The EMD 567 is a line of large medium-speed diesel engines built by General Motors' Electro-Motive Division.

The 567 proved to be exceptionally successful in passenger, switching, freight, marine and stationary services, and, counting its two successors, the 645 and 710, which are not materially different from the 567 (all have the same external dimensions, differing mainly in per cylinder displacement), collectively have given nearly 80 years of exceptionally reliable service to those applications.

The 201A was 60° between cylinder banks; 45° later proved to be significant when EMD subsequently adapted the road switcher concept for most of its locomotives, and which required the narrower (albeit taller) engine which 45° provides.

The engine is a uniflow design with four poppet-type exhaust valves in the cylinder head.

Each bank of cylinders has an overhead camshaft which operates the exhaust valves and the unit injectors.

[8] All engines have mechanically-controlled unit injectors (patented in 1934 by General Motors, EMD's former owner).

The turbocharger (a combination turbo-compressor system) follows EMD's innovative design that uses a gear train and over-running clutch to drive the compressor rotor during low engine speed, when exhaust gas temperature (and, correspondingly, heat energy) alone is insufficient to drive the turbine.

At higher engine speeds, increased exhaust gas temperature is sufficient to drive the turbine and the clutch disengages, turning the turbo-compressor system into a true turbocharger.

The turbo-compressor can revert to compressor mode momentarily during demands for large increases in engine output power.

While more expensive to maintain than Roots blowers, the turbocharger significantly reduces fuel consumption and emissions, while improving high-altitude performance.

[9] The 567 gave way to the 567A in 1941, which incorporated further top deck improvements and camshaft gear train changes.