rotary engine

[deeligee]

hello all i just want to know why??? there are no rotarys in f1.

[Belatti]

Its a very intuitive ICE configuration, you know that thing as accelerating a mass, then decelerating it, accelerating it... again, you know how it goes, its a waste of power, but they are not in F1 because:

1) because they are forbbiden (ask Max )
2) because they have sealing problems: its expensive and difficult to get tight tolerances with "not round" geometry pistons (ask riff raff )

Still I think those engines are simpler, lighter and more efficient from a dynamic point of view and an effort must be done for the sealing problem to get solved, now more than ever with the new materiales availiable, the CAD-CAM and the needs for reducing fuel consumption.

[supertec]

I agree the sealing is definitely a concern. however I read an article that the engineers involved in Mazdas LeMans winning 787b have gone on the record as stating after disassembly they figured the engine could do another 24 hours.

[BJH_F1]

From what little I know about rotaries supposedly they don't take to well to heat cycling, that being one of their biggest faults (at least with past rotary designs and material choices). The particular issue being the tolerances between the apex seals and chamber with an increasing number of heat cycles (heating and cooling of the motor and vice versa). Once the rotary engine is warmed up to operating temperature it will run like a clock, typically with superior reliability to a piston engine, as demonstrated by the Mazda 787b in the 24 hours of Le man.

IMO, the rotary is a great engine for racing as it is relatively low on maintenance and cheap to repair. Besides being light and compact, the responsiveness and extremely linear power band make for a great racing engine. There really needs to be more research and development done on the rotary design, as technologies and materials may be able to capitalize on its simple and efficient design. Then again, there are so many new and promising ICE's being developed it may just be a waste of time to continue developing the rotary at this point. It's really too bad Max is stuck in his square box of thinking though ...F1 should really be a showcase of the latest and greatest technology in the automotive industry, with teams pushing to design new and much more efficient ICE's and hybrid designs. It's really quite hard to believe the naturally aspirated piston engine is still the engine of choice in Formula 1... thanks Max! You good for nothing....

[Ciro Pabón]

A reason is that if you accept them, you have to start to work some kind of equivalencies for the RPM: a rotary engine gives you three (or four, or whatever) "strokes" per revolution. I think you'll need some rule like "no more than x power strokes per revolution" and "not more than y volumetric displacement per revolution", which would complicate things a bit.

Mazda R26B: ain't a beauty?


As Belatti says, rotary engines would also require (or be burdened if they don't have) rules to equalize fuel consumption, as they are famous for bad fuel economy, which goes against the "green" thing. I'm not aware of recent advances in that field, probably they have had them at Mazda, I don't know if someone can help us here.

Rotary engines have a poor reputation for torque, altough some people argues the opposite. Again, I'm not aware of recent advances about that and I'm not sure about that issue: I haven's seen actual data.

As BJH_F1 clearly states, you cannot be totally sure about their reliability (the RX-7 guys will jump at that, I think). Anyway, once they're heated they work pretty well, but heat cycles impact them more than piston driven engines. I just repeated that argument to say that the rings on a regular piston are wonderful devices that sometimes makes you forget about "heat driven" tolerances in an engine.

Also, manufacturers have used more or less "exotic" materials to build them for regular cars, including (in times of yore) ceramic: that's another issue, as materials are restricted.

The sound is wonderful for many people, that's a plus.

They were accepted but not used, as far as I know, in Formula 3. The 2002 rules stated:

Cars with rotary piston engines covered by NSU-Wankel patents will be admitted on the basis of a piston displacement equivalence. This equivalence is 1.5 the volume determined by the difference between the maximum and minimum capacity of the working chamber.

They, again in my knowledge, contaminate quite a bit and are thirsty for oil.

Finally, no manufacturer in F1 produces them, and, under the current efforts to restrict costs, I wonder who will wish to spend the development money.

My conclusion is that, unless Mazda enters F1, you will never see them racing there.

[Carlos]

A rotary engine is basically a ported engine with a novel piston design, a rotational triangle piston, very much related to the 2 stroke, with all it's limitations and advantages, intake and exhaust controlled by uncontrolled tracts, fuel mixture flows in and out as if someone left the door open or remembered to close it and these design details create the engines shortcomings, poor mixture control, thermal hot spots, excessive fuel consumption and heightened emissions. BJH_F1, Ciro, Belatti said it better and first.

[ISLAMATRON]

yes, but all that is being fixed(improved atleast) with direct injection. A technology that F1 needs to adopt. DI is improving low end torque, emissions & fuel consumption all at the same time, As well as increasing power thruout the rev band. I have been working on & racing rotories for the last 10 years and I love them, thermal problems have arisen in the past but those have been overcome. thermal cycling is no longer a problem either with the better seals now imployed and proper heat up/cool down procedures.

I cant wait to get my hands on a turbo'd DI rotory of the future.

[Belatti]

I dont know why, when ISLAMATRON mentioned DI I began thinking about a piston that includes an injector in it. A weird idea, but after thinking a little deeper I realize the thing won´t work

[Carlos]

[quote="ISLAMATRON"]yes, but all that is being fixed(improved atleast) with direct injection. A technology that F1 needs to adopt. DI is improving low end torque, emissions & fuel consumption all at the same time, As well as increasing power thruout the rev band. I have been working on & racing rotories for the last 10 years and I love them, thermal problems have arisen in the past but those have been overcome. thermal cycling is no longer a problem either with the better seals now imployed and proper heat up/cool down procedures.

Yes DI - I quite agree. We did a thread on it about 18 months ago. where my posts, offered a lot of resources, you might enjoy looking in up, It's in here someplace, featured Orbital DI, case studies and synerject:
http://www.synerject.com/di.html

[ISLAMATRON]

thank you, quite interesting.