![]() If you look at a phase change diagram for something like water (and generally water mixtures like most coolants) it looks like this Water is great for us humans and our need to control temperatures because it is extremely abundant (cheap) and it has a relatively great physical properties for heat transfer. The thing about boiling though is that it serves a purpose in the coolant as well. Creating a corrosive pitting scenario in those spots where liquid coolant is no longer protecting the surface You may avoid local hot spots where the vapor is forming on the metal surface if you do end up in a coolant boiling situation and avoid:Ģ. The main thing is it does not boil as readily as regular coolant or water wetter treated water does. It probably isn't the best option for everyone, but it does have benefits in certain circumstances. It serves a purpose that regular coolant may not fill for certain riders. So here's the deal with Evans as far as I've studied it. I have no idea whether Evans is better than Engine Ice or not, I'm just explaining some of the physics involved. You can't just simplify this down to a thermal conductivity argument.Ī good coolant has high thermal conductivity AND high thermal mass, a high boiling point, a low viscosity, and various other properties relating to heat transfer at the coolant/engine/radiator interface. And the thermal loads and heat transfer (in and out) of the system are very transient. The entire cooling system isn't a single temperature and it's not all flowing around at the same rate. If you have a material with a very high conductivity, but very low specific heat and/or very low density, then you'll raise temperature so quickly you'll lose cooling efficiency or possibly change phase (vaporize/boil). the volume of the cooling system on your bike) can absorb per degree increase in temperature. The density of the coolant, combined with specific heat, wil give you thermal mass, or how much energy a particular volume of coolant (e.g. ![]() Specific heat is the property representing how much heat energy is required to raise the temperature of a unit mass of coolant by one degree. But it's certainly not the only property of interest. And yes, it's rather important to the topic at hand. Thermal conductivity is a measure representing the resistance to heat transfer through the coolant. If you think of this as an overly simplified, one dimensional, and steady state problem, then yes. It's why I avoided using it for many years (plus the outrageous price it was here in OZ) But, it sure as hell does not run as hot as a boiled over, empty radiator-ed bike. So, after that novel - to repeat, you Can put water into your Evans, but, it just goes back to being a standard type coolant.Īnd, while it remains 'pure', it's high temp capabilities, can hide problems, and have the bike run very, very, Very hot. ![]() Fans on, it goes back to being a Big Old Teddy Bear of a bike. When it gets to that very, very hot state, it gets quite cantankerous. So, the Evans has saved me, when I've forgotten to turn the lights on, and, I notice the bike is getting very, very hot, but, at least it doesn't boil over. ![]() When I fitted a new, narrow switch block ( I run full lights and blinkers, to keep the cops off my back), somehow I messed up and now the fans don't work, be it on the thermal switch or the manual switch, unless the lights are on. I found Evans at a local store, for an affordable price. Plus, I finally fitted high capacity radiators. When I finally did a re-bore, I fitted a waterproof Spal fan (though, I'd only gone through 2 of the 'puter fans, due to dust / water), but retained one of the 'puter fans. Nothing really worked to entirely stop the boil over. I doubled up on catch tanks - KDX and WR ones at the rear, then a Gas Gas one that went around the steering head. Modified the impeller to have longer vanes, with a water pump spacer. Ported the various inlets and outlets of the coolant system, and the water pump. I made various inline aluminium coolers, through to (near) entire finned aluminium lines, that looped back, down then back up to the radiators, which added about 300ml to the coolant capacity, plus the extra 'radiant' capability. Various coolants ( including Engine Ice), other than Evans - as, I did Not want to 'hide' the problem, and have the engine 'cook in it's own juices' - and none, cured the 'kettling'. It's used as a single tracker, extreme terrain torque monster, so it doesn't get much airflow through the radiators. My 500 2T has been a 'kettle' since I've had it. So, in that state, it probably is a far lesser coolant than Engine Ice, and other high performance coolants. But, it no longer has the same properties.
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