Caterpillar D336

The Caterpillar D336 is a mechanical direct-injection diesel engine, not a complete machine: it was sold as a power unit for marine propulsion/auxiliary duty and industrial or generator-set drive, with no operator cab, undercarriage, or machine-style operating weight. Parts catalogs and engine-spec sheets most often document it as a V8, sharing gear-driven double-overhead-cam tooling with Caterpillar's 1676 highway-truck engine, though the exact valvetrain configuration carried under the D336 badge is not confirmed from an OEM spec plate in hand and should be read as reported rather than certain. Bare engine weight runs around 1300 kg (2866 lb), with rated output cited anywhere from roughly 225 to 350 hp (168-261 kW) depending on configuration and source. Caterpillar built the D336 through the 1960s-1970s as part of the D330/D333/D334/D336/D337 industrial-and-marine engine family covered under one Operation and Maintenance Manual (SEBU5304); the marine-rated variant carries the 60B serial prefix and was commonly paired to a marine reduction/reverse gear through an SAE No. 1-style flywheel housing, while other ratings within the family covered generator-set and stationary industrial drive duty.

Within the D330-D337 family, displacement and rated output generally step up moving from D330 toward D337, with the D336 sitting toward the upper end of that range; specific bore or output differences between the D336 and its D33x siblings are not independently confirmed here and should not be assumed identical across the family. Caterpillar's mechanical D-series industrial/marine line was phased out as the company's engine lineup transitioned to the 3000-series industrial and marine platforms through the late 1970s and 1980s, but no source ties a specific model to a direct, one-for-one D336 replacement, so any successor claim should be read as a family-level generational shift rather than a confirmed swap. The D336 matters in today's used and parts market because a working population of these fully mechanical, non-electronic engines is still running in older commercial vessels, standby gensets, and industrial drive applications where owners deliberately avoid ECM-equipped replacements; parts supply now depends on independent rebuilders and engine-parts specialists rather than a current Cat dealer parts counter, which keeps demand for good used cores, injection components, and heat-exchanger hardware active.

Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.