Discovery Energy 15LD350

The 15LD line represents Lombardini's classic air-cooled small-diesel range, distinct from the later water-cooled LDW types; the sources reviewed give no exact introduction year.

Thanks to its light weight and simple air-cooled design, the 15LD 350 is widely used in farm equipment, single-axle two-wheel tractors, vibrating plates, mini excavators and mini dumpers, as well as small generators and welding sets; manufacturers cited among its users include JCB, SDMO, Bomag and Weber.

As a nonroad engine, the 15LD 350 falls under EU Stage or US Tier emission limits for mobile machinery rather than the Euro or EPA road rules for vehicles used in public traffic, since it powers only stationary or hand-guided work equipment. Unlike a vehicle engine with varying load and speed, it typically runs at a fixed governed speed so that connected equipment such as generators or pumps operates at a constant frequency or output. Air cooling through cylinder fins and a fan makes the engine independent of a cooling circuit with radiator, water pump and thermostat, as needed on liquid-cooled stationary engines, but increases noise and heat radiation.

Because of the air cooling, used units deserve a close check of clear cooling fins and an intact fan drive; no further type-specific weak points are documented in the sources reviewed.