Actual Rotary Displacement Request

[RICE RACING]

Originally Posted by Libor

I would be interested how we should approach "displacement" of unnusual engines. Like Ilmor "5-stroke" where three cilinders are creating working unit - two outer are regular and middle one is bigger and extracts addition power from still expanding exhaust gasses.

By definition of displacement from above, such engine would be described as sum of displacements of individual cilinders. But only two cilinders have Intake and are doing pumping work of working fluid.

Displacement on its own means nothing without considering working cycle.

[RICE RACING]

Anyone of you nobodies could just as easily spend some of your time instead of trying to pass analysis on me spend some time on trying to figure out how a rotary works!

Now there is a novel concept!@

Equivalence does not equal displacement, and the Wankel is the ONLY engine where its cycle is not acknowledged nor are ALL of its working elements............... this is not that hard really to comprehend.

for those of you that are stuck or are uneducated in the formal prerequisites to pass qualified commentary then you can stick to your partial false analysis and use the well worn out equivalence factors I mentioned in my second post.

Is any of them Wankel? Is any of them complete? NO! Practice and learn and you may get it one day

[RICE RACING]

The problem with most of you is you are forgetting the Wankel shares a common combustion chamber, intake and exhaust port per rotor for 3 rotor faces.

What is not in dispute is that it takes 1080deg for the Wankel cycle to complete, it is in every proper text you will find on the topic. It does not take rocket science to then see it will equal 3 times the rated partial operating cycle some like to quote as the "capacity".

Sure its 1.3lt in one rev
And its 2.6lt in two revs
But I say again and again it takes three revs to complete the Wankel cycle, nothing more and nothing less. And it will displace 3.9lt for a 13B in that time.

[RICE RACING]

FOr some who love comparisons or measuring to others (why would you I dont know but.........)

The 13B is like the following

Power density like a 1.3lt 2 stroke!
Fuel consumption of like a bad 2.6lt 4 stroke!
Racing durability similar to a equal powered 3.9lt!

Some old boys will get what I am saying with the above.
The Wankel has allot of good attributes with its very large areas and slow speeds and this shows up in its durability as a racing engine (on equivalence basis for time related "displacement" @ equal BHP levels) compared to reciprocating alternatives. When you understand how the engine works and why this is you quickly see its not magic but its an attribute of the Wankel Cycle, its slow speed, and big area to time relationships. Sure its inefficient on ANY equivalence measure (power density, peak speed, etc) but BANG for BUCK and DURABILITY wise its very very very hard to beat.

I don't know if there are many or any on this forum who get WTF I just said but hopefully it will ring true to someone who has more than a shitty web page with fictional customer base and delusions of self praised status.

Wankels are a cool motor its only the people into them in the majority that are weird!

[Barry Bordes]

Originally Posted by RICE RACING

FOr some who love comparisons or measuring to others (why would you I dont know but.........)

The 13B is like the following

Power density like a 1.3lt 2 stroke!
Fuel consumption of like a bad 2.6lt 4 stroke!
Racing durability similar to a equal powered 3.9lt!

Some old boys will get what I am saying with the above.
The Wankel has allot of good attributes with its very large areas and slow speeds and this shows up in its durability as a racing engine (on equivalence basis for time related "displacement" @ equal BHP levels) compared to reciprocating alternatives. When you understand how the engine works and why this is you quickly see its not magic but its an attribute of the Wankel Cycle, its slow speed, and big area to time relationships. Sure its inefficient on ANY equivalence measure (power density, peak speed, etc) but BANG for BUCK and DURABILITY wise its very very very hard to beat.

Wankels are a cool motor its only the people into them in the majority that are weird!

It is interesting that you should describe the Rotary that way.

While watching the 24hrs of Le Mans I had a similar thought. In the parallel universe where the wankel displacement is measured after one full rotation the rotor, it could be argued that Rotor RPM would also be used and not the PTO shaft (eccentric shaft) RPM.

This would necessarily change our perspective of the Mazda win in 1991. Of course Mazda should have beaten Jaguar, Mercedes, and Porsche.

Its engine was much larger at 7848 cc, and it loafed along at 2300 RPM with a red line of 3000RPM.

It won with its superior fuel economy of this slow turning large displacement rotary.

Barry