Wankel - will it return?

[forddeliveryboy]

 

Brilliant idea, up against the reciprocating piston engine with a few years more development behind it. Mazda last made one in 2011, emissions were getting expensive to sort. Will we see it again?

 

[Bear]

Yes. It's part of the Frazer-Nash range extender system, and IIRC Audi e-Tron was originally going to use it but not sure now if that is the case, as Frazer-Nash are obviously pitching it to people somewhat optimistically.

 

Realistically an LPG-fuelled Renesis six-port with rotor lubrication should be cleaner than most options, and with a generator system geared to allow it to run at high RPM for optimal efficiency (remember that road cars need to operate at low RPM too - this is the major source of emissions issues on the rotary, the tip lubrication is a tiny demand on the oil) the smooth nature of the engine and compact dimensions would allow underseat packaging (which I believe the Audi concept went with). Not so much a range extender as a fuel cell.

 

The issue with the engine in current installations is that it can't pull tall gearing. Why do diesels give such great economy? Torque. 1.6 diesel can pull 28mph/1000 rpm easily in something like a small hatchback - and look at what Volvo manage to haul with just a 1.6. Rotary engines are still used in prop planes because the thing is designed for prolonged high RPM running.

 

Hybrid is the answer in many ways. Urban traffic handled by plug-in electrics with 40-60 mile range, rotary drivetrain that cuts in at motorway speeds, ideally paired with a smart CVT.

[SamR380]

Not quite as nice as a Cosmo, but Mazda are supposedly putting a rotary in this:

 

 

A 300cc-ish single rotor. I would love to see that engine, so many things I could do with it.

[Asimo]

I doubt it will return to conventional cars. The Wankel has an unsurmountable problem: the combustion chamber is a poor shape which causes a large loss of heat from the burn and therefore reduced thermal efficiency, aka economy.

 

It may well have a future as a replacement for Clark cycle two strokes in chainsaws and other weight critical applications, including the above range extender.

[Tamworthbay]

Yes, in a VW that has zero emissions and does 90 to the gallon, at least that's what their marketing man told me.

[martc]

They've not gone away - at least in the aircraft industry (gliders and un-manned drones in particular).

 

Austro Engines in Austria make them - http://austroengine.at/en/home1

 

Just noticed their address is "Rudolf Diesel-Straße", there has to be a joke somewhere in there.

Edited September 27, 2015 by martc

[capsuleboy]

Hopefully the one in the boot of my Avantime will make a comeback, into the engine bay of the recently purchased Ro80.

Wish me luck!

[New POD]

I was looking at an RX8 for £500. Needs an engine Recon. £2500 for 280 BHp plus £500 for the car, sounds great, until you look at fuel consumption. Ideal for a hybrid though. Maybe.

[D Spares & Tyres]

Stick a ford v4 it...

[MarvinsMom]

sadly i don't see the wankel engine ever coming back in a mainstream car.

 

hideous fuel consumption, poor emissions and that is before thinking about the inherent problems with the engine such as rotor tip wear.

 

it seems all the RX8's for sale have a shagged up engine, which is a shame as it was a proper nice car, and different with it.

[Junkman]

Stick a ford v8 in it...

 

FTFY

[Bear]

sadly i don't see the wankel engine ever coming back in a mainstream car.

 

hideous fuel consumption, poor emissions and that is before thinking about the inherent problems with the engine such as rotor tip wear.

 

it seems all the RX8's for sale have a shagged up engine, which is a shame as it was a proper nice car, and different with it.

 

Can't speak for the six-port, as I didn't own one, but as a former 192 four-port owner, "poppycock".

 

The fuel consumption on mine averaged at 26mpg - it was capable of hitting mid 30s on good runs, which for near 200bhp and a swept volume comparable to a (very wide bore, short stroke) 2.6 six pot isn't bad. Particularly the way I drove that thing.

 

Rotor tip wear isn't that big an issue on the recent Mazda engines. The oil injection system does help, but simply the materials are at the point where without forced induction, you should hit 200,000 miles before rebuild. That's 200,000 miles without timing belts or chains to worry about, and a super small, light engine to work on when they are due.

 

(Oil consumption on mine was also much less than the 1.6 New Beetle that preceded it).

