4 Valve or 5 Valve ??

[harrison]

Is the R 8 32 valve or 40?

[gazza1]

32(v8)40(v10)..4x Per Cylinder...

[Teutonic_Tamer]

32(v8)40(v10)..4x Per Cylinder...

Yup, correct. The reason they went from 5 valves per cylinder to 4 per cylinder is due to the siting of the FSI fuel injector - which injects straight into the combustion chamber, rather than the previous way of injecting into the inlet manifold.

[harrison]

Are ferrari F1 cars still 5 valve.Yamaha sports stopped 5valves a few years ago too. Less moving parts I guess makes faster.

[Dan1]

No, Yamaha stopped because the 5 valve motor just did not make any more power than a 4 valve.

It was a marketing gimmick.

[Teutonic_Tamer]

No, Yamaha stopped because the 5 valve motor just did not make any more power than a 4 valve.

It was a marketing gimmick.

5 valves per cylinder arn't really a marketing gimmick at all!

5 valves are all about inreasing or improving the volumetric efficiency of the cylinder. On a 5 valve head, you have 3 smaller inlet valves instead of 2 larger ones. If you then usually have a larger surface area from those 3 larger inlet valves, you then need less valve lift (compared to the 2) for the same volumetric efficiency. Less valve lift then = less loading on the camshaft, lighter valve springs, etc.