Solubility Changeswith Temperature

Compound

Sodium (from salt) Calcium Carbonate (lime)

Room Temp.

High

Low

Mineral scale occurs where heat transfer is greatest.

High Temp.

Very HighVery Low

Solubility at

Mineral Scale in CoolantPassage

Between the exhaust valves in a four-valve head is a notable area of high heat transfer. Therefore it is also an area susceptible to mineral scale deposits.

Cracked Heads From Abuse

The cylinder head cracked between the exhaust valves due to overheating because mineral scale deposits had accumulated in the water passages.

Mineral scale deposits can be prevented with proper inhibitor treatment. Cylinder heads will not crack if good quality fill water is used, and if the cooling system is properly treated with inhibitors.

Scaled Exhaust Guide

This water-cooled exhaust valve guide overheated due to the insulating factor from mineral scale deposits. Eventually the valve and guide overheated, the valve stuck in the guide, and the valve head broke off when it hit the piston.

Cooling Cylinder Head

0 10 20 30 40 50 60 70 80 90 100

% Reduction in Heat Transfer

0

0.02

0.04

0.06

0.08

0.1

0.12Scale Thickness (in.)CaSO4

CaCO3

Heat Transfer

SiO2

Failed Water Pump Seal

Corrosion

A natural, electrochemical breakdown of a metal, by which process it returns to its native state (its oxide form).

-

CathodeAnode

corroded

Electrolyte

(coolant)

protected

Volts- +

Metalions

Batteries Work on Principle of Corrosion

Your Cooling System is Like

a Battery !

CorrosionCurrents

Low OxygenConcentration

Crevice Corrosion

High oxygenconcentration area (dissolved in cooling water)

CavitationA purely mechanical process of erosion through the repeated collapse of vapor (gas) bubbles in a liquid.

Cavitation Principle

Cavitation Concept

In the case of a cylinder liner, the coolant pressure near the outside of the liner increases and decreases. This happens as the liner expands and contracts (vibrates) due to the pressure fluctuation within the cylinder.

• When cavitation occurs, flow drops off and wear occurs.

Cavitation ?

These water pump impellers have been totally destroyed by cavitations erosion. Water pumps experience cavitations when fluctuating pressures are created inside the water pump each time a blade passes by the housing. It is this fluctuation in pressure which creates and then collapses the vapor bubble. Often the tips of the impeller blades will erode first, since they come closest to the housing. When cavitations occurs at a water pump, the flow out of the pump drop off dramatically, allowing engine overheating to occur.

Chrome Resists Cavitation

• Harder material• 0.003 in (0.08mm)

Coolant Sampling

• Consistency• Clean piping• Six month intervals

or less.

Summary• Install balance lines.• Install coolant filters. • Use soft, clean fill (raw) water.• Use ethylene glycol if needed.• Use inhibitors as recommended by analysis.• Begin a coolant analysis program.• Keep the cooling system sealed.• Keep the coolant clean.

• Engine High Water Temperature

TroubleshootingTroubleshooting

Lubrication

Lubrication System

Lubrication System

Gear Type Oil Pump

Oil Pump & Relive Valve

Oil filter

Oil Cooler

Splash Lubrication

Oil Requirement

Oil Analysis

To understand our oil specifications, You need to know something about oil

Lubricating oils are formulated to provide specific functions in engines. Obviously, there is not one single oil specified to perform adequately in all engine types or application. Therefore, as a manufacturer we have to specify engine performance so oil manufacturers can meet these demands. It becomes your job to select the best oil to yield the desired performance.

Oil Viscosity

Ash CompositionAsh Composition• Calcium• Magnesium

Purpose: • Reduce valve recession• Neutralize acids

High Ash OilsHigh Ash Oils

Ash Greater Than 1.0%

Some lubricating oils are designated as high ash and can reach levels over 3%. This is considered a high amount of ash for gas engines. It is normally not recommended to run an engine with an oil designated as high ash unless it is necessary, such as if the fuel contains H2S. Watching your oil analysis can help determine whether high ash oils are required.Using high ash oil in an application that does not require it, can cause ash buildup in the combustion chamber and the valve faces.

Medium Ash OilMedium Ash Oil

Ash 0.35 - 1.0%

A more commonly specified lubricating oil is medium ash. This oil has much less ash content as compared to high ash oils. The vast majority of engines fall into the medium ash category. However, there are certain applications within these engine models that medium ash oils are not recommended.

Low Ash OilLow Ash Oil

Ash less than 0.35%

You may run engines with low ash oils, but they are restricted to naturally aspirated or catalyst equipped engines.

Ash will accumulate in the catalytic converter which will severely reduce its operating efficiency. The accumulating ash will prevent the exhaust from coming into direct contact with the active catalyst material. Zinc is a known poison to the catalyst, therefore the lubricating oil should not contain this element.

Note: Keep in mind that if you specify a lubricating oil to satisfy the requirements of the catalytic converter, increased valve wear and sleeve/piston ring wear may result.

Ashless OilAshless Oil

Less than 0.1% Ash

Engine has no recommendations for ashless oils in current production engines today. If these oils are operated in an engine, very high valve

recession and cylinder sleeve/ring wear may result.

TANTANTotal Acid Number

• Indicates the amount of acid present or suspended in the oil (Sulfur & Chlorine compounds)

TBNTBNTotal Base Number

• Scale to indicate the reserve alkalinity of the oil

• Select oil with a high alkalinity reserve of 7 to 13 TBN

Oil additive

• Lead sulfate on bearing overlay layer

• Early signs of damage

• Advanced acid attack

• Failed thrust bearings fromacid attack

• Failed piston pin bushing from sulfur attack

• Piston removed from engine operating

• 4,000 hours operation

NitrationNitrationNitrogen Dioxide is absorbed

in the oil

• Heavy varnish deposits• Raises oil viscosity

NitrationNitrationCommon Causes

• Lean air fuel ratios (stoichiometric engines)• Over extended oil service• Low operating oil temperatures

OxidationOxidationOxygen is absorbed in the oil

• Heavy varnish deposits• Hard deposits in ring area• Raises oil viscosity

OxidationOxidationCommon causes

• High operating lube oil temperatures(195o F. Max)

• Over extension of service

Base LineBase LineSend in new oil to be tested