Engine insulation to conserve heat.

[Joggernot]

Originally Posted by ksa8907

Theoretically, yes but the problem is production engines are made to run around 200f and when you go much beyond that the pistons tighten up more than normal because of thermal expansion.

Now, if you hand build your own engine and design it to run hotter, sure you'll probably see a gain.

Run some numbers through the equation and you'll see you need a significant increae in temperature to realize a gain.

+1
I have done this on a 1982 Honda Accord (Wash DC area) and it worked as long as the engine didn't overheat. I have seen wrapped/insulated exhausts, and full engine insulations done with a thermostat set for 250°F + and new hoses(!). I don't know what pressure the radiator is designed for, so overheat/overpressure could be a problem there.

[B440]

This topic always reminds me of NASCAR.

"The smaller grille and pressure valve will require teams to keep their engines at or below 240 degrees. During last Saturday’s race, some drivers said they were running at nearly 300 degrees in the draft."

From here:
http://jacksonville.com/sports/racin...nt-grille-size

But their engines don't have to last as long as ours.

[ksa8907]

Improving aerodynamics is a much easier, safer, and effective means of increasing vehicle efficiency.

[RedDevil]

Insulating the engine has little to do with overheating the engine, but all with retaining heat while not in use. The radiator keeps the temperature in check, and if that fails having no insulation won't save the engine.
Just to be on the safe side: do not draft at a few inches at speeds around 200 MPH. That is a lot less safe than insulating the engine. Maybe NASCAR is not the best example for ecomodding.

The better the aero, the harder you will need to retain the heat. Last winter at -12°C I had a hard time getting my Insight warm within my 22 mile commute...

[Piwoslaw]

Originally Posted by euromodder

That's when you run into the basic design flaw of most current cars : the radiator is in the engine compartment. So in order to cool it, you have to let cold air into the engine compartment.
Or design a radiator duct that doesn't end up in the engine compartment.

Ah, but the heat which is taken off of the radiator is then blown back over the engine block. Maybe good for warmup times when your t-stat is stuck open, but not very efficient as a cooling system.

Putting something between the rad and engine that would shield the latter from air and heat wouldn't be a bad idea. Except that most engines rely on that airflow to cool alternator and/or oil.