Komatsu 6D102-1-Z(S/N 30707205-UP)

The 6D102-1-Z is a mid-range industrial diesel in Komatsu's 6D102 family: water-cooled, inline six-cylinder, roughly 5.9-liter displacement with a 102 mm bore. The S/N 30707205-UP break covers the mechanically governed, non-electronic build of that engine as factory power in Komatsu's D41A-6 crawler dozer, early 830-series motor graders, the WA180-3L and WA250-3L wheel loaders, and the 150A/150FA rough-terrain crane chassis. Rated output runs from roughly 82 hp on the dozer up toward 150 hp on the grader depending on host machine and governed speed - varies by configuration/series. Host machine operating weights span from about 9.3 metric tons (20,500 lb) on the smaller wheel loader to around 12.6 metric tons (27,800 lb) on the grader. These platforms date from the late 1980s through the late 1990s, spanning Komatsu's Dash-6 dozer generation and the Galion/Komatsu-Dresser crane and grader lines the company folded in through its joint venture with Dresser Industries. In shared chassis like the 150A/150FA crane, Komatsu offered this mechanical engine alongside a turbocharged, electronically governed S6D102E-1 option, so buyers could choose mechanical simplicity over electronic injection control.

Komatsu moved its 830-series grader to the larger 6D114E-1 engine in the 830B and 830C updates, and its dozer and wheel loader lines shifted toward turbocharged, electronically governed 6D102E and later SAA6D102E variants as emissions rules tightened through the 1990s and 2000s. That leaves the 6D102-1-Z as a late mechanical-generation engine: no electronic injection control, no aftertreatment, and a block and injection architecture simple enough to rebuild in the field. Because it was fitted across dozers, graders, wheel loaders, and cranes rather than a single model line, used cylinder heads, injection components, and long blocks stay in wider circulation than a single-application engine would support. For shops keeping D41A-6 dozers, early 830 graders, WA180-3L/WA250-3L loaders, or 150A/150FA cranes running past their original service life, that cross-application parts base is the main reason this engine still has a working presence in the used and rebuild market.

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