Thermal Mapping Engine Compartments

Thermal Mapping Engine Compartments
By Ron Severtson (c) 2006

Thermal mapping of engine compartments is critical to extending life of electrical and electronic components. Drop the temperature of these components by just twenty degrees Fahrenheit and you double their life. High underhood temperatures during races may present performance issues which disappear after the race. Let's take a closer look under our hoods for answers.

Carmakers spend much time and money locating underhood components for best longevity. Racers may ignore this when installing new parts and this can result in hard to diagnose failures. Intermittent problems may come and go as components heat cycle. Engine performance falls off. Critical time is wasted chasing hard to find causes.

An infrared, non-contact thermometer, can be used to check temperatures of specific underhood components. Heat crayons are available to check temperatures from one hundred degrees Fahrenheit to well over two thousand degrees Fahrenheit. Small stick-on paper dots responding to specific temperatures can also prove useful. Powerful, computer driven CFD temperature programs are just now entering the marketplace.

Underhood components must be checked under the highest temperatures they experience. For street driven vehicles drive for at least one hour under varying conditions. Race vehicles should be checked when underhood temperatures are at their highest. Dirt, mud, oil, and grease all affect underhood temperatures and should be considered in the equation.

Components which have failed or are running hot must be located to a cooler place. This may involve moving them outside of the engine compartment if rules allow. You need to consider the possibility of other adjacent parts running hot after you move a component. Heat sinks can be also be used to control excessive component temperature.

I use graphing paper to record underhood temperatures by assigning an inch value to each square, which corresponds to the size of the engine compartment. Let's say our engine compartment is forty five inches long and sixty inches wide. Making each square equal to three inches wide by three inches high our example would be twenty squares wide by fifteen squares long. Using a ruler and a contrasting pencil I outline this space on the graph paper. A tape measure is used to map positions of underhood components with respect to the graph paper. Respective components are drawn in very close to their relative positions in the engine compartment. Copies are made and used to record underhood component temperatures with precision.

Thermal mapping saves money and increases your chances of finishing races. Try this technique and you just may find yourself winning more races!

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