driven lubricating oil pump and replace bushes.
2. Replace all lubricating oil filters.
3. Clean the Lube Oil Cooler (LOC).
4. Clean the centrifugal filter and replace the PRV kit.
5. Overhaul the pre-lube oil pump:
   • Overhaul the motor.
   • Replace pump seal.
   • Replace coupling.

Cooling Water System

1. Overhaul the LT water pump.
2. Clean the Plate Heat Exchanger (PHE).
3. Check thermostatic elements for 820°C stamping and replace if required.
4. Inspect and replace the O-ring of the LT water thermostat.
5. Replace cooling water nipples in the exhaust manifold if necessary.

Exhaust System

1. Clean the complete exhaust manifold and replace intermediate pieces if eroded by cold corrosion.

Compressed Air System

1. Overhaul the air starting motor and replace the overhaul kit.
2. Overhaul and replace the PRV kit for the main air starting valve.

Alternator

1. Clean and replace bearing grease as needed.

Miscellaneous

1. Record fuel pump index at Governor Index 0.
2. Overhaul the turning gear:
   • Change motor bearings.
   • Overhaul mechanical turning gear.
3. Perform a functional test of all safety shutdown switches and analog switches.

Post-Maintenance Procedures

1. Start the engine for trial runs. Check and verify the operation of all mechanical and electrical safety devices.
2. Follow the MAN B&W standard procedures for all moving parts during startup.
3. Perform load trials of the engine following the MAN B&W protocol.
4. Record engine performance and measurement data at various loading stages.

Once the trial runs are completed and satisfactory, hand over the engine to the customer for normal operation.

MAN B&W Engine Maintenance Schedule (0 to 16,000 Running Hours)

Regular maintenance is essential to ensure the optimal performance, reliability, and longevity of MAN B&W engines. A comprehensive maintenance schedule based on running hours helps prevent unexpected failures and ensures all components function efficiently. Below is a detailed maintenance schedule for MAN B&W engines, covering the first 16,000 running hours.

0 to 2,000 Running Hours Maintenance:

This initial phase focuses on basic inspections and adjustments to ensure the engine is running smoothly after its initial break-in period.

Component / Task	Maintenance Action	Frequency
General Engine Check	Inspect engine performance data, monitor parameters	Ongoing
Cylinder Head	Inspect cylinder head bolts and retighten	2,000 hrs
Inlet/Exhaust Valves	Overhaul and check valve operation, regrind spindle & valve seats	2,000 hrs
Piston and Rings	Inspect piston, piston rings, flame rings, and scraper rings for wear	2,000 hrs
Connecting Rods	Check big-end bearings and measure big-end bore	2,000 hrs
Main Bearings	Inspect main bearings and check alignment	2,000 hrs
Lubricating Oil	Check and change lubricating oil filter	2,000 hrs
Cooling System	Check cooling water system and pump	2,000 hrs
Fuel Oil System	Clean fuel oil filters and inspect fuel system	2,000 hrs

2,000 to 8,000 Running Hours Maintenance:

At this point, the engine will require more extensive checks and cleaning of components that are subjected to continuous wear.

Component / Task	Maintenance Action	Frequency
Cylinder Liner	Clean, hone, and measure the cylinder liner	8,000 hrs
Piston and Rings	Replace worn piston rings and inspect piston pin and bush	8,000 hrs
Camshaft	Inspect camshaft for wear, check bearings and lubrication	8,000 hrs
Fuel Injection System	Dismantle and clean fuel injection pump	8,000 hrs
Turbocharger	Clean turbine and compressor side, inspect and wash	8,000 hrs
Crankshaft & Main Bearings	Check main bearing and crankshaft for wear and alignment	8,000 hrs
Cooling System	Replace the thermostatic valve and check cooling water flow	8,000 hrs
Lubricating Oil	Change lubricating oil, inspect cooler and filter	8,000 hrs
Auxiliary Equipment	Check operation of all auxiliary equipment in the engine room	8,000 hrs

8,000 to 16,000 Running Hours Maintenance:

This phase will require more significant overhauls, including checks on all critical components and replacements if necessary.

Component / Task	Maintenance Action	Frequency
Cylinder Head	Inspect and retighten cylinder head bolts, check cooling water space	16,000 hrs
Inlet/Exhaust Valves	Inspect and adjust valve clearance, check valve guides for wear	16,000 hrs
Piston and Rings	Inspect and replace worn piston rings, piston pin, and connecting rod bush	16,000 hrs
Cylinder Liner	Inspect cylinder liner for wear, replace if necessary	16,000 hrs
Fuel Injection System	Overhaul fuel injection system, check nozzle opening pressure	16,000 hrs
Crankshaft & Main Bearings	Overhaul and inspect main bearings, crankshaft alignment, and counterweights	16,000 hrs
Camshaft and Bearings	Inspect camshaft for wear, check bearing clearance, lubricate	16,000 hrs
Lubricating Oil System	Change lubricating oil, replace filters, check cooler	16,000 hrs
Turbocharger	Clean and inspect turbocharger completely, wash and service	16,000 hrs
Cooling System	Flush cooling system, check pump and thermostatic valve	16,000 hrs
Exhaust System	Inspect exhaust piping, compensators, and turbocharger connections	16,000 hrs

Ongoing Maintenance Checks (Daily, Weekly, Monthly)

In addition to the scheduled running-hour maintenance, daily, weekly, and monthly checks are necessary for keeping the engine in optimal condition.

Component / Task	Action	Frequency
Engine Parameters	Monitor engine data and check operating conditions	Daily
Fuel System	Inspect fuel filters, check fuel oil for contamination	Weekly
Lubricating Oil	Check oil level and quality, change if necessary	Monthly
Cooling System	Check cooling water levels and system operation	Monthly
Air System	Inspect air filters, clean air intake systems	Monthly

Overhaul and Replacement Guidelines:

Overhaul schedules should also align with the total operating hours or specific time intervals. Based on the running hours, certain components will need to be replaced or overhauled more frequently:

• Repeat 2,000 hours maintenance: This should include the tasks mentioned under 8,000 hours maintenance.
• Repeat 8,000 hours maintenance: Includes tasks mentioned under 16,000 hours maintenance.
• Repeat 16,000 hours maintenance: Should cover tasks for 32,000 hours if the engine reaches this milestone.