Toyota 1HD-FT

The Toyota 1HD-FT is a 4.20 l (4,164 cc, 254.1 cu-in) six cylinders, four-stroke cycle water-cooled turbocharged internal combustion diesel engine, manufactured by the Toyota Motor Corporation.

The Toyota 1HD-FT most known for its use in the Toyota Land Cruiser HDJ80. The 1HD-FT engine has a cast-iron block with 94.0 mm (3.7 in) cylinder bores and a 100.0 mm (3.94 in) piston stroke for a capacity of 4,164 cc (254.1 cu-in). Compression ratio rating is 18.6:1.

The motor has a cast iron cylinder head with a single overhead camshaft (SOHC) which is mounted on a three-layer steel laminate type head gasket.

The 1HD-FT engine is equipped with mechanical rotary fuel injection pump; central vertically mounted injectors and Toyota CT26 turbocharger with a boost pressure of 0.62 bar. The Toyota 1HD-FT produced 170 PS (125 kW; 167 HP) at 3,600 rpm of horsepower and 380 Nm (38.76 kg·m; 280.44 ft·lb) at 2,500 rpm of torque.

The breakdown of the engine code is as follows:

• 1 – 1nd generation engine
• HD – Engine family
• F – Economy narrow-angle
• T – Turbocharged

General information

Cylinder block

The cylinder block has a monoblock high-strength cast-iron structure with the seven-bearing-support system. The 1HD-FT engine is equipped with a forged crankshaft with seven forged journals and twelve balance weights.

The 1HD-FT motor has carbon-steel connecting rods and an aluminum alloy piston for high strength, lightweight and good heat conductivity; two compression and one oil control rings. The cylinder bore is 94 mm (3.7 in), piston stroke is 100 mm (3.94 in) and compression ratio rating is 18.6:1.

Main bearing cap tightening procedure and torque specs:

12 pointed head:

• Step 1: 103 Nm; 10.5 kg·m; 76 ft·lb
• Step 2: Turn all bolts 90°

6 pointed head:

• 18 Nm; 1.8 kg·m; 13 ft·lb

After securing bearing cap bolts, make sure crankshaft turns smoothly by hand.

Connecting rod bearing nut

• Step 1: 37 Nm; 3.75 kg·m; 27 ft·lb
• Step 2: Turn all bolts 90°

Crankshaft pulley bolt

• 430 Nm; 44.0 kg·m; 317 ft·lb

Flywheel (M/T) or Drive plate (A/T) fixing bolts

• 127 Nm; 13.0 kg·m; 94 ft·lb

Cylinder head

The 1HDFT has a one-piece high-strength cast iron cylinder head which is mounted on a three-layer steel laminate type head gasket. The engine has single (SOHC) high-quality carbon steel camshaft and aluminum rocker arms. Each rocker uses bridges to actuate a pair of valves. The engine does not have glow plugs but is equipped with an intake glow screen heater.

The camshaft is driven by a timing belt and gears. The timing gear train included a hydraulic auto tensioner. Furthermore, the timing gear train drove the oil pump, vacuum pump, steering gear pump, injection pump, and camshaft.

The engine has OHV design with four valves per cylinder: two intake and two exhaust valves, which are made of special heat-resistant steel. Intake valves are 33.0 mm (1.2992 in) in diameter, and the exhaust valves are 30.5 mm (1.2007 in). Intake duration is 224° and exhaust duration is 246°.

The 1HD-FT engine had an aluminum intake manifold and cast iron exhaust manifold that was mounted on a five-layer steel laminate type exhaust manifold gasket.

Head tightening procedure and torque specs:

• Step 1: 69 Nm; 7.0 kg·m; 51 ft·lb
• Step 2: Turn all bolts 90°
• Step 3: Turn all bolts 90°

Camshaft bearing cap

• 25 Nm; 2.5 kg·m; 18 ft·lb

Maintenance data

Vehicle applications

Author: Sergei Wers
About: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.