has anyone tried making an intake heater?

[JackMcCornack]

I sealed off my engine compartment and put the air intake in side with the engine, it's good for +75 degrees F (my car is a turbo diesel so YMMV). I believe preheating the intake air improves fuel economy, as I believe cooling the intake air improves horsepower. Economy is about maximizing the energy recovery from the fuel, horsepower is about maximizing the energy recovery from the oxidizer. Since when shooting for max horsepower one can easily add fuel to the system, the limit on horsepower comes from running out of oxygen. When shooting for max mileage, you're not running full throttle anyway so you aren't limited by air density.

[cRiPpLe_rOoStEr]

Originally Posted by kach22i

Correct me if I'm wrong, but with gasoline engines the idea is to preheat the fuel for easier ignition, and to chill the air to make it more dense.

Pre-heat the fuel is more usual in few flexfuel cars. I've never seen a pure gasser with this feature. It's a stock feature in some versions of the Volkswagen Polo made in Brazil and the Peugeot 308 made in Argentina, since Brazilian ethanol doesn't have the gasoline blend to ease the cold starts.

[oil pan 4]

Originally Posted by JackMcCornack

I sealed off my engine compartment and put the air intake in side with the engine, it's good for +75 degrees F (my car is a turbo diesel so YMMV).

Did you test it?
Diesels tend to lose power and fuel economy with warm air intakes.

Diesels seem to like their air intake temperatures at the manifold between 30F to 120F.
Below 30F and it seems to delay fuel ignition and above 120 and you cant pack enough air into the cylinders.

Every +1 degree C or F increase in intake temperatuers increases EGTs by that amount, so you are running 75 degree higher EGTs than nessary for no reason.

[RobertISaar]

i can't speak for diesel in particular, but with a gasoline enigne, a hotter intake charge is the way to go for fuel economy.

hotter air is less dense, which provides a couple of benefits, mostly being the reduced pumping losses due to having to open the throttle more to achieve the same cylinder airmass and a less dense air charge providing less resistance to movement. hotter air, i would assume also helps gasoline vaporization.

[oil pan 4]

Hot air provides not benifet to diesels, unless its really cold out.
The different processes at work between the gas and diesel engines are very different.

[cRiPpLe_rOoStEr]

Originally Posted by oil pan 4

Hot air provides not benifet to diesels, unless its really cold out.

Only in extreme cases some intake heating is desirable with a Diesel, like the grid-heater used in Cummins engines.

[Jakins]

I have my intake pipe touching one of my I take hose taking air from the radiator. I don't have any hard mumbers but it seems like it works. I've heard of pre heating gas. It seems like a potentially good way to get huge milage. Obviously it's kind of dangerous and you may be taking a risk by doing it but I want to find a way. Maybe by running the fuel line near the exhaust or coolant lines.

[mugen]

I have found that because ECO modding is somewhat new on the car scene. And because the US car scene has really always been about bigger louder faster is better. There is quite a bit of mis-imformation out there. For so long all "tuners" and "gear heads" were only interested in power and speed. This shaped most if not all of car modifications and tunning concepts. It can be hard to find good ECO modding information out there. So i can understand the hot air vs cold air debates ect...

[rmay635703]

Originally Posted by cRiPpLe_rOoStEr

Pre-heat the fuel is more usual in few flexfuel cars. I've never seen a pure gasser with this feature. It's a stock feature in some versions of the Volkswagen Polo made in Brazil and the Peugeot 308 made in Argentina, since Brazilian ethanol doesn't have the gasoline blend to ease the cold starts.

Oddly I ran one test on my cobalt where I heated the fuel tank up to about 150 degrees (average temp was probably only 100-120) when it was very cold out. The results I got where quite impressive, my engine temperature climbed to 110 in about 1 minute when it normally takes a while to get there, my fe was also much higher per the lie o meter.

It impressed me enough that I would like to locate a well controlled heating system (as oppossed to a magnet I have to watch like a hauk with the infa red)

Cheers
Ryan

[oil pan 4]

Originally Posted by mugen

So i can understand the hot air vs cold air debates ect...

There is no debate.
Most people don't understand how fundamentally different gas and diesel engines are.
Diesels need cool air (not bitterly cold air) for better milage, gas engines usually need warm or hot air for better milage.
Simple thermodynamics lays it all out for us.
Factory manuals spell it out for the no so thermodymanicly inclined, cummins has recommendations that their engines draw air from out side the engine enclosure in all but the coldest climates "for the best fuel economy and performance".