??? About Thermostats in Race Bikes. Remove? yay or nay?

This make zero sense. Are you saying the cooling system is better at absorbing heat instead of release heat?

 

^ no, he's saying that the water doesn't stay in the radiator (where it cools off) long enough for it to actually cool off. thus, hot water keeps getting put into the engine so no cooling takes place.

 

Exactly. :up:

 

But then the water in the engine stays in there longer absorbing more heat that needs to be cooled off. Where does the equation lead to less heat in the water?

 

i don't buy into this theory..iv'e ran bikes in FL with no t-stat. i run a t-stat now as i have found the 08r6 does not run as well below 180f. Without a t-stat it was often below and the ecu messed with the a/f mix. Even with a t-stat i sometimes havr to run a strip or 2 of tape on the rad to keep the temp up on track.
once a bike is up to temp and the t-stat is open..thats it, it's open. By the above theory, a bikes coolant won't cool if constantly circulated..??

 

Someone will have to dig up a thermodynamics book to be sure, but while the higher flow rate does result in less temperature drop of the coolant as it passes through the radiator, the increased flow rate results in a net transfer of more heat energy away from the engine. Uh, I think, and all else being equal blah blah blah...

 

well, i think it's more complicated than people are making it, but i'm sure there's a reason. probably has to do with what water is where for what amount of time etc... water does not only stay in the jackets and the radiator, it can also be found in the pump, the hoses, the reservoir, etc.. and there must be some sort of balance that gets upset when it flows too fast.

it's not a theory. pgs. 1-2 of this thread chronicle that it's been proven (notably the post by Chip, where he confirms its validity in certain applications).

 

Are you serious. Like I said previously, this will not be the same in all applications. And, the thermostat does not stay open once the engine reaches temp. If your theory was correct then there is no need for a thermostat.

 

don't care what theory you want to apply.. ive been there-done that. same bike, without t-stat ran cooler, often too cool for my liking. On cool days it wouldn't heat the motor fast enough for my liking.

 

The thing is a thermostat will open up fully to have the designed amount of less resistance when the temp gets to a point where it needs cool the water down. Once the water has cooled down the thermostat will close slowly as the temp goes down thus providing less cooling. Motors don't like to run dead cold and without a thermostat your motor won't maintain the temp range it likes to run at...it'll simply run too cold in most situations.

If the bike is over heading...the problem isn't the thermostat...its somewhere else. Head gasket, too much compression for the radiator(s), busted radiator cap so it can't maintain pressure which raises the boiling point, etc.

Recently a friend of mine was having cooling issue at Fontana. He swore the problem was his thermostat was stuck and that was the problem. They swapped out the thermostat and it still over heated. When he got home it turned out the radiator cap was busted. Problem solved.

 

^ plus, even with the t-stat open, the water is not flowing as freely as it would with the complete absence of a thermostat (it is still restricted by the partial blockage of the tstat itself).

 

yea, that's one bike. others may differ.

 

A cooling system is a very simple design. But, there are many factors including, cooling system pressure, air temp, fairing design, pitch of the fan blades, etc. A thermostat only reads from one side. When the water on the engine side of the cooling system reaches temp than it opens and the "cool" water comes from the radiator into the engine. Even though it is a small change in temp on your gauge, it is enough for the thermostat to close back. Then the hot water in the radiator is cooled. And so on... I know I have over simplfied this but it is a basic principal.

 

I know...this is where my statement of "designed amount of less resistance" comes in.

Its all designed by a bunch of engineers who spend countless hours working this out. If you get out of range then either a) they messed up or b) you have a problem. I prefer to go with the simpliest answer of b.

 

the pieces you mentioned of "fairing design, pitch of the fan blades" is simply about the CFM of air flow at a particular air temp.

Are you trying to say your thermostate cycles that fast? really? right....have you seen how SLOW they open and close when tossed in boiling water and then thrown under cold water?

 

Are you trying to say your thermostate cycles that fast? really? right....have you seen how SLOW they open and close when tossed in boiling water and then thrown under cold water?[/QUOTE]

The key words you need to look at in my post was "cooling SYSTEM". I was simply stating there is more to a cooling system than just a tstat. And yes I have seen how fast they open and close. They move fairly slowly, I know. Wasnt trying to start a revolution, just stating FACTS.:up:

 

http://www.rscycles.com/tech_articles/Thereo_tech.htm
interesting read about the importance of a good t-stat and that most times expensive oversized rads are overkill, and the importance of slow changes in cooling (as cyclworks pointed out, probably why t-stats open slow).

 

It's CycleWorx. Get it right. J/K:up:

 

Mr. Sunshine, from the article that Melk-Man posted:

"The issue being that the water has to have sufficient time to absorb the heat that we are asking the water to carry away from the motor. If water flows to fast and there is little heat transfer we may overheat a motor."

in response to your question about the balance between heat picked up and dissipated by the water, time in the radiator vs. engine etc...

 

At the same time if you flow water through the radiator too fast it won't be able to dissipate the heat into the radiator and then out into the air. So it won't cool down and the next pass into the motor it'll not be able to get anymore heat and over heat the motor.

So all of this I understand....but problem is only one side of the equation is being talked about by ye'all so I'm trying to get you to explain the other side of the equation and show in some way that you know there is another side.