Technical notes of interest to Marine Engineers
Maintenance guide for high speed Diesel prime movers
Compiled by: Martin Leduc
Brought to you by www.dieselduck.net, comments to [email protected]
These recommendation were specifically designed for a Cat D379. Which is a diesel fuel burning, V8, turbocharged, engine running at 1200 rpm, producing about 600 bhp. Engineers can use these maintenance guidelines for similar sized engines should they not be in possession of the OEM's maintenance recommendations.
Maintain a record of "fuel used", "service hours" or "time interval". Use one of these to provide a consistent benchmark for maintenance so as to prevent "lack of maintenance" and "over maintenance".
Daily
Check level
Engine oil Engine coolant Marine gear oil Air starter lubricator oil (if equipped)
Governor oil (if equipped)Air tank - drain water Inspect for leaks and loose connections
Inspect engine air cleaner indicator - check
Oil filter differential pressure - checkClutch shift collar - lubricate
Every 5300 L (1400 gal) of Fuel
50 Hours
Zinc Rods - Inspect/Replace Marine gear oil and filter - clean strainer / change on new or rebuilt marine gears at first 50 hours only, then at normal interval thereafter. Every 13 260 L (3600 gal) of Fuel
125 Hours
Clutch - check / adjust Lubricate clutch control Lever, clutch main shaft bearing and clutch pilot bearing. Every 26 500 L (7000 gal) of Fuel
250 Hours
Batteries - clean / inspect and check electrolyte level Belts, hoses and radiator fins (if equipped) - inspect / check Fuel pressure gauge - check
Coolant additive - check and add as neededFuel tank and fuel filter housing - drain water and sediment Every 79 500 L (21,OOO gal) of Fuel
750 Hours
Engine oil and filters - replace
Duplex oil filters - replaceValve lash and rotators check / adjust (at first oil change only) Crankcase breather - clean Primary fuel filter - clean Every 106 000 L (28,000 gal) of Fuel
1000 Hours
Engine protective devices - inspect / check
Marine gear oil and filter - replaceGovernor oil (if equipped) - replace Marine gear strainer and breather - clean Marine gear output shaft seal, governor air Actuator, tachometer drive and shutoff control lever - lubricate Every 212 000 L (56,000 gal) of Fuel
2000 Hours
Valve lash - check / adjust
Engine mounts, damper, valve rotators
Turbochargers - inspectFuel filters - replace Every 318 000 L (84,000 gal) of Fuel
3000 Hours - Two Years
Cooling system - clean / flush Thermostats - replace Every 424 000 L (112,000 gal) of Fuel
4000 Hours
Air compressor and electric starter - inspect / rebuild or exchange if necessary
Nozzles - testEvery 636 000 L (168,000 gal) of Fuel
6000 Hours
Alternator, water pump, sea water pump (centrifugal), air starter and turbochargers inspect / rebuild or exchange if necessary Every 1,060,000 L (260,000 gal) of fuel
10,000 Hours
Top end - cylinder heads and after cooler core inspect / rebuild or exchange if necessary Every 2,120,000 L (560,000 gal) of Fuel
20,000 HoursOverhaul, inspect / rebuild or exchange if necessary
cylinder heads
connecting rods
cylinder linerspistons turbochargers cam followers fuel transfer pump pre-lube pump fuel injection system and governor wrist pins main oil pump Install new
piston rings
main bearings rod bearings valve rotators
crankshaft seatsInspect
crankshaft
camshaftcam Bearings damper gear train rocker arm bushing bushings and driven unit alignment Clean / test
oil cooler
after cooler corefuel nozzles As you can well imagine, it's easy for an engine company to increase your maintenance task so your engine doesn't fail on you making you curse them. But once you have established a set routine, the recommended intervals may be adjusted to be more in line with the actual need. This is called "condition based maintenance".
Valve readings / adjustments on a six cylinder, four stroke engine, like a Cat 3406
Taking valve reading / adjusting can be a labour intensive task: take readings turn the engine, take readings turn the engine, on and on until all six cylinder are done. Well, start printing this page because were going to shorten the task.
Harmed with a "go no go" feeler gauge and the manufacturer's recommended specs for the intake and exhaust valves...
Set the engine to #1 top dead center (TDC) - valves on #6 are rocking and #1's are loose.
Measure and adjust
intake valves on cylinder #1, 2, 4 exhaust valves on # 1, 3, 5. Bar the engine over to #6 TDC, 360 degrees - valves on #1 are rocking and #6's are loose.
Measure and adjust
intake valves on cylinder #3, 5, 6
exhaust valves on # 2, 4, 6...for a Caterpillar 397
Bore 6.25 (158.8mm), Stroke 8.00 (203.2mm)TDC #1
Exhaust to check � 4, 8, 1, 5
Intake to Check � 2, 6, 1, 3360� TDC #1
Exhaust to check � 2, 6, 3, 7
Intake to Check � 4, 8, 5, 7...that's it. Quick and painless.
Genset maintenance
I've created this quick checklist to help me when carrying out maintenance on our ship's gensets. Most gensets on the smaller vessels I've worked on were 150 kW units typically powered by a Cat 3306, Detroit Diesel 8V92 or the likes (high speed diesel, four or two stroke, turbo charged). The maintenance interval for oil changes ranged between 300 - 400 hours and included the following:
Take SOS (Schedule Oil Sampling) sample prior to shutting down. SOS is optional and "expensive", but properly used, it can provide a clear picture of the engines condition and provide information to alter your maintenance practices.
Change oil and filterDrain fuel / water separator (Racor) of water and dirt. Change filter every other service (600hrs - Racor recommends every 500hrs but we've run them up to 1300hrs)
Check governor mounts, clevis pins and connections. A runaway engine can ruin your day - been there, done that.
Check air intake filter. Replace if you can't see daylight through the edge of the pleats.
Check turbo end play for axial and radial play. Gently push / pull and try to move the end of the turbo shaft sideways - tight is good, but some play is allowed - check your manual for specs. Also check condition of compressor blades - foreign object damage and cracks.
Check fresh water header tank for level and proper conditioning. You don't specifically need antifreeze (glycol) but your diesel does need a conditioning agent. Cat Alcool or Drew Chemical's Maxi Guard are both solution which provide conditioning. If you do have glycol in your engine, keep it at 50% water, 50% anti freeze and you will need additional conditioning.
Check / replace zincs on raw water system. Check all the plugs around the sea water piping and heat exchanger they might need new zincs to prevent galvanic destruction.
Check engine mounts. Detroits are particularly bad for this. Lightly tap each engine / generator mount bolts with a small ball peen hammer - "ping" = good (tight), "thud" = bad (loose). While you're at it, do a visual on the all the engine's piping and connections.
Check alternator end for loose connections, chaffing and dust build up. Take some of the housing covers off and do visual inspection, blow out dust with compressed air. Some generators have air filters, check and replace as necessary.
Log your efforts. Not for praise, but for record keeping - so you won't do it too often or not enough !Brought to you by www.dieselduck.net, comments to [email protected]