Och

iTrader: (3)

That's why I'm not even going to bother, from the tone of your post I can sense that you'll just brush my points off.

SW17LS

So like I thought.

Och

iTrader: (3)

No, diesels never used carbs. Older diesels had indirect injection where fuel was injected into the so called precombustion chamber, instead of the main combustion chamber.

No Mike, this is where you seem to be confused and I will try to do my best to explain it to you. What you're describing is called preignition in petrol engines, where the fuel ignites before the end of compression stroke, causing detonation. I'm sure you're well aware of the factors that cause it, such as compression ratio, volatility of of petrol, octane number, ignition timing, operating temperature and perhaps most importantly air/fuel ratio. Lean out the mixture too much, and with so much oxygen in the mixture petrol will ignite well before the end of compression cycle where spark plug is meant to ignite the mixture. This can cause knocking, or in extreme causes it can even spin the crank backwards causing catastrophic engine damage. It is becoming less and less of an issue with modern direct injected engines, because fuel is delivered late into the compression stroke, and I believe in certain cases even early into the power stroke, which allows modern engines to run with very lean air to fuel ratios and high compression ratios, essentially making them more and more diesel like.

Preignition has never been an issue even with old indirect injection diesels because diesel fuel is not as volatile as petrol, and its a complete non issue with modern direct injected diesels. Preignition in a DI diesel can't occur, because only air is being compressed during compression cycle, and fuel is injected (under insanely high pressures 25-30,000psi) at TDC where it ignites. Thus you can lean out diesel AF ratio as much as you want, and the leaner the mixture the cleaner it burns. This is the primary reason why diesels are so economical, you can lean out the mixture completely during idle and during low load, where only tiny amount of fuel is delivered just enough to keep the engine turning itself, where in petrol engines AF ratio must be kept in a certain range.

Yes, and these high pressure injection systems are expensive to produce and maintain, very fragile, and extremely sensitive to any contamination and water. It can sometimes cost over $1,000 just to replace a single injector.

dicer

If you want economy diesel is the way to go. Higher heat value of the fuel, less pumping losses and greater expansion area, all mean more efficiency. And as far as mineral fuel burning engines go, diesel engines beat all the others. There are some diesel engines that approach and may exceed 50% efficiency which is really good as compared to all the rest.

And actually there are diesel engines that had carburetors on them.
I worked on one many years ago.
And this is exactly the same type of tractor I worked on.

Och

iTrader: (3)

Yes, but those are not true diesel engines, they are 2 stroke engines that can run on diesel and other fuels, and they require petrol to start and warm up before they can be switched to diesel. Once they switched to diesel, wasn't diesel injected?

dicer

Sorry but that tractor is NOT a 2 stroke, and it is true diesel with a carburetor. All diesel engines can run on other fuels, and some can burn straight automotive gasoline as well. And of course as a diesel fuel was injected. Oh and there was an induction throttled diesel as well, I'll leave it at that.

Och

iTrader: (3)

Well but diesel was injected, carb was only for petrol, so its really not a carbureted diesel.

dicer

Same engine no starting engine the carb is mounted on the engine so technically is it carbureted. And besides there are truly carbureted diesel engines.
As long as the definition of diesel engine is an internal combustion piston engine that will due to high cylinder air pressure ignite and burn diesel fuel. ???

Och

iTrader: (3)

Basically diesel engine is a compression combustion engine with no spark plugs. That said, there are no carbureted diesel engines, diesel fuel is too thick to be atomized by carburetor.