Tech Tips by Aussie Desert Cooler
Overheating causes 90% of engine failure.
Are you really overheating? The first step you should take unless there is steam pouring out of your bonnet is to have your gauge checked. Most factory gauges are merely an indicator and not all that accurate. A good quality after market gauge is recommended. Keep in mind in most cases engines like to run between 180-190 degrees Fahrenheit.
Don't throw your thermostat away! Thermostats are needed to keep your motor in the optimum temperature range - this avoids wear and tear and promotes efficient running.
Thermostats are not recommended with electric water pumps. A thermatic controller is normally used with electric water pumps. This speeds up or slows down the pump depending on the temperature of the engine.
To test your Thermostat
Put the thermostat in a pot of water. Heat the water. Use a thermometer so that you know the temperature of the water and watch for the thermostat to open. That way, you know that the thermostat does open and at what temperature it opens.
Overheating at High Speed
In most cases, overheating at high speed is a radiator capacity problem. Either your radiator is blocked or just not big enough to do the job. More horsepower equals more heat! If you have just raised the compression of the motor by either running high comp pistons, turbo or supercharger, you have just created more heat that you have to get rid of.
You most likely need a high performance radiator to get rid of the extra heat.
Overheating at Low Speed
Low speed overheating problems are usually due to bad air flow or poor quality water pump. A poor quality water pump will tend to cavitate which will create a bad heat transfer.
Beware of buying race style water pumps - they are exactly that - great for racing at 6000 plus revs but no good for cruising the streets.
Water pump pulley sizes
In Australia, as a general rule, we recommend a water pump pulley 10% smaller than a harmonic balance pulley. This will usually give you the correct water pump speed for our climate.
Electric Water Pumps
Electric water pumps are great for keeping a constant cycle in your cooling system. Whether the motor is pulling 7000 revs or its just idling the electric water pump runs at the same speed.
Electric water pumps are great for performance engines in street applications.
A normal engine fan is usually fine providing the radiator has a shroud. The shroud acts as a big suction cup at low speed. Thermo fans are far more effective at low speed because while the motor is idling the fan is running flat out.
Most V8's require approximately 2000 cfm (cubic feet per minute). If you keep this in mind when you are buying thermo fans you will not waste your money.
In the Aussie Desert Cooler range, the 16" thermo pumps out 2800 cfm, our 14" pumps 2000 cfm, and our 12" pumps 1000 cfm.
So, if you cannot fit a 16" thermo, we recommend two of our 1000cfm 12" fans - this gives you 2000 cfm in total - adequate for most V8's!
Most timing is usually set up at less than 12 degrees static. In an attempt to gain more power, some will crank the timing over 12 degrees. This causes the explosion in the cylinder to occur when the piston is way down in the cylinder - heating up more area creates more heat. Cranking up the timing is fine in a race situation but for cruising you might be causing yourself problems.
If you are still in trouble, Contact Us. We don't charge for advice.