Before you order an engine for a Komatsu PC40-7, check the cylinder count - this class spans three-cylinder and four-cylinder Komatsu engines. Where it is the three-cylinder 3D84E, the 3D88 is the established replacement, and we stock it new surplus and rebuilt.
The Komatsu PC40-7 is a 4-ton class mini excavator from Komatsu's -7 compact series, still common in US contractor fleets. CYLINDER COUNT WARNING: PC40 and PC45-class machines were also built with the four-cylinder 4D88E. Confirm the cylinder count on the data plate - this is the single most common mix-up in this size class.
ENGINE SPECIFICATION. Three cylinder, four cycle, water cooled, vertical in-line. Direct injection, naturally aspirated. Bore and stroke 88 x 90 mm. Displacement 1.642 L (100.2 cu in). Around 36 hp at full rated speed, less in machines governed lower. Dry weight approximately 341 lb (154 kg). Engine as fitted to this machine: Komatsu 3D84-2 / 3D84E. Production years: 1995-2003. Original rated output: approximately approx. 33 hp.
WHY THE 3D88 REPLACES THE 3D84E.
Komatsu's 3D-series three-cylinder diesels are one family on one architecture - the same 90 mm stroke, the same block design, the same mounting and accessory layout. Only the bore changes:
3D82AE - 82 mm bore, 1.331 L, around 29 hp (Yanmar 3TNV82A)
3D84 / 3D84E - 84 mm bore, 1.496 L, around 33 hp (Yanmar 3TNE84 / 3TNV84)
3D88 / 3D88E - 88 mm bore, 1.642 L, around 36 hp (Yanmar 3TNE88 / 3TNV88)
Because the 84 mm and 88 mm engin