The Renault Z7X 3.0-liter 12-valve engine is part of the V6 PRV lineup. This family of V-shaped 6-cylinder engines was introduced in 1974 and consisted of a series of units with a volume of 2.5 to 3 liters, including turbo ones. They can be found under the hood of Renault 25, Safrane, Laguna and Espace models.
The development of a new family of multi-cylinder engines began in 1966 with the joint efforts of Renault and Peugeot-Citroen engineers, later Volvo joined them. After 3 years, a joint venture was opened in the city of Duvrin, and in 1974 the first V6 power unit rolled off the assembly line.
Initially, the designers designed the V8 engine, but the fuel crisis made its own adjustments and had to get rid of two cylinders. That is why it has a camber angle of 90° instead of the usual 60° for V6 units. In total, by 1998, about a million copies had been collected.
This engine was widely used in supercars and sports cars: Alpine GT, Helem V6, UMM Alter II, Venturi 260 LM, and of course the DeLorean DMC-12.
|Start of production||1974|
|Power output, hp||165 – 170 (atmospheric version)
268 (Bi-Turbo version)
|Torque output, Nm||230 – 235 (atmospheric version)
365 (Bi-Turbo version)
|Valves per cylinder||2|
|Cylinder bore, mm||93|
|Piston stroke, mm||72.7|
|Compression ratio||9.6 (atmospheric version)
7.6 (Bi-Turbo version)
Disadvantages of the Z7X engine
- The most frequent calls to the service are related to the fact that the engine does not start, stalls or twitches due to the fault of some sensor. Fuses and relays often blow out, wiring rots, contacts are oxidized. Especially if the car is idle for a long time.
- Unstable operation of the motor is usually associated with air leakage through cracks in the vacuum tubes going to the MAP (Manifold Absolute Pressuresensor) sensor. Less commonly, a dirty air damper or a broken fuel pump is to blame.
- An unreliable ignition system regularly leads to tripping of the power unit. The reason may be in the coil, distributor, high-voltage wires or candles.