How To Choose Lubrication Oil For Diesel Generator Set

Lubrication oil

Function                                                                           

General

 *Lower the friction    *Keep clean   *Rust protection  *Cooling    *Seal

Specific

  *Prevent deposits    * Prevent cylinder polishing   * Effective lubrication at high temp

 Effective lubrication

  at low temp start-up

 Prevent carbonised coal in:

- Piston ring grooves

- Piston skirt

- Valves

Oil production process (simplified)

Basic oil and Additive

Basic oil can be of mineral or synthetic type.

Additive gives the performance.

Example of additives

Antioxidants

Anti wear additives

Detergents

Dispersant

Corrosion inhibitor

Synthetic oils

Advantages

Good performance at high and low temperature

High viscosity index

Disadvantages

Expensive

Can affect the seals in the engine

Viscosity

Measurement of fluidity

Dependent of the temperature

Viscosity classes according to SAE standards

Singlegrade ”winter oil” SAE 10W (W=winter)
Singlegrade ”summer oil” SAE 40

Multigrade ”all year around oil” SAE 10W-40

SAE-no for engine oils

Specifications and Quality classification

API (American Petroleum Institute)

CCMC (Committee of Common Market Constructors)   European system.

ACEA (Association des Constructeures d´Automobiles)   replaces CCMC as from 1996-01-01

Lubrication oil service classes

Diesel engines

API CE, CF, CF-4, CG-4

CCMC D4, D5

CCMC PD-2 (Passenger car)

ACEA B1, B2, B3 (Passenger car)

ACEA E1, E2

Petrol engines

API SG, SH, SJ

CCMC G4, G5

ACEA A1, A2, A3

Difference between American and European demands

What happens to the oil during the combustion process

Piston ring and Cylinder liner wear

Piston ring wear

Poor oil quality

Poor fuel quality (high sulphur content)

Too long oil change intervals

Malfunction in the exhaust system, cooling system, inlet system

Cylinder liner polishing and glazing

Use of a poor oil quality

Low load running

Long idling periods

Carbon built up in piston ring grooves

Corrosion problems

Oil drain intervals

Alterations will occur. - Please see owners manual for each engine type.

Lubrication oil analysis

TBN  -  Total Base Number - the ability for the engine oil to neutralise acids

VISCOSITY

WEAR METALS

Fe-Iron:  Cylinder liner, camshaft,tappets,valve guides,crankshaft

PB-Lead:  Big end,Crankshaft bearing shells (all types of sliding bearings)

Cu-Copper:  Same as above

Sn-Tin:  Surface layer of sliding bearings

Cr-Chrome:  Piston rings, valve rods

Al-Aluminium: Pistons

Ni-Nickel:  The layer between the surface and copper on sliding bearing

Si-Silicone:  Sand, dirt etc

Insolubles:  Carbonised oil, Combustion residues, soot

H2O-Water:  Coolant water, Condensation water, water via blow-by

Fuel dilution: Incomplete combustion, leaking injectors

General effect of oil change interval

A

 Good oil quality

 Low sulphur content in fuel

 Efficient filtration

 Engine air supply

 Good operating duty

B

 Poor oil quality

 High sulphur content in fuel

 Long idling periods

 High frequency of cold start