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.

[mzivtins]

Some facts to help see why these engines may have not been used in F1:

They are designed to burn oil.
Everyone knows of rotary engines. Most know of the reliability... or lack of, to be precise. A rotary engine is incredibly sensitive to oil deprivation, this has been the killer on most of these engines.

In a rotary, the oil must perform 3 functions:
To help cool the engine.
To reduce friction and wear of the moving parts INCLUDING the Rotor itself.
To 'Seal' the apex seals to the rotor housing (critical for compression)

It is worth noting that the Apex seal alone does not seal enough for an adequate compression seal, Oil is the key.

In order for the Oil to do all three, the oil has to be injected into the engine. This means that oil is present in the combustion cycles.

At low RPM's rotaries suffer their worst wear as the oil pressure can be dangerously low for the life of the engine, this is compounded by the fact the engine is cold.

We could then argue that in WEC and F1 the issues of Oil deprivation are even less, due to the high continuous RPM's of racing. The engines are also never started cold, so all of the pain felt by many rotary owners is solved merely by the application of racing the engine.

The next issue then raises itself as a character of the first... the Oil... what oil should we burn?
Well as you guys will know, you should NOT burn standard 10w-40 (or any) Engine oil. It is not made to burn cleanly, and no engine wants those kind of deposits in it combustion chamber!
And guess what the RX7 and RX8 do! yep! they burn ENGINE oil in the combustion chamber

Now we can see why these engines have such a bad reputation for reliability on the road, yet the rotaries that have raced seem to be absolutely fine!

To run a Rotary properly (the difference between lasting 50k miles and 150k miles) is your oil. Im going to cut this short and say, all rotaries should run either PRE-MIX or a completely separate 2-stroke Oil injection system.

2-stroke oil is designed to burn, it meets all the requirements for oil in the rotary design... and therein, is our problem.

To build an F1 rotary car you would need to:
Burn Oil. (A massive No-No today)
Use two completely different types of oil in the engine (engine oil and combustible oil '2-stroke')
Design incredible heat shielding to fit the current slim designs, the exhausts run a lot hotter than reciprocating engines.
Use a 3-4 rotor design in order to develop competitive HP levels.
Use forced induction as a side effect of cleaning up intake air pressures, as efficient NA air induction is very difficult on a rotary.

The rotary is such a catch 22 engine by design, it seems like the perfect platform for a race engine, given that it thrives on high-rpms and high heat, yet the problems running the damn thing raise far to many engineering challenges that simply out-weigh the pros of using one.

Oh, and of course... F1 regulations are far to boring to allow such fun and incredible sounding things as rotaries and nice 3litre v12's

[PlatinumZealot]

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

Piston engines are more efficient.. for now at least.
That said, if there were special F1 regulations for rotaries the ensuing focus on improving that engine, focus that was never there before at this level, would certainly result in solutions that would have been found many years ago.

The is a development on the rotary engine that solves some of the problems of Wankel Engines. This engine is not a Wankel engine though.

http://liquidpiston.com/

[mzivtins]

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

Piston engines are more efficient.. for now at least.
That said, if there were special F1 regulations for rotaries the ensuing focus on improving that engine, focus that was never there before at this level, would certainly result in solutions that would have been found many years ago.

The is a development on the rotary engine that solves some of the problems of Wankel Engines. This engine is not a Wankel engine though.

http://liquidpiston.com/

https://www.youtube.com/watch?v=0e785YnDmq0

Unfortunately that avenue of the 'Inside-out wankel' is now a complete dead end to us normal guys... the company behind it scooped a multi-million dollar contract with DARPA, so these incredible engines are now only available for US military applications. I was actually really pissed off at this!

The liquid piston engine is said to be upward of 65% thermal efficiency... incredible, what a loss!

[tuj]

Rotaries aren't in F1 for a couple reasons. 1) they are banned. 2) they use a lot of fuel. 3) they are relatively under-developed compared with piston-engines.

These 3 factors prevent the rotary in F1. That said, it won LeMans; the only Japanese car and the only rotary ever to do so.

[PlatinumZealot]

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

Piston engines are more efficient.. for now at least.
That said, if there were special F1 regulations for rotaries the ensuing focus on improving that engine, focus that was never there before at this level, would certainly result in solutions that would have been found many years ago.

The is a development on the rotary engine that solves some of the problems of Wankel Engines. This engine is not a Wankel engine though.

http://liquidpiston.com/

https://www.youtube.com/watch?v=0e785YnDmq0

Unfortunately that avenue of the 'Inside-out wankel' is now a complete dead end to us normal guys... the company behind it scooped a multi-million dollar contract with DARPA, so these incredible engines are now only available for US military applications. I was actually really pissed off at this!

The liquid piston engine is said to be upward of 65% thermal efficiency... incredible, what a loss!

Darpa scooping them up could actually be better for the techbology than waiting for the huge politics of the auto industry to give them a leg up. There are so many cool engine ideas that the auto industry never gives any chances to. I notice ideas relating to the improvemnt of the piston engine are quickly adopted but never any wholesale changes. It is sorta obvious why and you could write a book on the many reasons for this but it is just sorta unfortunate that some of the most ground breaking ideas get left by the sayside.