Engine temperature question: optimal engine temp

Hello all,

Was at the track yesterday and it started pouring, put tape on the radiator to keep the water warmer but it brought a question into my mind. Why is there a optimal temperature, I know it the water can obviously get too hot, however wouldn’t colder water benefit the engine more? This is something I’ve thought of and I apologize if it’s kind of a dumb question but why is it better for the engine to have a temp of 130ish rather than 110, how and why would it perform better? It’s something I thought of and couldn’t quite figure out and it’s kind of been bugging me.

Thank you

Distortion and clearances mostly. Too high and the distortion is too great.

Meaning cylinder and piston distortion?

I think it is more Cylinder and Crank Rod Distortion. Remember Metal expands and contracts with temp. Too cold and the cylinder diameter shrinks and you stick a piston. Too hot and it expands and you lose sealing at the ring. Too cold and the rod is shorter losing compression. Too hot and the rod is longer decreasing you squish gap and piston comes in contact with the head. I think 130 degrees F is just the sweet spot where everything works like it is supposed to. Also, different parts heat up and cool at different rates. That’s one of the reasons its a good idea to warm your engine on the stand before you go out and start putting additional loads on it.


I got it, makes sense!

Indirectly related. Years ago I rebuilt a straight six in a Jeep CJ-7. The front cylinder was closest to the water pump and got the cooles water. It ran coolest of the 6 cylinders. I as a result wore the most. It would lose more gas to condensation and as a result washed down the cylinder wall. I think mostly the main reason cooler is bad is because it is outside the paremeters that they optimized the design for. Often resulting in increased wear.

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