Ok so on the SMARTY you can adjust th timing. I am a little stumped. How exactly does it change timing? I mean with a gasser it alters at what degree the crank is at when the spark plugs go off. With a diesel not using spark, but the compression of the fuel to ignite the fuel.... How exactly do you change the timing without different grinds on your crank?

 

the timing changes when the injector opens i believe more injection timing gives you more fuel. when you have to much timing it will hit a certain spot of the piston causing a hotspot and a melt down. timing also increases drive pressure

 

All of this is about the common rail system where fuel pressure is waiting at the injector.

The computer is getting information from the crank position sensor and is "deciding" when to start the injection based on the crank's position. It starts the injection by energizing the injectors at a certain crank position. This is equal to spark in a gasser and is when the fire starts. More throttle means a longer time that the injectors are energized. Smarty changes the computer programming to start the injection earlier, or more advanced.

It seems that retarded ignition is better for emissions, but worse for economy and power, so they were set up retarded by Cummins. Meanwhile, cylinder pressure is adequate to start the fire over a wide degree of rotation.

Bigger injectors act like advanced timing, to a certain degree, because they get the injection overwith earlier under light load. Not starting earlier, but finishing earlier.

 

Actually diesel engines compress only air at high compression ratio and injects the fuel into the super heated air in the cylinder causing an explosion (AKA auto ignition).

Smarty alters the ECM's programing as when to open the injector solenoid. Retarded timing = lowers NOX, power & MPG; advanced timing = increase NOX, power & MPG along with a little more timing rattle.

 

got it. thanks guys. I was thinking that thye fuel and air were being compressed together. So I ws stumped as to how you could alter the timing.