Steve Baur
Former Editor, Modified Mustangs & Fords
January 24, 2007
The Evans Cooling kit includes everything you need to keep your pony cool. The electric fan is available as an option. You can use your stock clutch fan, or ECS can supply you with either a single or dual-electric unit.

The ever-aging 5-liter Mustang suffers from many maladies, and one of the most important is cooling system degradation. Barely adequate for the stock engine, performance modifications can place a higher demand on an already taxed system. Add in the average age of the components and you have the perfect recipe for poor cooling.

Sit in any black Mustang GT that's idling in traffic during an average 95-degree summer day, and you can watch the temperature needle rise. AOD-equipped cars have it even worse because part of the radiator is used for transmission cooling.

The stock 5-liter cooling system also suffers from another problem. "Ford downsized the diameter of the radiator inlets on the Fox Mustang and this restricts the flow of the coolant and ultimately hurts the performance of the system," said Dave Wright of Evans Cooling Systems. "They actually went up a size when they went to the '94-95 models. Flow is everything when you're talking about performance applications."

Evan Cooling Systems (ECS) has advanced cooling components for all kinds of vehicles, including diesel trucks, race engines and street cars. The key component is its NPG coolant. NPG, which stands for non-aqueous propylene glycol, is a waterless coolant. Why is this important you ask? Well we're about to tell you.

We said goodbye to cracked clutch fans and cruddy radiators. This job is really simple if you have basic mechanical skills and tools. Heating the drain plugs will be the most difficult task, and if you don't feel comfortable with doing that or replacing the water pump, you might want to have a professional technician complete the job. We spent two days on the installation, but if you work straight through, it shouldn't take longer than four or five hours. We did ours in mid winter and the garage wasn't heated, so we took frequent breaks to let our hands thaw out.

The main thing to know about water is at a certain temperature, it turns to vapor. Water vapor doesn't absorb the heat from the metal surfaces that it is trying to cool (namely cylinder heads and walls), and this creates higher combustion temperatures, which can lead to detonation. Detonation is bad, very bad. Evans NPG and NPG+ coolants contain no water, so you never encounter a vapor-related overheating situation. They also have boiling points of 370 and 375 degrees respectively. This keeps the internal engine components cool and happy, even under higher than normal temperatures.

Water-based coolants use a higher system pressure in order to raise the boiling point of the coolant and while this is effective, it has its downside. Increased pressure means more strain on the individual components like hoses and gaskets. The high-boiling point of the NPG coolant allows it to run with little or no system pressure at all. At colder temperatures, water will freeze and expand, which is why engines are equipped with freeze-out plugs. Propylene glycol, on the other hand, shrinks and becomes a gel. NPG's waterless nature eliminates system corrosion and water pump cavitation, too.

NPG is ECS's original formula that was designed primarily for racing applications. NPG+ adds ethylene glycol to change the viscosity below 0 degrees Fahrenheit. Racers need to check with their local tracks, as some do not allow the use of ethylene-glycol coolants. If it's a strip only machine, chances are you're not worried about sub-zero performance anyway. The fact that the NPG coolant doesn't evaporate means you never have to add to it, and ECS claims their test vehicles with over 200,00 miles on them show no signs of chemical deterioration, which makes the system virtually maintenance free.

In addition to the NPG coolant, ECS also has complete cooling systems for vehicle-specific applications. These systems include a custom high-flow/high-capacity aluminum radiator, redesigned or modified water pump, ECS-specific thermostat, hoses and special clamps. Cooling fans are an option, as the user can choose between their factory unit or the high-performance pieces ECS sells.