Importance of a thermostat in a 2L naturally aspirated engin

[Froon]

Well, I finally managed to locate a thermostat to fit to my runner today, after scratching my head for a while in regards to performance problems from the thing.

I fitted the thermostat to the car and noticed near immediate results. The engine itself never seemed to reach proper operating temperature, even on hot days and, after fitting the missing thermostat to the car, I noticed a noticable power increase in the engine.

Now I'm curious, is there any reason why someone would remove this from the engine? It seems like a fairly important thing to be removing.

My mechanic suggested I fit the thermostat for the following reasons:

1. It helps the car reach its proper running temperature.
2. It assists in cooling the car by restricting the rate of flow of the coolant, giving it time to cool once it hits the radiator.

The car itself is running 20-40 degrees warmer than I've ever seen it run (except on stockton) and does it in no time at all. whereas its previous running temperature was something that it took a long while to achieve.

[Micky-Lux]

What I've often seen, is that without the thermostat, the temperature displayed on the guage is cooler. At the same time, the actual temperature of the cylinder head is somewhat higher than what would be with the thermostat fitted.

The reasoning behind this is that with the restriction due to the thermostat, the water flows slower, allowing more heat transfer to the coolant. The result is hotter coolant, but cooler engine.

Sometimes people like to remove a thermostat to "mask" other problems, like stuffed thermostat, stuffed radiator, or other problems that may cause overheating.

[Froon]

Thats pretty much what I've seen, thanks for the confirmation.

[dumbdunce]

it is essential on that motor because it is a bypass type thermostat; when the main valve opens, it CLOSES the bypass circuit, forching the coolant through the radiator. without the thermostat, the bypass is open all the time, and the coolant will tends to curculate through the bypass and (it's not rocket science) BYPASS the radiator, getting hotter and hotter.