The Caterpillar D8H bulldozer uses a Caterpillar D342 turbocharged 6 cylinder diesel engine

Engine Specifications
Displacement: Approximately 20.4 liters (1,248 cubic inches)
Horsepower: Ranged from 225 to 270 net HP depending on the production year (early models started at 225–235 HP, while late-model D8H units were rated at 270 HP)
Aspiration: Turbocharged
Starting System: Typically featured a two-stroke gasoline "pony" starting engine, with electric starting available as an option on later versions
Historical Context
Introduction: Introduced in 1958 as a major redesign of the D8 line, marking the first time a turbocharger was factory-fitted to a D8 tractor.
Evolution: Production spanned through the 1960s and 1970s with continuous power bumps until it was replaced by the D8K in 1974, which utilized a higher-output version of the same D342 engine.