Words by Adrian Paton
Pictures by Jim Skouras and Dean Summers

Whether you have a stock S15 that you rarely drive, or a wild custom drag car producing a million kilowatts, one thing is certain, your radiator needs to be your best friend.

Radiators have been around pretty much since the beginning of the automobile era. Since and internal combustion engine can quite easily produce enough heat to wipe itself out, heat dissipation has been at the forefront of engine designers minds for quite some time.

The first radiators were simple devices with round copper tubes and water flowing through them by convection. By the 1920’s oval tubes were employed because they were slightly more efficient. As engines produces more power and consequently got hotter car manufacturers started to add fans to circulate a constant supply of air over the radiator cores. Some manufacturers added water pumps to push the water through for extra cooling effect.

Eventually larger tubes were experimented with but they required thicker walls to prevent the brass or copper bending under pressure. The upside to this was a more efficient radiator but the down side was the extra weight and size of the radiators. Thus manufacturers in this day and age have started to move towards aluminium radiators in production cars.

Aluminium Radiators:

Some of you might be wondering what’s the big deal with aluminium radiators? Why bother with them? Are they really worth the extra coin? Aluminium radiators are the high performance sport models of radiators. This means that high performance sports cars, drag cars and drift cars will benefit from using them. But then again such race cars will obviously have a bigger budget and cost won’t be such an issue. For the regular Joe with a street car, can the costs be justified?

The biggest attraction of these contraptions is their Herculean ability to keep things cool. Copper is actually slightly better for cooling but the weight and size to achieve the same amount of cooling makes it a difficult proposition. A high quality aluminium radiator will provide 20-30% more cooling capacity than an equivalent traditional style radiator. So if your car is producing 20-30% more power, it might be good to consider, especially if room is an issue in the engine bay. Boosted street cars will also benefit greatly from the quality cooling ability of an aluminium radiator.

Aluminium radiators also are lighter in weight when compared to a conventional brass, copper or steel radiators. With up to 40% of weight shaved off the front, it is no wonder many race cars are fitted with aluminium radiators. Aluminium is great for transferring heat and this means that you can also flow more coolant through it with bigger tubes.

Better cooling can be had with wider tubes. Wider tubes increases the ‘tube to fin’ contact area which has a profound effect on the radiator efficiency. This plays right into the hands of aluminium radiators as wider tubes with copper or steel will jack the weight a radiator right up into the Fat Joe echelon.
For a boosted high powered car with race aspirations an alloy radiator is a great option and looks sexy too.

Radiator Myths

1. Small leak equals no big deal. This small leak is like that sniffle that turns into pneumonia if left unchecked. This leak will probably be indicative of a larger issue at hand. The leak will mean that the coolant level will drop too low making it less efficient. This is something you don’t want as you can cause some damage to your cooling system if the coolant level is too low.
2. You don’t want too much coolant flow. This radiator myth has been around for some time and is still hanging about. Too little flow is obviously detrimental, but at normal and high operating temperatures, the rate at which coolant moves through the radiator does not change the amount of heat that is dissipated by the cooling cores. Sure, the mean temperature of the coolant will rise if it flows faster, but the amount of cooling will not be reduced.
3. Any old coolant will do. The cheap shit you buy at the local auto shop will not have the same additives of name brand coolants. Many do not have the corrosion protection, PH balancing, or sediment prevention that the top gear has.
4. Slow the engine down when overheating in traffic. Actually, revving your engine slightly when you are overheating in traffic will help push more air across the cooling cores and pushes more extra coolant through the engine, helping your engine stay cooler.
5. One radiator cap is as good as another. If you get a bad radiator car it will not last as long or stay properly calibrated, and will open at too low or two high a pressure. Ensuring yours is the proper one for the cooling system is important.
6. Bugs wreck your radiator. You would really need to drive through a locust swarm for any significant impact on the effect of your cooling. If you have a bug problem, with a shitload of bugs covering your radiator, use a pressure washer to clean it.

Any serious horsepower vehicle needs an aftermarket radiator such as this.