Your notes on Cosworth's CA 'compression' rings height (0.63mm) is not far off from my notes (0.5mm). But it was a total surprise from you quoting your notes as the rings material used by the 20000 RPM Cosworth, which must have had the highest ever piston speed used in F1 with its consequential fluttering limit being cast iron with CrN coated faces. Was more waiting for you to have found the time to contribute some by measuring YOUR TJ piston rings groves and tell the results.
isn't flutter is related to piston acceleration (not piston speed) ?saviour stivala wrote: ↑20 Oct 2019, 11:52....But it was a total surprise from you quoting your notes as the rings material used by the 20000 RPM Cosworth, which must have had the highest ever piston speed used in F1 with its consequential fluttering limit being cast iron with CrN coated faces.....
The ring 'flutter fatigue life' at such engine/piston speeds will certainly rule-out the use of cast-iron as a material of chose for piston rings.Tommy Cookers wrote: ↑20 Oct 2019, 16:12isn't flutter is related to piston acceleration (not piston speed) ?saviour stivala wrote: ↑20 Oct 2019, 11:52....But it was a total surprise from you quoting your notes as the rings material used by the 20000 RPM Cosworth, which must have had the highest ever piston speed used in F1 with its consequential fluttering limit being cast iron with CrN coated faces.....
and ok the ring flutter fatigue life would be improved (if the ring material was changed to steel or titanium)
but the flutter frequency (resonance) would be unchanged if the ring material was changed ?
In the case of titanium, flutter onset could be delayed due to lighter material.Tommy Cookers wrote: ↑20 Oct 2019, 16:12isn't flutter is related to piston acceleration (not piston speed) ?saviour stivala wrote: ↑20 Oct 2019, 11:52....But it was a total surprise from you quoting your notes as the rings material used by the 20000 RPM Cosworth, which must have had the highest ever piston speed used in F1 with its consequential fluttering limit being cast iron with CrN coated faces.....
and ok the ring flutter fatigue life would be improved (if the ring material was changed to steel or titanium)
but the flutter frequency (resonance) would be unchanged if the ring material was changed ?
Which is 32m/s in real money.Hoffman900 wrote: ↑24 Jun 2020, 06:58It would help to think in terms of piston velocity and not rpm. RPM is a bit meaningless without it, especially in terms of ring flutter. A NHRA Pro Stock engine (pre RPM rule) was seeing 11,000rpm with a 3.60" stroke. Piston velocity was rumored then to be over 6300fpm. Like NASCAR, they're in the .5mm range on the 1st and 2nd ring. Oil ring is around 2mm.