Introduction
Toyota’s 5VZ-FE was a 3.4-litre V6 petrol engine that, for Australia, was offered in the 90-Series LandCruiser Prado andMk.6 Hilux. Key attributes of the 5VZ-FE engine included its:
- Deep-skirt cast iron block;
- 60 degree ‘V’ angle;
- Aluminium alloy cylinder head;
- Double overhead camshafts (belt and gear driven); and,
- Four valves per cylinder.
| Engine | Trans. | Years | Peak power | Peak torque | |
|---|---|---|---|---|---|
| Toyota90-Series LandCruiser Prado | 3.4-litre petrol V6 | 5sp man., 4sp auto |
1996-02 | 132kW at 4800rpm | 303Nm at 3600rpm |
| ToyotaMk.6 Hilux | 3.4-litre petrol V6 | 5sp man., 4sp auto |
2002-05 | 124kW at 4600rpm | 291Nm at 3600rpm |
5VZ-FE block
The 5VZ-FE had a deep-skirt, cast iron cylinder block with vermicular cast-iron main bearing caps. For balance and even 120 degree firing intervals, the cylinder banks were positioned for a 60 degree ‘V’ angle. The 5VZ-FE engine had 93.5 mm bores and an 82.0 mm stroke for a capacity of 3378 cc.
Crankshaft, connecting rods and pistons
The 5VZ-FE engine had a cast iron crankshaft. Initially, the crankshaft had five balance weights, though the crankshaft for the 90-Series LandCruiser Prado had nine counter-weights (and a dual-mode damper) to minimise vibrations.
The 5VZ-FE engine had forged, sintered connecting rods and aluminium pistons with full floating type piston pins. For optimum oil retention, the pistons had striated skirts.
Cylinder head and camshafts
The 5VZ-FE engine had an aluminium alloy cylinder head and camshaft cover. For the double overhead camshafts (DOHC), the inlet camshafts were driven by a belt and the exhaust camshafts were driven by ‘scissor’ gears off the inlet camshafts (i.e. belt and gear drive) – this arrangement enabled the camshafts to be positioned close to one another for a narrow 22.5 degree included valve angle.
Valves and timing
The 5VZ-FE engine had four valves per cylinder – two intake and two exhaust – that were actuated directly to minimise valvetrain inertia. As per the table below, the 5VZ-FE engine had valve overlap of 8 degrees, intake duration of 226 degrees and exhaust duration of 230 degrees.
| 5VZ-FE Valve Timing | ||
|---|---|---|
| Intake | Open | 4° BTDC |
| Close | 42° ABDC | |
| Exhaust | Open | 46° BBDC |
| Close | 4° ATDC | |
Intake and throttle
The 5VZ-FE engine had long intake runners to increase torque and a resonator to reduce induction noise.
The 5VZ-FE engine had a conventional throttle body whereby the throttle valve opening was determined by the amount of accelerator pedal effort. Furthermore, the 5VZ-FE engine had a linear type throttle position sensor and a rotary solenoid type Idle Air Control (IAC) valve was integrated with the throttle body.
Both the intake manifold gasket and intake air chamber gasket had a rubber coating.
Injection and ignition
The 5VZ-FE engine had an L-type sequential, multiport fuel injection system. The ‘air-assisted fuel injection system’ for the 5VZ-FE engine regulated air intake to the upper stream of the throttle valve using the Idle Air Control valve and directed it to the nozzle of the fuel injector inside the intake manifold (negative pressure side) – this improved fuel atomisation, fuel economy and idle stability. For the 5VZ-FE engine, intake air mass was measured directly with a hot wire type mass air flow meter.
It is understood that the 5VZ-FE engine initially had two-hole injectors, though four-hole injectors were subsequently introduced.
The ‘Direct Ignition System’ (DIS) for the 5VZ-FE consisted of three sets of ignition coils – that were integrated with plug caps – and with high-tension cords that attached directly onto the ignition coil. As such, the 5VZ-FE had a two-cylinder simultaneous ignition system which ignited two cylinders simultaneously with one ignition coil. The ignition coils had a magnet (rather than an iron core) to increase magnetic flux and reduce the number of coiled wires required within the coil. By eliminating the distributor, DIS improved ignition timing, reduced high-voltage loss and improved the reliability of the ignition system.
The 5VZ-FE engine had Toyota’s ‘Electronic Spark Advance’ (ESA) which used the ECM to determine ignition timing based on signals from sensors and adjust timing in response to engine knocking.
The 5VZ-FE engine had pentroof-type combustion chambers and a compression ratio of 9.6:1.
Exhaust and emissions
The 5VZ-FE engine had a stainless steel exhaust pipe, while a clamp type joint was used to join the centre exhaust pipe and tail pipe.
For the 90-Series LandCruiser Prado, the main muffler had a variable exhaust valve that opened steplessly according to back pressure. The exhaust valve was closed at low engine speeds to reduce engine noise and opened at higher engine speeds to reduce back pressure and increase power.
