Chapter 11, Engine Cooling Systems

pencool

SCA supplemental coolant additive

fanstat

a combination temperature sensor and switch used to control the engine fan cycle usually pneumatic

double pass radiator

a counterflow radiator in which the coolant is routed to make two passes they're for entering and exiting from separate tanks both located either at the top or the bottom of the radiator a high-efficiency radiator

counterflow radiator

a double pass Radiator in which coolant is cycled through you column tubes from usually a bottom located and take tank to a bottom located output tank. they have higher cooling efficiencies then other radiator designs

thermatic fan

a fan with an integral temperature sensing mechanism that controls its effective cycle

radiator

a heat exchanger used in liquid cooled engines designed to dissipate some of the engines rejected lead to atmosphere

propylene glycol

a less toxic glycol based antifreeze solution than EG . PG mixture strength must be tested with a refractometer with PG scale and not mixed with EG.

antifreeze

a liquid solution added to water to blend the engine coolant solution that raises the boiling point and lowers freezing point. ethylene glycol propylene glycol and extended life coolant are currently used.

actively pressurized cooling system

a means of increasing diesel engine cooling capacity by pressurizing the cooling system using boost air to raise the boiling point of the antifreeze mixture.

Universal coolant

a premix anti-freeze that can be blended with any EG or PG based product without any negative impact on its performance properties

thermostat

a self-contained temperature sensing coolant flow modulating device used to manage coolant flow within the engine coolant system

shutter stat

a temperature sensing pneumatic switch used to manage air shutter operation

downflow radiator

a typical Radiator in which hot coolant from the engine enters at the top tank flows downward and exits through a bottom tank

crossflow radiator

a usually low profile design of radiator and which the entry and output tanks are located at either end and coolant flow is horizontal.

Ram Air

air fed into engine Cooling and intake circuits by the velocity of a moving vehicle increases proportionally with vehicle speed

waterless engine coolant

an EG and additive coolant anti-freeze premix designed to last the life of the engine with little or no maintenance achievable if the solution is never contaminated with water or other types of anti-freeze

ethylene glycol

an antifreeze of higher toxicity that the EPA hopes to phase out but as yet is commonly used

hydrometer

an instrument designed to measure the specific gravity of liquids usually battery electrolyte and coolant mixtures it is not recommended for measuring either and truck engine applications where a refractometer is the appropriate instrument due to Greater accuracy

refractometer

an instrument that uses light to measure the refractive index of liquids it is regarded as a more reliable means of testing battery electrolyte and anti freeze protection

heat exchanger

any of a number of devices used to transfer heat from one liquid to another where there is a temperature difference using the principles of conduction and radiation

single pass radiator

any radiator through which flow is unidirectional

supplemental coolant additives

conditioning chemicals added to anti-freeze mixtures

extended life coolant

coolant premix that claims a service dive of up to six years with almost no maintenance

cavitation

describes metal erosion caused by the formation and subsequent collapse of vapor pockets (bubbles) produced by physical pulsing into a liquid such as that of a wet liner against the wall of coolant that surrounds it. Bubble collapse causes high unit pressures and can quickly road wet liners when the protective properties of the coolant diminish.

total dissolved solids

dissolved minerals measured in a coolant by testing the conductivity with a current probe High TDS counts can damage moving components in the cooling system such as water

reversible fans

engine compartment varible pitch cooling fans using a thermatic principal to determine blade pitch and cleaning mode a blade pitch effectively reverses the underhood air movement allowing the fan to blow dirt and debris from Heat exchangers

convection

heat transfer by currents of gases or liquids

conduction

heat transmission through solid matter

diesel coolant additive

proprietary supplemental coolant additives

rejected Heat

that portion of the potential heat energy of a fuel not converted into a useful kinetic energy

kinetic energy

the energy of motion

refraction

the extent to which a light-ray is deflected or bent when it passes through a mediums such as water coolant or fog

headers

the manifold deck to which the coolant tubes are attached in the heat exchanger bundle or the term used to describe low gas restriction individual cylinder exhaust pipes that converge at a point calculated to maximize pulse effect

radiation

the transfer of heat or energy by Raze not requiring matter such as a liquid or a gas

pH

used to evaluate the acidity or alkalinity of a substance from a logarithm of the reciprocal of the hydrogen ion concentration in a solution in moles per liter. p = power, H = hydrogen