Here is a link to some of the Gallery pics for Evans Cooling. It was even featured on "Shade Tree Mechanic".
http://www.evanscooling.com/main11.htm
Other technical considerations:
Boiling Point: 369° F for NPG versus 224° F for 50/50 "EGW" ethylene glycol and water (at atmospheric pressure - 0.0 psig) - benefits include elimination of afterboil and overheating, allowing temperature excursions above those for EGW, faster recondensation of vapor inside the engine, low (2.0 - 4.0 PSIG) or non-pressurized system, no coolant loss operating in high ambient temperatures, and the capability to increase thermostat temperature settings if desired.
Molar Heat of Vaporization: 12,500 Cals/Mole for NPG versus 9,720 Cals/Mole for EGW - benefits include faster recondensation because less vapor is produced, and a reduction of hot spots because of improved liquid to metal contact. All of which eliminate the occurrence of "Film Boiling" and the accumulation of excessive surface vapor.
Surface Tension: 35 Dynes/Cm for NPG versus 56 Dynes/Cm for EGW -- benefits include small vapor bubble sizes, allowing for faster recondensation of vapor and increased liquid to metal interface, and decreased area of nucleate boiling centers, again increasing liquid to metal interface.
Freezing Point: -70° F for NPG versus -38° F for EGW. NPG does not freeze, it crystallizes and supercools (contracts slightly and becomes a viscous slurry).
Toxicity: EGW is considered a hazardous waste whereas NPG is not as PG is used as a food additive and pharmaceutical base fluid.
Vapor Pressure: 590 mm of Hg for EGW at 212° F versus 18 mm of Hg for NPG. This is the major reason for the dramatic decrease in cylinder liner and pump cavitation.
Important Benefits of NPG Coolant:
Reduction of Hot Spots (Critical Metal Temperatures);
For Gasoline Engines:
Higher Gasoline Efficiency.
Reduces Emissions.
Higher Compression, Power.
Knock Reduction.
Improved Octane Tolerance (lower octane fuel useable).
Secondary Benefits of NPG Coolant:
For Gasoline Engines:
Non-pressurized: (or low pressure, i.e. 4.0 psig) decreased leaks, lower pressure parts, decrease of thermal flexing or cycling (component life extended), elimination of accidents resulting from accidental removal of radiator caps from hot engines.
Allows for a totally closed system (Hermetically Sealed) requiring no service checks and is not subject to contamination.
Improved stability of engine operating temperatures.
Improved aerodynamic styling. The radiator no longer needs to be higher than the engine and can be placed anywhere.
Weight reduction possible if higher coolant temperatures are used. Smaller radiators, less coolant, light-weight metals (such as magnesium for engines), small cooling jackets in the engine, smaller fans.
Decreased duty cycle of coolant fan for the same coolant temperature by allowing for higher temperature excursions for short intervals with no adverse effects on the engine.
Faster combustion chamber metal surface warm-up, CO reduced in start-up (liners get hot faster) mostly because of lower specific heat of cold NPG.
Elimination of premature spark plug failure and head cracking by better cooling of head.
Reduction or elimination of pre-ignition and detonation:
Reduce head distortion and cracking at high compression and supercharged / turbocharged boost levels.
Reduce head gasket fire ring failure.
Reduce piston dome and ring failure.
Reduce valve face sinking ("tuliping").
Reduce rod bearing failure (caused by cylinder pressure, detonation related, spikes).
Threaded Mode
