I cannot give you a complete answer at this time, however I can tell you that Diesel fuel requires compression, and that it does not burn the way Gasoline does, rather it explodes when enough pressure is exerted on it (in the presence of a spark). In essence, the engines are completely different, although once you get past the combustion chambers and reach the crank shaft, the rest is very similar. Putting a small amount of gasoline into the diesel fuel will not terribly adversely affect the diesel engine. However, diesel in your gasoline can make your gas engine nearly inoperable.

In a gasoline engine, a mixture of gasoline and air, controlled by a throttle, is inducted into a cylinder. Some engines use aftermarket cold air intakes to gain horsepower, torque, and throttle response. This is compressed by a piston and at optimal point in the compression stroke, a spark plug creates an electrical spark that ignites the fuel. The combustion of the fuel results in the generation of heat, and the hot gases that are in the cylinder are then at a higher pressure than the fuel-air mixture and so drive the piston back down. These combustion gases are vented and the fuel-air mixture reintroduced to run a second stroke. The outward linear motion of the piston is ordinarily harnessed by a crankshaft to produce circular motion. Valves control the intake of air-fuel mixture and allow exhaust gases to exit at the appropriate times. A critically important portion of any internal-combustion engine is its ignition system, which controls the timing of the burning of the fuel mixture. If this burn begins either too early or too late the engine performance will be reduced, sometimes seriously, and in extreme cases can even damage the engine. The diesel engine is a compression ignition engine, in which the fuel is ignited by the high temperature of a compressed gas, rather than a separate source of energy (such as a spark plug). When a gas is compressed, its temperature rises (as stated in Charles' Law); a diesel engine uses this property to ignite the fuel. Air is drawn into the cylinder of a diesel engine and compressed by the rising piston, at a much higher compression ratio than for a spark-ignition engine. At the top of the piston stroke, diesel fuel is injected into the combustion chamber at high pressure, through an atomising nozzle, mixing with the hot, high-pressure air. The resulting mixture ignites and burns very rapidly. This contained explosion causes the gas in the chamber to expand, driving the piston down with considerable force and creating power in a vertical direction. The connecting rod transmits this motion to the crankshaft which is forced to turn, delivering rotary power at the output end of the crankshaft. Scavenging (pushing the exhausted gas-charge out of the cylinder, and drawing in a fresh draught of air) of the engine is done either by ports or valves.

Mechanically the two are very similar, sharing most significant design elements (block, crank, pistons, rings, oil bearings, heads, intake manifold, exhaust system... most large gas and diesel have valves and a cam shaft). Most automotive gas and diesel engines have a fuel pump and fuel injectors. Both can be designed as two-stroke or four-stroke. Some of the most significant differences: Diesels do not need an ignition system - no coil, distributor, or spark plugs - but instead depend on the heat of compression to burn fuel. Before the engine is hot, "glow plugs" can be used to start combustion, but they are not timed like spark, they just stay hot. Gas engines control power production with a throttle that reduces air pressure in the intake manifold so less air and fuel get into the cylinder. Diesels have no throttle (this gives them a small efficiency advantage), they control power by pumping less fuel into the cylinder. Gas engines add fuel to the air before it enters the cylinder, diesels spray it directly into the combustion chamber after compression - except small two-strokes. Fuel for a gas engine should have a very high ignition energy and quick burn to prevent "pre-ignition" - explosion before the spark fires - which causes knocking and can damage the engine. The fuel should burn on a "flame front" that travels through the fuel/air mixture, not explode. Fuel for a diesel should have a very low ignition point so it starts burning as soon as it contacts the hot air in the cylinder. Diesels run higher compression ratios - gas engines typically run about 7-10, diesels run over 14. The higher the compression ratio, the higher the thermodynamic efficiency of the engine, so diesels have another advantage here. You can't practically make a gas engine higher than about 12 because the mixture would get too hot and explode before the spark. Turbo- and super-charged gas engines typically use a lower compression ratio and higher fuel octane rating to allow higher compression temperature because the mixture is already compressed when it goes into the cylinder. Diesels are not limited in this way and usually have much higher turbo boost pressure than gas engines. Add to this the absence of a throttle and you can get a lot more air into a diesel cylinder than a gas cylinder, and get a lot more efficiency out. Because of the differences in how they operate, diesels are typically designed for lower RPM operation and higher low-end torque and are almost universally turbocharged in production cars and trucks. Gas engines (especially with smaller displacements) are typically designed for higher RPMs and get higher torque and horsepower by filling the cylinders more times each second. There are exceptions, but this is most common in mass-produced engines. Because of the higher compression and related issues, diesels typically require more frequent oil changes and a better grade of engine oil.

Also, I want to add that diesel, because the piston can go up higher, the compression ratio is higher So, in a diesel car, it has more low end torque, that is why you see it on big trucks.