I’m gonna dream for a minute and see what anybody else cares to come up with if we were to be brainstorming a mechanical Dmax motor.
You’d have to...mount the pump, route high pressure lines in accordance to your camshaft firing order? Match a pump gear to your camshaft gear (not sure how you’d figure that). Fit whatever style injectors you wanted into a head, say custom screw in cups, with top feed mechanical injectors. Eliminate water pump, Fuel lines, belt driven lift pump? Belt driven oil pump? runner intakes, custom front engine cover list goes on and on.
Say you did all that and were able to turn the fuel way down on the pump so you could start out testing at a small horsepower number on stockish motors to figure out your setup before having a bagillion dollars in pistons, rods, girdles, heads, blocks.
Once you were ready for Big Power you’d have all of the years of mechanical tractors and cummins piston, injector, etc, etc, to cross reference to help make big powa?
Hypothetically speaking of course