12 replies to this topic

[Henri Greuter]

Well, first of all, I am anything but a fan of the screaming V10s of the past. Glad they're gone.

 

Doesn't take away that some of the achievements with then and what they were capable off, I'm impressed and they are/were impressive.

 

Reputedly the highest RPM levels reached were around 20.000 RPM.

 

But the thing I wonder about is: even if was/is possible to get even more revs thanks to increased friction and resistance reducing matters and lubriation, is there a moment that the revs become too fast to enable a complete combustion with all fuel molecules being converted ino CO2 & H20.

 

I can imagine that if the stroke is reduced, and hence of it, the bore widened in order to reach the 3 liter capacity, the bore evenually becomes too  too wide to allow full combustion over the entire area of the piston, and thus inefficient use of fuel and therely limiting the maximum output possible for a 3 liter engine.

 

When Toyota came to F1, they considered a V12, even despite these were known for even more friction with and for the moving parts to overcome. Was the reduced bore due to using 2 more cylinders a factor in this?

 

 

Anything known and.or written about such matters?

 

 

Thnx, 

 

[Wuzak]

It depends on what power they are targeting, and what capacity they use.

 

If its 3L and upwards of 900hp, the rpm is going to be high, most likely over 15k.

 

500hp 3L engines, probably closer to what the V6s are doing now, and the old school Cossies were doing.

[Henri Greuter]

It depends on what power they are targeting, and what capacity they use.

 

If its 3L and upwards of 900hp, the rpm is going to be high, most likely over 15k.

 

500hp 3L engines, probably closer to what the V6s are doing now, and the old school Cossies were doing.

 

 

I was thinking about the continuation of the trend of the early 00's:  ever more revs in order to burn off more fuel in a given period of time in order to convert that onto more power.

And the hghest figures I have read were that one engine builder (BMW?) went over 20000.

 

But is more then that possible and still get more power? somehrere there must be a point that ever more res won't generate more power anymore due to incomplete combustion.

[lustigson]

I was thinking about the continuation of the trend of the early 00's:  ever more revs in order to burn off more fuel in a given period of time in order to convert that onto more power.

And the hghest figures I have read were that one engine builder (BMW?) went over 20000.

 

But is more then that possible and still get more power? somehrere there must be a point that ever more res won't generate more power anymore due to incomplete combustion.

 

I thought it was Cosworth who topped the 20,000 RPM mark, but 18,000+ would be quite feasible for a 3.0 V10 configuration, I'd say.

[gruntguru]

Probably the biggest technology advances produced by the current hybrid V6 formula have been in the area of combustion control.  Although a rich-of-stoichiometric, NA V10 is a very different beast, I have no doubt there are many learnings from the last 10 years that would permit burn rates sufficient for much higher than 20k rpm. I believe engine speeds would be limited by other factors.

[Magoo]

With no materials restrictions, 24,000 rpm. My shot in the dark. 

[gruntguru]

https://www.auto-mot...ement-2026/amp/

 

Makes this thread relevant.

[Bob Riebe]

If fuel, gasoline, was not spec. how high of a combustion ratio would the absolute be?

 

X thousand rpm, with z combustion ratio would change the HP, I believe.

 

Way back when Jaguar was in Trans-AM , they limited the HP by limiting the combustion ratio.

[scolbourne]

I have model engines that rev at over 30,000 rpm. The small Cox TD 010 can rev to 40,000. Small cylinders allow for fast revs, why V12 or V16 was popular in the 60's

 

Edited by scolbourne, 21 March 2025 - 13:15.

[7MGTEsup]

I have model engines that rev at over 30,000 rpm. The small Cox TD 010 can rev to 40,000. Small cylinders allow for fast revs, why V12 or V16 was popular in the 60's

 

 

The stroke is so short on those little engines I bet the mean piston speed is well below 25m/s even at 40000rpm. when you start scaling up it becomes much harder.

[Wuzak]

If fuel, gasoline, was not spec. how high of a combustion ratio would the absolute be?

 

X thousand rpm, with z combustion ratio would change the HP, I believe.

 

Way back when Jaguar was in Trans-AM , they limited the HP by limiting the combustion ratio.

 

Compression ratio?

[Wuzak]

It still comes down to the target power.

 

If they are 3.0L V10s, I would expect them to need fewer rpm for the same power as the V10s of the early 2000s.

 

As the manufacturers are involved in the discussions, it is likely that there will be a push for some type of ERS. In which case, the ICE output is likely to be lower than in the past.

[7MGTEsup]

It still comes down to the target power.

 

If they are 3.0L V10s, I would expect them to need fewer rpm for the same power as the V10s of the early 2000s.

 

As the manufacturers are involved in the discussions, it is likely that there will be a push for some type of ERS. In which case, the ICE output is likely to be lower than in the past.

 

I think even with a 15000rpm rev limit they would probably be in the 700hp range and less thirsty than they were in 2005. If you add in ERS they could be up at current power levels and be 50kg lighter than current cars.

Edited by 7MGTEsup, 02 April 2025 - 12:03.