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Renault 5 Turbo intake and exhaust valves
175.00 €
In stock
Renault 5 Turbo intake and exhaust valves
Compatibility
- Renault 5 Turbo (type 8220)
- Renault 5 Turbo 2 (types 8220 and 8221)
Original Renault references: 7701461510 – 7701461511
| Type | Head diameter | Stem diameter | Length |
|---|---|---|---|
| Exhaust | 34.60 mm | 8.00 mm | 108.20 mm |
| Intake | 38.80 mm | 7.93 mm | 104.30 mm |
Why replace the original valves?
The original Renault 5 Turbo valves are bimetallic, with the stem and head friction-welded together.
Over time, this joint may develop a fatigue crack (see specifications): the valve head can break off and fall into the cylinder, causing major engine damage.
It is therefore essential to replace them with more reliable valves.
Quality & material
These valves are made from VA61 austenitic steel, known for its exceptional resistance to high temperatures and mechanical stress.
They are forged to ensure maximum durability, even under intensive use.
Price: Complete set of 8 valves, ready to fit.
Renault 5 Turbo valve technical specifications
Technical specifications & fitting advice – Renault 5 Turbo
Original construction
The Renault 5 Turbo was originally equipped with bimetallic valves: a Nickel-Chrome steel head and a Chrome-Silicon steel stem, joined together by friction welding.
Common causes of valve failure
- K-Jetronic mechanical injection: less precise than electronic injection, it can lead to higher exhaust temperatures if the settings are not perfectly adjusted.
- Excessive play in the valve guides: imperfect alignment between the valve and its seat generates alternating mechanical stresses, leading to fatigue failure of the valve.
- An extremely common issue on the Renault 5 Turbo, even on low-mileage engines.
Mespiecesauto improvement
Mespiecesauto has chosen to manufacture one-piece valves in high-temperature austenitic steel. This alloy is also used here for the intake valves, in order to ensure perfect thermal consistency and maximum durability.
Reassembly recommendations
When rebuilding a Renault 5 Turbo cylinder head, it is essential to carry out a complete metrological inspection:
- Checking the cylinder head flatness
- Checking the valve guide clearance
- Measuring the liner protrusion height
Renault 5 Turbo cylinder head data
- Type 8220: cylinder head height 80.8 mm – combustion chamber volume 50 cm³
- Type 8221: cylinder head height 81.0 mm – combustion chamber volume 50.9 cm³
Renault 5 Turbo reassembly advice
Renault 5 Turbo engine rebuild: reliability advice
The Renault 5 Turbo is generally a reliable car, but like many high-performance engines, it is highly sensitive to the quality of the engine reassembly. At Mespiecesauto, we remain at your disposal for any technical advice or questions during your restoration work.
Identify your engine: 840-730 or C7K700
Before any engine rebuild, it is important to precisely identify your engine block version:
- 840-730 engine: standard configuration for the Renault 5 Turbo.
- C7K700 engine: specific version with a 79.15 mm stroke and a 2.4 mm thick cylinder head gasket.
Checking liner protrusion
When refitting the cylinder head, careful measurement of the liner protrusion is essential:
- Recommended value: between 0.02 mm and 0.09 mm.
- Measurement must be carried out in a stepped pattern to ensure even distribution.
For more details, please refer to our Renault 5 Turbo metrology sheet: printable, downloadable and shareable.
Valve guides and wear
Excessive clearance in the valve guides leads to premature fatigue wear. For further information, please refer to the TRW technical publication on valve fatigue.
Combustion settings and valve seats
Accurate combustion control is crucial to ensure engine reliability. Contrary to some common beliefs, replacing the valve seats with “unleaded” versions is not essential on the Renault 5 Turbo. Fine combustion adjustment remains the priority to preserve engine longevity.
By following these recommendations, you will optimise the reliability and performance of your Renault 5 Turbo engine while respecting the original specifications.
