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You got your second message in before I could reply about your earlier suggestion of sleeve valves!!!!

The 5 stroke engine was discussed three years ago in a thread about regenerative future engine technology.

I'm not convinced that a reciprocating second stage is the best type of machine. I can imagine that an inverted turbo compressor working as an expander would make a better second stage machine. The five stroke is mechanically simple but not exactly the pinnacle of efficiency.



Stationary rotary compressor.



Simplified automotive Sprintex compressor.

machin wrote:You got your second message in before I could reply about your earlier suggestion of sleeve valves!!!!

The only real problem with sleeve valves is the method of driving the sleeve.
Using a small geared crank restricts rpm and the cost then cuts across the benefits over poppet valves.
Do away with mechanical drive on the sleeve and the sky is the limit.
With modern manufacturing, I no longer see to much of a cost problem.

WhiteBlue wrote:The 5 stroke engine was discussed more than a year ago in a thread about future engine technology. I'm not convinced that a reciprocating second stage is the best type of machine. I can imagine that an inverted turbo compressor working as an expander would make a better second stage machine. The five stroke is mechanically simple but not exactly the pinnacle of efficiency.

Good point WhiteBlue. However a turbo on a five stroke is much better.
Perhaps somebody can do the math.
The other way is a wankel rotary with a turbo/generator coupled to a hybrid or kers system.

autogyro wrote:

WhiteBlue wrote:The 5 stroke engine was discussed three years ago in a thread about regenerative future engine technology.

I'm not convinced that a reciprocating second stage is the best type of machine. I can imagine that an inverted turbo compressor working as an expander would make a better second stage machine. The five stroke is mechanically simple but not exactly the pinnacle of efficiency.



Stationary rotary compressor.



Simplified automotive Sprintex compressor.

Good point WhiteBlue. However a turbo on a five stroke is much better.
Perhaps somebody can do the math.
The other way is a wankel rotary with a turbo/generator coupled to a hybrid or kers system.

The thermodynamics of two stage heat/power cycles are not trivial. Just the selection of boundary conditions require massive experience with some experimental prototypes. I would doubt that anybody not involved with engine development work and educated in advanced thermodynamics can do the job.

Quick question, by sleeve valves, are you guys reffereing to the same type of "valves" my 2 stroke rc engines use ( aka "ports" )

hecti wrote:Quick question, by sleeve valves, are you guys reffereing to the same type of "valves" my 2 stroke rc engines use ( aka "ports" )

No

http://en.wikipedia.org/wiki/Napier_Sabre

http://www.hawkertempest.se/NapierSabre1.htm

http://en.wikipedia.org/wiki/Sleeve_valve

WhiteBlue wrote:

Pingguest wrote:The thing I like about the GRE is the possibility for manufactures to use one basic engine block for a number of racing series. But I don't like the idea of a mandatory configuration, like the proposed 1.6-litre L4T. Wouldn't be better to allow any engine configurations and limit the fuel-flow? The fuel-flow limits could be enforced by using fuel-flow meters....

There is one issue with fuel flow control and modern efficient petrol engines. The direct stratified injection will enable massive savings when on partial loads. This means for most F1 courses when the engine isn't on full song consumption will be lower. If you introduce fuel flow limits you would never get top power because you cut that segment off.

Would that be a bad thing? Lowering fuel economy is just what Formula 1 should do. Introducing fuel-flow limits will create an incentive to extract maximum power from the limited fuel flow. Besides, a fuel-flow limit is very easy to enforce in qualifying too whereas a fuel consumption limit is unpractical in qualifying.

It would also force the teams to redirect the aero development away from increasing DF and towards more efficient ways to cut through the air to save fuel.
The blown rear wings that give a smoother car on the straits, be it only 3 mph is proof of this changing priority.
Take the power down and rely on energy recovery, then you will see aero change for the better and guess what; more overtaking.
Wet weather can be used as an almost exact example of the effect, where the drivers cannot use the power available, the racing gets closer.

autogyro wrote:It would also force the teams to redirect the aero development away from increasing DF and towards more efficient ways to cut through the air to save fuel.
The blown rear wings that give a smoother car on the straits, be it only 3 mph is proof of this changing priority.
Take the power down and rely on energy recovery, then you will see aero change for the better and guess what; more overtaking.
Wet weather can be used as an almost exact example of the effect, where the drivers cannot use the power available, the racing gets closer.

In the ideal situation the introduction of fuel-flow limits should go along with together wit a ban on diffusers. A reduction of downforce in general and a reduction of downforce coming from the underbody in particular is good for the racing, as said by Paddy Lowe too.

Just to show that I do not want to see a complete break with ic engine development, I have posted another link to sleeve valve technology, which remains the 'peak' of ic development cancelled when overtaken by turbo jets.
I would like to see the valving of F1 opened up and much more open engine regulations, so that at last ic engines can be brought to the ultimate efficiency.
It simply needs this to be coupled to sensible fuel restriction.

http://en.wikipedia.org/wiki/Rolls-Royce_Crecy

The Crecy development included many things that are still way ahead of even current F1 engine technology.

autogyro wrote:It simply needs this to be coupled to sensible fuel restriction.

The question that needs to be answered then is, what fuel-flow limit and/or fuel consumption limit is sensible. To me, I can't see why Formula 1 shouldn't have internal combustion engines that produces more than 650bhp. It would promote the use of powerful wasted energy recovery systems.

Do you remember not so long ago FIA suddenly spoke sense in telling that the next engine regulations should be based on limiting the amount of energy and not displacement (and other specs)? As far as I can recall that was during the last months of Mosley's reign. Where has that gleam of reason gone to?

EDIT: found the news story http://www.jamesallenonf1.com/2009/10/f ... ng-future/

Pandamasque wrote:Do you remember not so long ago FIA suddenly spoke sense in telling that the next engine regulations should be based on limiting the amount of energy and not displacement (and other specs)? As far as I can recall that was during the last months of Mosley's reign. Where has that gleam of reason gone to?

EDIT: found the news story http://www.jamesallenonf1.com/2009/10/f ... ng-future/

You must ask Fota Ferrari and Briatore to get the answer to that question.
Of course Max is still the only person with the experience and strength of character to ensure such sensible regulations actualy happen and get enforced.
Interesting to see that Jean Todt has yet to decide on the new F1 top official.
A thankless task but there realy is only one person for the job.

Max had his chance but kept implementing the exact opposite policy for how many years?