TAKING A LOOK AT ENGINE COOLING
In this article, Davies Craig takes us through the importance of engine cooling
There have been many articles and countless discussions relating to internal combustion engines and how to keep them at a desired operating temperature, says Davies Craig.
In simple terms, horsepower generates heat which must be removed as quickly and efficiently as possible to ensure the engine does not overheat.
There are various aspects of an engine that should be examined when it needs to be kept cool. The radiator, the fan, the water pump and to lesser considered cooling accessories, an engine and/or transmission oil cooler.
Most original equipment manufacturers (OEMs) will advise the optimum engine temperatures will range from 90°C (195°F) to 105°C (220°F). Most temperature gauges don’t accurately show temperatures, only markings for cold and hot on the edges and a normal range in the middle. Cooling is essential as high temperatures damage and/or shorten the life of engine components and lubricants.
Firstly, Davies Craig suggests we discuss the radiator: brass, copper or aluminium – most car enthusiasts and weekend mechanics have heard this debate, it says.
“Arguments for either side range from heat transfer properties to price. In short, the OEM radiator should be sufficient as long as it is in good condition. We recommend you make sure it has been pressure-tested, is clean internally and externally,” Davies Craig Sales and Marketing Manager, John Benson, said.
“The coolant that goes into a radiator and subsequently the engine is also vital. Walk into any automotive aftermarket store and there will be rows of engine coolants staring you in the face, even waterless varieties. These products have anti-boil/anti-freeze, rust inhibitor qualities and are designed to perform in very cold and extremely hot climatic conditions.”
Ratios can vary and a 50/50 mix with distilled water is considered an acceptable mixture, says Davies Craig, which recommends you select a coolant which meets the OEMs recommendations while noting it is not recommended that coolants be mixed. It is advised that you flush out the cooling system at regular intervals.
Secondly, Davies Craig points to engine fans, noting that it is a commonly accepted practice that an electric Thermatic Fan be installed to carry out the very important function of driving an acceptable volume of air through the radiator.
“All IC engines have an optimum operating temperature and controlled air flow through the radiator during idling and slow travel speeds is one of the major factors to keeping an engine operating at a desired temperature,” John said.
“Controlled temperatures are also vital as higher engine temperatures shorten the life of components and break down engine lubricants. This becomes even more important in hotter climatic conditions. IC engines burn fuel hotter than the melting temperature of engine materials. Adequate engine cooling removes heat energy fast enough to keep temperatures manageable to preserve engine life.”
Davies Craig recalls the simple mantra: ‘one can never have too much air being drawn or pushed through a radiator’ and so advises you fill the core of the radiator with the largest fan or fans as is physically possible.
“Davies Craig has been manufacturing electric Thermatic engine Fans for the past 48 years and you can quickly access its range by clicking onto www.daviescraig.com.au,” John said.
Thirdly, another vital element to the engine cooling process is the water pump.
Most modern engines have a mechanical coolant circulation pump. Early engines relied on thermo-syphon cooling alone, where hot coolant left the top of the engine block and passed to the radiator, where it was cooled before returning to the bottom of the engine. Circulation was powered by convection alone.
Moving forward five plus decades and today’s basic mechanical water pump is not very sophisticated: a light metal impellor swirls around inside a belt-driven water pump cavity while its speed and subsequent coolant flow is determined by engine revs.
Davies Craig says one often sees buckets of money invested in the development of increasing engine horsepower and not a great deal of attention paid to another important part of the engine, the water pump.
Further, supercharging or turbocharging engines is becoming a very desirable method of increasing engine horsepower.
“Intercoolers are a usual requirement in these circumstances and electric booster pumps are usually installed to offer increased coolant circulation to assist with the overall engine cooling process. Electric vehicles too need to have their systems kept cool and the use of an electric booster pump is paramount,” John said.
Davies Craig says OEMs have paid limited attention to this aspect of the engine while other companies such as itself have dedicated significant resources over the past 20 years to produce a number of remote-mounted, lightweight Electric Water Pumps to suit a wide variety of engines.
Davies Craig states it has also sourced a number of brushless Electric Booster Pumps that suit both IC engines and electric vehicle cooling systems.
“Electric water pumps are the most productive way of eliminating parasitic power loss released when an iron-age mechanical water pump is replaced by electric water pump. Offering a more consistent coolant flow through an engine totally independent of the engine’s revs is not only efficient but vital if the engine temperature is to be managed in a more proficient manner,” John said.
“The Davies Craig patented LCD EWP/Fan Digital Controller will manage coolant flow commensurate with engine temperature and control the electric fan. Some OEMs have adopted electric water pump technology in some of their latest models.”
For more information, visit www.daviescraig.com.au