At such small included angles, a change in included angle makes a small difference in the maximum valve size. There are additional benefits to "splaying" the valves both longitudinally and lattitudinally (porcupine arrangement):saviour stivala wrote: ↑Fri Aug 21, 2020 6:20 pmThe ''Goetze'' made and supplied piston rings (uncoated 2 rings per piston) Illmor used 30 years ago on their in-house machined but contracted-out forged RR58 (2618A) aluminium alloy pistons were off-the shelve items. there was no technical specialities about piston rings used in F1 at that time apart from careful tolerance selection.
Yes. the 22 degrees ''included'' valve angle I quoted was when viewed from front. This valve included angle used in the 3.0-litre era (late nineties) were all around 25 degrees or less, and some were even less 20 degrees.
Compound valve angles to maximise valve sizes. 2 valves on each side (2 intake) or 2 exhaust) splayed rather than parallel to each other. the compound angle maximized valve size to an extent that could see intake valve area reach as much as 39%of bore size.
Will have to check my notes re the ''splayed'' (front to back) compound valve angle and comes back to you.
''cams ran directly in the head'' means cams runs/rotate directly in the head material and no replaceable bearing shell/bearing bushes are used.
- directing the valve axis towards the bore axis improves flow. Flow at the short radius dues not have to turn as much to follow the bore.
- Inclining the valves more would further improve flow but combustion chamber shape suffers and compression ratio is physically limited.
- Combustion chamber shape is improved and surface area reduced.