Diesel to Gas
Is it possible to change a Diesel engine over to a car Gas engine? Would there be any advantage to doing that, like lasting a 1,000,000 miles.
You mean modify a diesel engine to run on gas? No. It would be easier to start from scratch.
How they operate is too different.
Read up on "Otto cycle" versus "Diesel cycle"
The fundamental difference between the two is a diesel runs on compression-ignition, gasoline runs on spark-ignition. The diesel compresses the air in the cylinder so fast and to such a high pressure that fuel immediately catches fire when sprayed into the cylinder. A gasoline engine doesn't reach this degree of heat and pressure, a spark plug starts the flame. Gasoline will ignite in a diesel setup long before its supposed to and that will destroy the engine. It's basically engine knocking on steroids
There have been some engineering studies to see if a gasoline engine could be made to run like a normal 4-stroke/ diesel combination, omitting the spark plug and using compression alone, with the normal intake and exhaust strokes, but this has issues like normal diesels. It can't be cold, or you need a block heater and glow plugs, which pretty much offset the benefits of the compression-ignition concept.