Don’t Fear the Temperature Gauge

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One of the questions most frequently asked of the Evans technical staff is, “How much cooler (or warmer) will my engine run with Evans?”

The answer: Most often, there will NOT be a noticeable change in the operating temperature.

Under normal conditions, a typical car driven daily with standard equipment running with Evans Coolant will operate in the same range as 50/50 (ethylene glycol/water) coolant. Although the boiling point of Evans is 375°F, that doesn’t mean it will reach higher operating temperatures. What it does mean is that Evans waterless coolant will remain a liquid, and maintain efficient heat transfer well past the point where water-based coolant will boil (aka its failure point).

However, all engines and cooling systems are not created the same, so the temperature reading may vary depending on the application, driving conditions, or cooling system modifications. If the coolant temperature becomes hotter after converting to Evans, we recommend a little investigating.

What to check if your coolant becomes hotter:

1. Be sure you have less than 3% water.

A higher water content lowers the boiling point (see graph at right) and excessive water may still allow for vapor formation.

2. Has the system cycled more than once and been bled properly?

Air pockets and low coolant level could cause the increase in temperature.

3. Does the level of the expansion tank change?

If not, this is an indicator the system is not full.

4. Has the weather changed since the conversion to Evans?  

Increased ambient air temperatures and/or the use of the A/C may increase the operating temperature, particularly in hot climates. If the increase is just a spike and the temperature returns to normal at highway speed there could be a problem with the thermostat opening properly or not closing the thermostat bypass completely.

If the vehicle is modified in any way to increase horsepower, a change of air flow, a replaced radiator, or any other cooling system modification, an increase may be observed. Also, restrictive passages may hinder coolant flow and show increased temperatures.

With Evans, operating at a slightly warmer isn’t always a cause for concern as it might be with a water-based coolant. Evans remains a liquid and can continue to pull the heat away from the engine without turning to vapor. Evans allows safe operation in a higher temperature range without fearing overheating, boil-over, and loss of coolant.

A few examples where temperatures may change:

A high performance muscle car or street rod with carbureted or fuel-injected engine running 220°F to 240°F before conversion to EWC, often uses aftermarket modifications and various parts designs. Some of these aftermarket parts may be restrictive, and not optimally designed for the use of EWC.

Some examples of restrictive components are:

  • Smaller restrictor washers
  • Steel braided radiator hoses with a smaller inside diameter than stock
  • Multiple pass radiators
  • “High efficiency” radiator cores with more rows of smaller tubes
  • Under drive coolant pumps
  • Certain electric pumps

If one or more of these components is used with EWC the cooling system temperature can increase. Relieving the restrictions allows increased flow capability and improves the heat rejection in the cooling system, where a decrease in operating temperature is possible.

If the gauge shows temps of 220° to 240° Evans can handle it without fear of over-boiling. EWC will control the internal combustion chamber temperatures and maintain normal power levels at those temperatures, but you’ll want to make sure other fluids are in their normal operating range and engine materials are capable of the increase in heat.

To lower a temperature to a more normal range, the first change that should be considered is changing or removing the thermostat. Next, an increase in pump speed will result in the best temperature the current components are capable of. If improvements in the air side of the system are possible, the radiator design is the best bang for the buck. Before making any hardware changes, we suggest calling Evans Tech line at 888-990-2665 to be sure the changes can accommodate EWC.

Engine Temperature in Older Cars

With classic/antique cars, where modification choices are limited, an increase in operating temp can possibly create problems with original type gauges that max out in the 212°F range. Evans can control the metal temperature and eliminate or reduce the boil-over problem by simply avoiding vapor.

Challenges with older cars include:

  • Engine component material not designed to withstand higher temperatures (such as valve springs and piston rings)
  • Gaskets designed to seal 100% water
  • Lubricating systems that do not have the capability to dissipate extra heat from the oil (putting greater demand on the cooling system)

The upside is that most of these systems were over-designed from the start, with larger radiators, better frontal opening, lower horsepower due to the cooling limitations of 100% water. These systems can be operated at the higher end of the temperature range if certain precautions are taken, or if during restoration, the components are updated to modern standards when possible, and exposure to the temperature is limited.

One more point on this application. These vehicles are rolling irreplaceable history. Those that believe in driving history as the best way to have it appreciated can justify the improvements required to preserve their passion, and know that 100% water is the enemy of this preservation.