Thanks!
I'm not sure I buy all of your explanation here. Water has one of the best capacities to absorb the heat of the engine and carry it away of any liquid. Adding the "anti-freeze" component definitely doesn't enhance that ability. Yes, the boiling point of a water solution is elevated by the mixture but the major issue is the pressure that moves the BP up into that 250 degree range. Although I have not tested this, I would assume that the efficiency of the radiator to get the heat out of the coolant is the main issue. Water wetter, if you believe its hype just breaks down (H2O)n into (H2O)smaller n or breaks up a lot of the surface tension making it in some magical way reduce hot spots. Now that I've spewed my BS, do you know of any tests of percentage anti-freeze to coolant temp with the thermostat wide open and a constant air flow to the radiator? It would be nice to see some science on those methylene glycol coolants too.
I'm not sure I buy all of your explanation here. Water has one of the best capacities to absorb the heat of the engine and carry it away of any liquid. Adding the "anti-freeze" component definitely doesn't enhance that ability. Yes, the boiling point of a water solution is elevated by the mixture but the major issue is the pressure that moves the BP up into that 250 degree range. Although I have not tested this, I would assume that the efficiency of the radiator to get the heat out of the coolant is the main issue. Water wetter, if you believe its hype just breaks down (H2O)n into (H2O)smaller n or breaks up a lot of the surface tension making it in some magical way reduce hot spots. Now that I've spewed my BS, do you know of any tests of percentage anti-freeze to coolant temp with the thermostat wide open and a constant air flow to the radiator? It would be nice to see some science on those methylene glycol coolants too.
I agree that the pressure gives a bit more capacity to the system than adding the ethylene glycol but both factors work in unison to provide the best cooling system capacity.
Pure water makes an excellent coolant for two reasons: it has a higher specific heat than ethylene glycol and it is less viscous so it moves thru the system faster. Trouble with plain water is that it provides no corrosion protection for the engine/cooling system and that it boils at a lower temp than 50/50 water/ethylene glycol.
Pressurizing the system to 15 PSI raises the boiling point to about 250 F if my memory is correct. Since there are spots inside the engine (particularily around the exhaust port walls) that are hotter than this the plain water can boil more easily at those local sites. The steam condenses rapidly within the normal flow of the system so the localized boiling isn't obvious but it causes the hot spots to get even hotter due to the isolating effect of the local boiling. Hot spots create high thermal gradients inside the engine which is not good for it's health. Trust me. Running the 50/50 mix raises the pressurized system boiling point to over 265 F which helps prevent localized boiling
How exactly do you get "smaller" H2O and what exactly is this mysterious "smaller" H2O......
The surface tension idea is the better guess. Water wetter claims to reduce the surface tension of the water. Ethylene glycol also reduces the surface tension of the coolant in the 50/50 mix so adding water wetter to 50/50 accomplishes nothing further. Adding it to plain water can help the cooling capacity a little but adding it to 50/50 has no additional effect so it isn't needed.....and/or, if you want the effect of water wetter just use 50/50 and get it that way.
I would entertain the arguement of plain water "making a better coolant" if the system were operating at maximum capacity and one were looking for a tiny bit of gain and the system had enough radiator to keep the temps below the 250 F range all the time. In that case the reduced viscosity of the water and the greater specific heat could give the system a tiny bit more capacity. But. The normal FJR cooling system is operating nowhere near full capacity when normaly riding down the road even with 4 bars showing. It is barely off the thermosat. So, given that the stat is still in play what gain could be realized by adding more capacity to the system??? NONE.
Track bikes and track cars run plain water because the sanctioning bodies require them to. It is a safety thing. In a wreck the plain water spilled just evaporates. Ethylene glycol is as slippery as oil and harder to clean up. Plus, ethyleneglycol is extremely flammible and can be a real hazard in a wreck when spewing on hot exhaust manifolds. Water won't burn. So, racers run water only because the rules require it. 50/50 would make a better cooling system for them as it would allow the system to run up past 265 F and stay under control with no boiling over.
Hot running cooling systems are actually more efficient. The greater the delta temperature between the heat exchanger and the air the more efficient it is. So, at max capacity, the system can actually handle more heat input (and reject more heat) running at 265 F (as allowed by the 50/50 mix) rahter then at 245 F (as plain water would allow.)
So, whether you buy it or not, there is a lot more to the cooling system than just the surface tension of the coolant and the specific heat and viscosity.
The other thing mentioned that is very important is the corrosion inhibitors in the 50/50 mix. The system of a street bike MUST be protected by corrosion inhibitors. Especially a bike with an all aluminum engine. The lack of corrosion inhibitors can cause serious engine damage...i.e..cracks in the cylinder head...in a street bike engine that rarely if ever show up on a track bike engine due to the time factor. You MUST run a corrosion inhibited coolant in the engine if you want it to live. Water wetter does NOT provide the corrosion protection needed.
