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 |
