Engine insulation to conserve heat.

[krrcan]

I couldn't find any wiki post on this.

I'm by no means a expert, but as far as I have understod it, the engine is a heat engine, that excerts work based on differance of heat.

Would it be possible to gain efficiency, by insulating the engine (and/or engine compartment), and using colder intake of air, to get a higher differance between the hottest and coldest?

[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.

[krrcan]

I see.
Reality allways presents obstacles!

Are there any other advantages to insulating the engine and/or compartment? I saw someone doing this with fire blankets in a thread.

Is this solely a practice for winter in cold areas, to have a easier time to maintain the engine at optimum temperature?

[WD40]

It doesn't hurt in the colder months, biggest benefit is if you do a lot of small trips the engine stays hotter, less pollution and gas wasted on cold starts.

[some_other_dave]

The faster the engine gets into its "operating range" of temperature, the better. Warming up all of the engine parts and fluids costs energy, and whatever of that energy is lost to the surrounding air is simply thrown away. At least, until you get into the range of temperature that you wish to maintain--then losing heat to the surrounding air is generally required to keep the engine and fluids from getting too hot.

We have several people on the site who have insulated their engine compartment for that reason. It seems most useful in the winter, when warm-up takes the longest.

Didn't Frank Lee put some foam blocks across the top of his engine?

-soD

[B440]

I would consider insulating the engine compartment more, like some have done here, but I leave my vehicle outside so I would have another problem with rodents trying to move in every change of season. I have already had to remove the factory hood liner, and there are acorns in the hood supports that I cannot remove

[RedDevil]

The biggest benefit of insulating the engine is not faster warm-up time but retaining the heat until the next start. You get a head start, so to say.
My engine bay is pretty much closed off as standard, and my full grill block adds to that. The engine heats the air around it, but that can hardly escape.
Just blocking the seams of the hood lid woud do a lot. Mine have OEM rubber sealing.

So when I restart my car within 4 hours or so the engine is still warm. Even after a full day at work there is some residual warmth, maybe 5 to 10 degrees above ambient.

No worries about overheating the engine; the coolant and radiator keep that in check.

[Frank Lee]

Originally Posted by some_other_dave

Didn't Frank Lee put some foam blocks across the top of his engine?

-soD

http://ecomodder.com/forum/showthrea...-em-10529.html

http://ecomodder.com/forum/showthrea...tion-6052.html

Here's the latest one I made, for the T-Racer. It has "rolled" edges, that fold down where possible, to create more of a cap:

[cRiPpLe_rOoStEr]

In heavy-duty Diesel engines it's not unusual to have the valve cover and oil sump made out of composite materials, which provide some mild thermal insulation and noise suppression. Another good point is to wrap the exhaust manifold, directioning more of the exhaust heat to the cats.

[euromodder]

Originally Posted by some_other_dave

At least, until you get into the range of temperature that you wish to maintain--then losing heat to the surrounding air is generally required to keep the engine and fluids from getting too hot.

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.