To run the sort of tests you mention you would have to put the engine under heavy, continous load...something like climbing a 17 mile long grade in 100 degree weather towing a trailer or riding two up with lots of luggage, or both. Block the stat open to get it out of the picture. Then run the grade over and over with various concentrations of coolant. I think that you will find that the 50/50 mix of coolant provides the maximum cooling system performance due to the increased boiling point. The greater concentrations of ethylene glycol will cause an increasingly slight loss in heat carrying capacity but give a relativley large boost in the boiling point thus increasing the dynamic range of the cooling system. As the system gets furhter and further above 245 F it gets more and more efficient (due to the larger delta temperature between the radiator and the air rushing thru it) thus adding a considerable amount of cooling capacity...simply by preventing boiling. What slight loss in heat carrying capacity below 245 F that is due to the 50/50 mix is way offset by the positive gain in performance above 245 F.
No argument here....like he said!I agree that the pressure gives a bit more capacity to the system than adding the ethylene glycol but both factors work in unison to provide the best cooling system capacity.
Pure water makes an excellent coolant for two reasons: it has a higher specific heat than ethylene glycol and it is less viscous so it moves thru the system faster. Trouble with plain water is that it provides no corrosion protection for the engine/cooling system and that it boils at a lower temp than 50/50 water/ethylene glycol.
Pressurizing the system to 15 PSI raises the boiling point to about 250 F if my memory is correct. Since there are spots inside the engine (particularily around the exhaust port walls) that are hotter than this the plain water can boil more easily at those local sites. The steam condenses rapidly within the normal flow of the system so the localized boiling isn't obvious but it causes the hot spots to get even hotter due to the isolating effect of the local boiling. Hot spots create high thermal gradients inside the engine which is not good for it's health. Trust me. Running the 50/50 mix raises the pressurized system boiling point to over 265 F which helps prevent localized boiling
How exactly do you get "smaller" H2O and what exactly is this mysterious "smaller" H2O......
The surface tension idea is the better guess. Water wetter claims to reduce the surface tension of the water. Ethylene glycol also reduces the surface tension of the coolant in the 50/50 mix so adding water wetter to 50/50 accomplishes nothing further. Adding it to plain water can help the cooling capacity a little but adding it to 50/50 has no additional effect so it isn't needed.....and/or, if you want the effect of water wetter just use 50/50 and get it that way.
I would entertain the arguement of plain water "making a better coolant" if the system were operating at maximum capacity and one were looking for a tiny bit of gain and the system had enough radiator to keep the temps below the 250 F range all the time. In that case the reduced viscosity of the water and the greater specific heat could give the system a tiny bit more capacity. But. The normal FJR cooling system is operating nowhere near full capacity when normaly riding down the road even with 4 bars showing. It is barely off the thermosat. So, given that the stat is still in play what gain could be realized by adding more capacity to the system??? NONE.
Track bikes and track cars run plain water because the sanctioning bodies require them to. It is a safety thing. In a wreck the plain water spilled just evaporates. Ethylene glycol is as slippery as oil and harder to clean up. Plus, ethyleneglycol is extremely flammible and can be a real hazard in a wreck when spewing on hot exhaust manifolds. Water won't burn. So, racers run water only because the rules require it. 50/50 would make a better cooling system for them as it would allow the system to run up past 265 F and stay under control with no boiling over.
Hot running cooling systems are actually more efficient. The greater the delta temperature between the heat exchanger and the air the more efficient it is. So, at max capacity, the system can actually handle more heat input (and reject more heat) running at 265 F (as allowed by the 50/50 mix) rahter then at 245 F (as plain water would allow.)
So, whether you buy it or not, there is a lot more to the cooling system than just the surface tension of the coolant and the specific heat and viscosity.
The other thing mentioned that is very important is the corrosion inhibitors in the 50/50 mix. The system of a street bike MUST be protected by corrosion inhibitors. Especially a bike with an all aluminum engine. The lack of corrosion inhibitors can cause serious engine damage...i.e..cracks in the cylinder head...in a street bike engine that rarely if ever show up on a track bike engine due to the time factor. You MUST run a corrosion inhibited coolant in the engine if you want it to live. Water wetter does NOT provide the corrosion protection needed.
To run the sort of tests you mention you would have to put the engine under heavy, continous load...something like climbing a 17 mile long grade in 100 degree weather towing a trailer or riding two up with lots of luggage, or both. Block the stat open to get it out of the picture. Then run the grade over and over with various concentrations of coolant. I think that you will find that the 50/50 mix of coolant provides the maximum cooling system performance due to the increased boiling point. The greater concentrations of ethylene glycol will cause an increasingly slight loss in heat carrying capacity but give a relativley large boost in the boiling point thus increasing the dynamic range of the cooling system. As the system gets furhter and further above 245 F it gets more and more efficient (due to the larger delta temperature between the radiator and the air rushing thru it) thus adding a considerable amount of cooling capacity...simply by preventing boiling. What slight loss in heat carrying capacity below 245 F that is due to the 50/50 mix is way offset by the positive gain in performance above 245 F.
