Preliminary review of the new diesel of Land Cruiser 300
Emissions grades: Euro 2-3-4-5, BS 6
The engine obtained a cast-iron cylinder block with a closed deck. The main bearing caps are integrated into a bearing beam carrier. At the rear side, the banks are connected by a bridging arch to increase rigidity.
For the first time for Toyota V6s a split balancer shaft installed, driven by crankshaft.
Pistons - of steel, with a combustion chamber, some unusual shape. Piston pin with DLC coating.
The crankshaft is made of carbon steel.
Cylinder head - with double-stage cooling jacket, with integrated exhaust manifold.
Valve mechanism - DOHC 24V: double camshafts in the heads and four valves per cylinder. There are valve adjusters and roller rockers in the valve mechanism.
Valvetrain is "two-step" - from the crankshaft by the primary roller chain to injection pump shaft, and then by secondary chains to all camshafts.
Auxiliary are driven by common belt with automatic tensioner.
The engine is equipped with a water oil cooler. The cylinder block contains oil nozzles for cooling and lubrication of pistons, equipped with check valves. In addition, the oil is supplied for turbochargers and vacuum pump.
The oil pump is installed on the crankshaft carrier and is driven by a separate chain.
Recommended oil types: Euro-II..IV - 5W-30/10W-30 API CF-4,CF / ACEA B3, B4, B5 / JASO DL-0 Euro-V..VI - 0W-20 ACEA C5, 0W-30..5W-30 ACEA C2
The cooling system is classic, the thermostat is rather "cold" (76°C) mechanical. Like V35, the fan has a belt drive, but instead of a simple viscous clutch, an electronically controlled hydraulic clutch is installed, which allows the fan to slow down at start-up, warm-up, idle and at low load.
In fact, the second cooling system with its own electric pump and two radiators is tied to an intercooler (also serves turbochargers, AdBlue supply module and exhaust fuel injector).
Intake and exhaust
A pair of turbochargers with variable geometry (VGT or VNT) at low speeds operate in single-turbo mode, at high speeds as twin-turbo.
To cool the charge air on the car, a large intercooler with autonomous liquid cooling is installed. An electric throttle valve is located in the intake.
Fuel system / Control
Common Rail type fuel system - the fuel is supplied by high pressure pump in a common rail and then is injected into the cylinders via the electronically controlled injectors. The injection pressure - up to 270 MPa. The system is branded i-ART (intelligent-Accuracy Refinement Technology)
Injection pump - HP5D type.
There are fuel pressure sensor and pressure discharge valve in the fuel rail. Electronically controlled valve opens and closes by a signal from the control unit, moreover, it can function of emergency pressure relief.
The injectors are of the electromagnetic type. They use individual fuel pressure and temperature sensors, which allow to accurately adjust the injection volume of each injector, as well as to determine their malfunction (clogging or leaks). The injectors are equipped with built-in memory and a self-learning function. The principle of operation is similar to the injectors of the GD series.
On models with two fuel tanks, an optional electric fuel pump is used.
Fuel filter - complex modular design with the ability to replace the filter element.
The exhaust has built-in low-pressure fuel injector supplied directly from the pump to raise the temperature of DPF for accumulated soot combustion.
Emission control system
As with the GD series, depending on the level of eco-standards, several combinations are possible: EGR, EGR+DOC, EGR+DOC+DPF, EGR+SCR-DPF+DPF
• EGR (Exhaust Gas Recirculation) is an advanced multi-mode structure with three valves and two coolers.
• DOC (oxidation catalyst) - primary stage of exhaust gas cleaning - oxidizes hydrocarbons and carbon monoxide to water and carbon dioxide.
• DPF (diesel particulate filter) - used to accumulation and combustion of soot particles.
• SCR (selective catalytic reduction) - used to reduce of NOx contents in the exhaust gas by injection of urea solution (AdBlue/DEF).