this may kinda sound like a stupid question but whats the differnce in direct and indirect injected engines?

No questions are stupid.



Indirect means the injectors are not spraying fuel directly into the
combustion chamber. The 6.2/6.5 heads have a smaller "mini" combustion
chamber cast along side of the main head chamber and connected to it.
It provides a smaller area for fuel and the glow plug to ignite the
fuel.



Direct injection has a conventional style head with the injector in the center similar to spark engines.



The older diesel engines had less injection pressures which made them
harder to start and smoky. That's why they went with the prechamber
design.



With todays higher injection pressures, more advanced aux heating
devices and computer controlled injectio events, direct is the norm.


Edited by: hoot

It is interesting that GM put a channel in the piston top to route the prechamber combustion toward the piston center.