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THERMAL PROPERTIES Water has amazingly superior heat transfer properties compared to virtually any other liquid cooling medium - far superior to glycol-based coolants. As shown in Table 1, water has almost 2.5 times greater thermal conductivity compared to glycol coolants. Mixtures of glycol and water have nearly proportional improvement due to the addition of water. Most heat is transferred in a cooling system by convection from hot metal to a cooler liquid as in the engine block or from a hot liquid to cooler metal surfaces, as in the radiator. The convection coefficient of liquids in a tube is a complicated relationship between the thermal conductivity, viscosity of the liquid, and the tube diameter which determines the amount of turbulent flow. Since 50/50 glycol solution has about 4 times the viscosity and only 70% of the thermal conductivity of water, the thermal convection coefficient for a 50/50 glycol solution is approximately 50% of the coefficient for water. Water in the cooling system is capable of transferring twice as much heat out of the same system as compared to a 50/50 glycol coolant and water solution. In order for a 50/50 glycol mixture to reject as much heat as water (amount of heat rejected is independent of the coolant), the temperature differentials at the heat transfer surface must be twice as great, which means higher cylinder head temperatures.
HEAT TRANSFER Red Line WaterWetter® can reduce cooling system temperatures compared to glycol solutions and even plain water. Water has excellent heat transfer properties in its liquid state, but very high surface tension makes it difficult to release water vapor from the metal surface. Under heavy load conditions, much of the heat in the cylinder head is transferred by localized boiling at hot spots, even though the bulk of the cooling solution is below the boiling point. Red Line's unique WaterWetter® reduces the surface tension of water by a factor of two, which means that much smaller vapor bubbles will be formed. Vapor bubbles on the metal surface create an insulating layer which impedes heat transfer. Releasing these vapor bubbles from the metal surface can improve the heat transfer properties in this localized boiling region by as much as 15% as shown in Figure 2. This figure demonstrates the removal of heat from an aluminum bar at 304°F by quenching the bar in different coolants at 214°F under 15 psi pressure. Compare the time required to reduce the temperature of the aluminum to 250°F, or the boiling point of water at 15 psi. WaterWetter® required 3.2 seconds, water alone 3.7 sec, 50/50 glycol in water required 10.2 sec, and 100% glycol required 21 sec. Water alone required 15% longer, 50/50 glycol 220% longer, and 100% glycol required 550% longer.
DYNO TEST RESULTS Dynomometer tests performed by Malcolm Garrett Racing Engines showed significant improvements in coolant temperatures using WaterWetter. These tests were performed with a Chevrolet 350 V-8 with a cast iron block and aluminum cylinder heads. The thermostat temperature was 160°F. The engine operated at 7200 rpm for three hours and the stabilized cooling system temperature was recorded and tabulated below: These numbers are similar to the temperatures recorded in track use and heavy-duty street use.
COOLANT EFFECTS ON PERFORMANCE
Under
moderate load conditions, each percent glycol raises cylinder head
temperatures by 1°F. 50% glycol raises head temperatures by 45°F. This
increase in temperature will raise the octane required for trace knock
levels by typically 3.5 octane numbers. A car equipped with a knock
sensor will retard the timing to compensate for the increase in octane
requirement by approximately 5°, which will reduce the maximum brake
torque by about 2.1%. Racing vehicles not equipped with knock sensors
can advance timing for increased torque. BOILING POINT ELEVATION Red Line WaterWetter® does not significantly increase the boiling point of water; however, increasing pressure will raise the boiling point. The boiling point of water treated with Red Line using a 15 psi cap is 250°F compared to 265°F at 15 psi for 50% glycol. Increasing the pressure by 50% to 23 psi will increase the boiling point of water to 265°F. Because of the doubling of the ability of the radiator to transfer heat, boilover using Red Line treated water is not a problem as long as the engine is circulating coolant through the head and the fan is circulating air. Sudden shutdown after very hard driving may cause boilover.
FREEZING POINT DEPRESSION Red Line WaterWetter® does not significantly reduce the freezing point of water. If the vehicle will see freezing temperatures, an antifreeze must be used. Water expands approximately 9% upon freezing which can cause severe engine damage. Even in summertime, the use of air-conditioning can blow freezing air through the heater and cause freezing of the heater core unless approximately 20% antifreeze is used. CORROSION PROTECTION Modern automotive engines now use aluminum for heads, radiators, water pump housings, and nearly all hose fittings. These engines require significantly greater corrosion protection than their cast iron counterparts of the past. Aluminum is such an electroactive metal that it requires an impenetrable corrosion inhibitor film to prevent rapid corrosion. Acid neutralization capability is very important. Coolant which has been left in a cooling system for several years has probably become acidic from the oxidation of the glycol to acids. Also, keeping the glycol concentration in the cooling system below 50% will help stability. Red Line also provides excellent protection from cavitation erosion in the water pump and cylinder head. Localized boiling in the cylinder head forms vapor bubbles which collapse when they come in contact with cooler liquids. This collapse creates tremendous shock waves which removes the inhibitor film from the aluminum surface and can cause catastrophic erosion of the aluminum if the inhibitor does not reform the film quickly. Another problem created by cavitation erosion is the deposition of the removed aluminum as a salt with poor heat transfer properties in the lower temperature radiator tubes. Red Line prevents this corrosion through effective film formation and smaller vapor bubble formation, which has a less violent collapse. Foam control is equally important since entrained air will cause cavitation erosion due to the collapse of foam bubbles. Red Line provides excellent control of foam with water alone and glycol solutions. Most coolants additives on the market provide only protection for iron and perhaps moderate protection for aluminum. The milky soluble oil types can actually impede heat transfer by wetting the metal surface with oil and this oil can swell and soften rubber coolant hoses. Table 3 shows the many tests which the Red Line formula will satisfy and how it compares to a standard antifreeze.
SLIPPERINESS OF COOLANTS Red Line WaterWetter® does not alter the frictional property of tire rubber and water on a pavement surface. The chart below shows the static and dynamic friction of pavement wetted with different coolant types. Higher friction indicates less slipperiness. The dynamic friction indicates the increase in slipping which occurs after the tire begins to break loose. Water and water with WaterWetter® reduce the friction relative to dry pavement about 50%, but it is much less than the reduction in friction caused by ethylene glycol and even more slippery is propylene glycol.
USE DIRECTIONS One 12 ounce bottle treats 12-16 quarts of water or a 50% ethylene or propylene glycol solution. In smaller cooling systems, use 4-5 caps per quart. Add directly through the cooling system fill cap into the radiator or into the overflow tank. Do not open a cooling system while hot. For best protection for aluminum, replenish or replace every 15,000 miles. The anti-scaling ingredients in Red Line WaterWetter allow its use with ordinary tap water. However, using with distilled or deionized water will accomplish some scale removal in the cylinder head area. For maximum temperature reductions use the most water and the least antifreeze possible to prevent freezing in your climate. Even in summertime the use of air-conditioning can blow freezing air through the heater and cause freezing of the heater core unless approximately 20% antifreeze is used. Red Line WaterWetter is available in 12 ounce containers.
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