Toyota HD engine
1989 Toyota 1HD-T engine
Overview
Manufacturer	Toyota Motor Company
Layout
Configuration	Straight-6
Displacement	4.2 L (4,164 cc)
Cylinder bore	94 mm (3.70 in)
Piston stroke	100 mm (3.94 in)
Valvetrain	SOHC 12 & 24 valves
Compression ratio	18.6:1, 18.8:1
RPM range
Max. engine speed	4200
Combustion
Turbocharger	Yes, with intercooler (some versions)
Fuel system	Direct injection
Fuel type	Diesel
Cooling system	Water-cooled
Output
Power output	164–420 hp (122–313 kW; 166–426 PS)
Torque output	361–430 N⋅m (266–317 lb⋅ft)

The Toyota HD is a series of Diesel engines produced by Toyota.

1HD-T

The 1HD-T is a 12 valve 4.2 L (4,164 cc) straight-6 SOHC turbocharged direct injection diesel engine .^[1] Bore and stroke is 94 mm × 100 mm (3.70 in × 3.94 in), with a compression ratio of 18.6:1. Output is 164 hp (122 kW; 166 PS) at 3,600 rpm with 361 N⋅m (266 lb⋅ft) of torque at 1,400 rpm.^{[clarification needed]}

• Coaster, HDB20, January 1990 – January 1993
• Coaster, HDB30, January 1990 – January 1993
• Coaster, HDB50, January 1993 – January 1995
• Land Cruiser, HDJ80, January 1990 – January 1995

1HD-FT

The 1HD-FT is a 4.2 L (4,164 cc) straight-6 24 valve SOHC turbocharged direct injection diesel engine . Bore and stroke is 94 mm × 100 mm (3.70 in × 3.94 in), with a compression ratio of 18.6:1. Known as the "multivalve" it has 4 valves per cylinder (2 inlet, 2 exhaust), central vertically mounted injector, and no glow plugs but rather an intake glow screen heater (like the later electronic 1HD-FTE below). The 4 valves per cylinder are actuated by the SOHC, by using bridges so each rocker actuates a pair of valves. Output is 168 hp (125 kW; 170 PS) ECE at 3,600 rpm with 380 N⋅m (280 lb⋅ft) of torque ECE at 2,500 rpm. However, marinized version of 1HD (sold as Yamaha ME and Yanmar 6LP) have an output of 315 hp (235 kW; 319 PS) on Yanmar 6LP and 315 hp (235 kW; 319 PS), 370 hp (276 kW; 375 PS) or 420 hp (313 kW; 426 PS) on Yamaha ME.^{[2][3][4][5][clarification needed]}

• Land Cruiser, HDJ80, 1995
• Coaster, HDB50, July 1995 – July 1999
• Land Cruiser, HDJ80, July 1995 – July 1999
• Yanmar 6LP and Yamaha ME diesel engine (marinized version of 1HD-FT).

1HD-FTE

The 1HD-FTE is a 4.2 L (4,164 cc) straight-6 24 valve turbocharged diesel engine. Bore and stroke is 94 mm × 100 mm (3.70 in × 3.94 in), with a compression ratio of 18.8:1. Output is 167 hp (125 kW; 169 PS) at 3,400 rpm with 380 N⋅m (280 lb⋅ft) of torque at 1,400 rpm. The fuel system is direct injection, and adopts the electronic fuel injection (EFI) system. Redline of this engine is at 4200 rpm.

The 4 valves per cylinder are actuated by the SOHC, by using bridges so each rocker actuates a pair of valves.

The version with intercooler as fitted to HDJ100 station wagons has 202 hp (151 kW; 205 PS) at 3400 rpm with 430 N⋅m (317 lb⋅ft) of torque at 1200-3200 rpm with a redline reaching 4000 rpm. A lower output 122 kW (164 hp; 166 PS) non-intercooled version powers HDJ78 Troop Carrier and HDJ79 Utility versions.

Also some of the HDB50 and HDB51 Coasters are fitted with this 1HD-FTE engine.