Just a quick thought...
I'm not sure where in the flushing procedure it is ever indicated to 'leave the radiator cap off'. I read a comment about 'not building too much pressure' and I'd like to say that the coolant system is designed to be pressurized. Operating temps in most water cooled engines are between 190-195 degrees, given perfect conditions. The variables of changing riding conditions, fast, slow, in traffic, etc. and climate/road conditions means that coolant temps can rise past the point of becoming steam (I think I remember from my Physics class that water boils at 212 degrees at sea level.) I understand the boiling point of water will increase 3 degress for evey 1 pound of pressure in a pressurized system. Most coolant systems are designed to operate between 13-17 pounds of pressure thus increasing the boiling point of the coolant in the system by 39 to 51 degrees. This little fact of physics lets us do a lot of things with our engines we couldn't do otherwise.
Unless the flushing technique for changing coolant includes an open system where a constant supply of fresh water is pumped through the system, I would want to keep the system closed and allow the engine operating temperature to reach normal. If this open technique is used, water most be distilled and not tap, but I think most who would attempt this would know this.
It also seems that if the engine were allowed to reach and operate at normal temperatures in a closed (normal) system each time the system was rinsed out, this would achieve a higher efficiency in removing all traces of old coolant. PITA, I know, to keep doing this until the system is completely flushed, and then there's the fact it would take a lot of distilled water to keep the technique right.
I know there are a ton of other little stats that go into this procedure but I would want to be real cautious about running the engine with an unpressurized coolant system thinking that water would become steam much sooner and the procedure would become more dangerous. Anyway, just my .02!
I'm not sure where in the flushing procedure it is ever indicated to 'leave the radiator cap off'. I read a comment about 'not building too much pressure' and I'd like to say that the coolant system is designed to be pressurized. Operating temps in most water cooled engines are between 190-195 degrees, given perfect conditions. The variables of changing riding conditions, fast, slow, in traffic, etc. and climate/road conditions means that coolant temps can rise past the point of becoming steam (I think I remember from my Physics class that water boils at 212 degrees at sea level.) I understand the boiling point of water will increase 3 degress for evey 1 pound of pressure in a pressurized system. Most coolant systems are designed to operate between 13-17 pounds of pressure thus increasing the boiling point of the coolant in the system by 39 to 51 degrees. This little fact of physics lets us do a lot of things with our engines we couldn't do otherwise.
Unless the flushing technique for changing coolant includes an open system where a constant supply of fresh water is pumped through the system, I would want to keep the system closed and allow the engine operating temperature to reach normal. If this open technique is used, water most be distilled and not tap, but I think most who would attempt this would know this.
It also seems that if the engine were allowed to reach and operate at normal temperatures in a closed (normal) system each time the system was rinsed out, this would achieve a higher efficiency in removing all traces of old coolant. PITA, I know, to keep doing this until the system is completely flushed, and then there's the fact it would take a lot of distilled water to keep the technique right.
I know there are a ton of other little stats that go into this procedure but I would want to be real cautious about running the engine with an unpressurized coolant system thinking that water would become steam much sooner and the procedure would become more dangerous. Anyway, just my .02!
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