Cummins

Holset compressors for Cummins engines offer high-output performance for demanding applications. Includes QE296, QE338, SS296, SS338, and ST676 variants.

Suffixes like B and C identify the engine platform—Cummins B series or C series—and when followed by E, they indicate an E-Type unloader configuration for that engine series. Meanwhile, prefixes such as SS (Super Single), ST (Super Twin), and QT (Quiet Economy) define the compressor family before the model number.

HD Series	Description	Engine	Sequence Code
HD450	Small-bore crankcase with special piston	B-Series	High Mount Manifold 1-4-3-U /Low Mount Manifold 3-4-1-L
HD650	Small-bore crankcase	C-Series	High Mount Manifold 4-3-4-3/4-3-1-3
HD850	Large-bore crankcase	N14/L10	High Mount Manifold 4-1-3-3