1HZ

From IH8MUD Wiki

The 1HZ 4.2 litre 6CYL was produced from 1990 to present, although it is no longer on sale in countries where it doesn't meet emissions standards. It has a rotary Denso fuel pump with built in lift pump and has indirect injection and SOHC. It uses glow plugs to warm the engine on cold starts. Models with PS have the pump built into the timing case as with the vacuum pump. It uses a timing belt to run the camshaft from the fuel pump which runs off the gears on the crank.

There is also a 5 cyl version 1PZ and turbo models 1HD-T, 1HD-FT and 1HD-FTE which have different heads, direct injection. They all share the same basic bottom end. There is some scant evidence of turbo 1HZ in the EPC but no firm proof has been made available in the form of an engine, nor is it mentioned in any FSM. Yanmar have 2 turbo direct injection models, marinised for boats.

The 1HZ was mainly sold in Australia and Africa where it used extensively in the mining, agricultural and construction industries, or in the family cruiser. The UN and the Australian govt were possibly the biggest single buyers of this engine.

It is used in mines in North America and other parts of the world but not availble to the general public.

It was available in all heavy duty 7* series, 80 series, 105 series, 100seriesIFS and Coaster buses.

Its very close in size and weight to other 6cyl diesel and petrol engines found in Landcruiser's

Its an extremely reliable quiet engine and is usually good for 500000 km with adequate maintenance and is simple to maintain. It also has little need for gaskets as most joints are suitable to be sealed with sealants. The gaskets it does have can be reused.

Specifications

Displacement: 254.1 Cu.In. (4,164cc)

Valvetrain: SOHC

Valves per cylinder: 2

Max Power: 129 Hp (96 kW) @ 3800 rpm

Max Torque: 210 ft-lbs (285 Nm) @ 2200 rpm

Bore x Stroke: 3.7" x 3.93" (94mm x 100mm)

Compression Ratio: 22.4:1

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