vadym

The other day i took out my thermostat, and my car felt a lil faster and it was a lil louder. My temp. guage nidle was right in between cold and hot. I was wouldering if i can keep driving like this. And do All Drag and Racing Rx7s use thermostats in their cars?

NZConvertible

Removing your themostat will not make your car faster or louder. There's no way it possibly could.
Apart from taking ages for the car to warm up, the problem with running without a thermostat is the water circulates much faser (less restriction) so it actually picks up less heat. It reduces the effectiveness of your cooling system. There may be sufficient capacity in the system that that this will be OK on a stock motor, but not in a worked motor generating more heat than normal.
This applies to all motors, rotaries are no different.

RX-7Impreza

well, not neccessarily true. it isnt better for the motor, but coolant will pick up the same amount of heat no matter how fast it moves. now there is the question of how well it releases it. that probably wouldnt be as efficient. i am tired and trying to do physics in my head so dont be offended if i am wrong

justin

NZConvertible

Heat takes a finite amount of time to be transfered, it's not instanteneous. There will always be an ideal speed to pass a fluid over a hot body for maximum heat transfer. Too slow and the water isn't being removed as fast as the heat can be tranfered into it, too fast and the water is removed before it has absorbed all the heat it can. Either way means less heat removed. The same theory applies in the radiator, but in reverse.

RX-7Impreza

but think, there will always be water contacting the metal, so any heat one particle doesnt pick up, the next one will

Justin

2DoritosOnAStick

That's what I was thinking.

NZConvertible

Like I said, it's the time this takes that's important. This is a proven thermodynamic principle, not just my opinion.

Mobius

Yes NZ is correct. Ever done logrithms? Take newtons LAW of cooling for an example.

scathcart

Yes, this is true. This is why if you run your water pump too fast, you won't cool any better. This is why if you run an tuned electric pump which coolant circulates at the optimum speed regardless of engine speed, you will cool better. Try stick your hand in a bath of boiling water instantly. Then try sticking your hand in instanyly. Heat takes time to transfer. If not, adding a thermostat to any system, and the thermostat would immediately be correct. Newton's Law of Thermodynamics.
Sean

Gene

iTrader: (1)

Here is something to ponder. When a hot thing (let's say, your skin) and a cold thing (air on a chilly day) come in contact, heat is transferred. When the heat is transferred, the differential of temperatures between the two is reduced, and the transfer gets slower. However, if you replace the air with new cold air (wind) the transfer gets faster, hence the famous "wind chill." If you stuck your hand into the hot water and then back out, yes you would not be burned (badly anyway, it might turn red) however this is a poor analogy to the engine situation, because there is always new water to replace the old water, which is not the case in the hand-sticking. A better analogy would be to stick your hand into a STREAM of hot water, and you would find yourself injured in short order. Here's another one, fill up a nice hot bath, and go soak in it. (ahhhh just saying that makes me want to go do it) Sit very still for a while, and get used to it. Now, move your arms and legs a bit. Holy ****! It's hot all of a sudden! The water closest to you gave up some of its heat, and the water in the rest of the tub did not (not the the same degree anyway) it didn't get to move and mix much while you were sitting still, except by convective forces, but now you're stirring it up.

However, there still good reasons to use the thermostat...

1. Takes forever to warm up without it
2. May never actually GET warmed up, which is bad for your motor
3. Less consistent engine temps resulting in stress from increase and decrease of temp under varied conditions

The reason a constant-speed electric pump is good is because at lower rpm's it can flow more water than the engine usually would, and at high engine speeds it does not flow so fast as to cause cavitation, which lowers pump efficiency and can damage the pump's internal surfaces