A Stupid Question
 

I've been around diesels most of my life between farming and driving trucks, both big and small. For some reason it just dawned on me this morning, my tractor doesn't have any glow plugs or grid heater that I have ever come across, so how does it start and run on these cold mornings. Just never paid any attention before, I guess.

my 50 ferg. has a fuel heater on it. follow your fuel lines and see if it tees off and goes to heater. i had to plug mine off because it was allowing fuel to get in my oil

Nope, nothin. I've had the whole fuel system pulled off the tractor in the past and no heat source at all unless it's inside the block. Don't know why I didn't think about it then but it never crossed my mind at the time.

It has a plug in block heater but that's it. No ether ever used and starts within the first few cranks every time, no matter how cold and I rarely plug it in.

mine starts pretty good without the heater hooked up. i have seen a few old diesels with a button you pushed. when you track down what the button does you find a can of either lol

I've worked with diesels that had no electrical system what so ever. Hydraulic units, pumps, winches and genorators (diesel end had no electrics). They where hydraulicly started. Really sucked when you screwed up the starting sequence and ran them out of pressure, had to hand pump a big ass accumulator back up to 3000psi. We ran them in sub 20F degrees. They would start right up.

Not a stupid question at all. I would say a logical one.
The german military also uses Diethyl ether. It has a high cetane number of 85 - 96 and is used as a starting fluid for diesel and gasoline engines because of its high volatility and low autoignition temperature. For the same reason it is also used as a component of the fuel mixture for carbureted compression ignition model engines. It is called "start-pilot". It is the only start system which is available with an permanent mount for the spray can.
It is also used in semis travelling constantly to norway.

One major disadvantage should be mentioned. Due to the fact it is an aerosol it washes down the oil on the cylinder wall. This causes wear.

Knowing that system from several extreme cold weather exercises, I can tell you the engine will start as long as you can provide cranking power.

Our work trucks have no heating systems other than the block heaters and most dont even get plugged in