 

That bit over - yes. Most used RX8s are cheap shagged ones with faults. There are a number of issues that surfaced - top one was corroding oil cooler pipes. Unattended... you can imagine the consequences. RX8s also had gearbox issues on the 231's six-speed, and they rust - two, three year old cars were showing rust on sills, the solution to which was to put some clear sticky plastic on it. Quality.

 

Driven like a normal car, an RX8 will fuck up. You have to warm them up respectfully, then cane the bastard until it screams (or buzzes). If you don't beep your RX8 every drive, then one, you have no soul, and two, you're not getting the breathing and oiling right. The plugs will foul, the car will sulk, and the owner will crank the thing half to death, burn out the coil packs, wreck the starter, etc.

 

All of these things, and more, are why I had a new RX8 with a warranty but haven't gone back for a secondhand one, and are also why I'm seriously tempted by the bargain "won't start" ones - they are simple machines and just very misunderstood by the generation of owners that had the chance of a sporty RWD coupé on their company car sheets thanks to the four-door config. Drive it like an A4 TDi and you will kill it.

[Angry Sheep]

Apparently Mazda's going to unveil a rotary-engined sports car concept at Tokyo. GR9 pic.

 

 

http://www.motoringresearch.com/car-news/tokyo-motor-show/mazda-teases-new-concept-sports-car-ahead-of-tokyo-debut-0930997408

[MarvinsMom]

I dunno, 26-30mpg sounds pretty shit to me.

 

the xj6 runs in at 21-24mpg and that a 4 litre six.

[dugong]

I dunno, 26-30mpg sounds pretty shit to me.

 

the xj6 runs in at 21-24mpg and that a 4 litre six.

Yeah, and that's a real powerhouse*.

[Bear]

It's not shit, it's not great. And the way the power is delivered is very different, and in a much lighter package for weight balance. Shit is a 1.6 VW returning 30mpg. Or my last MX5, also a 1.6, which I'm sure was wonderful on short slow journeys but returned a scarcely believable 28mpg at motorway speeds. Which were also very, very tiresome. Car in wrong environment not efficient shocker, I know.

[Bear]

Yeah, and that's a real powerhouse*.

 

It's got more than the RX8, particularly in torque, but it's in a heavier, slower package. A Jaguar XJ6 powered by a rotary would be... unpleasant (unless they resurrected the 20B. Now, if you want bad economy...)

[dugong]

It's got more than the RX8, particularly in torque, but it's in a heavier, slower package. A Jaguar XJ6 powered by a rotary would be... unpleasant (unless they resurrected the 20B. Now, if you want bad economy...)

Not for the capacity, it hasn't. Torque, certainly.

Jags in 'I don't really get them, they're a bit tragic' shocker.

[Bear]

No, it falls over on bhp/litre, but then the RX8 is also outclassed by the S2000 on that regard, no? 2.0 and 240bhp without forced induction? Similar appetite for fuel & oil, too, IIRC.

[garbaldy]

The old man always used to say you can't have power without burning fuel,

Anything that manages over 20mpg while being reasonably powerful and a bit of fun gets my vote, but then I'm the numpty who removed a wanker and stuffed a veight in its place.

[Lacquer Peel]

Remove Wankel, insert RF supercharged diesel.

RX-8s are great looking cars and mechanically interesting but I don't think it's unreasonable to expect "get in and go" reliability from a non-exotic car.

[Bear]

Depends on how you define exotic. RX8 will run rings around a Porsche 968 on the road and there's not much in it on the track - exceptionally good handling and brakes and a really involving car to drive - and they were being flogged at £17,500 when the massive oversupply causes by backlog orders and the factory fire landed in the UK.

 

Offering a very purposeful and effective sportscar for £17K instead of £50K doesn't absolve the buyer of using the damn thing properly.

[MarvinsMom]

oh i dunno, jaguar says that the xj6 originally had 322bhp (its the supercharged one), now i dunno how many of those horses have gone lame, bolted or been shot in the last 20 years, but that is more than enough horseys for me.

[Bear]

The 4.0 without the blower is 245bhp. That's only a little less than the XJS HE 5.3 V12 - and probably weighs a bit less even with the overall weight of the cars making engine weight almost irrelevant.

[Junkman]

that is more than enough horseys for me.

 

There is no such thing.

[dugong]

oh i dunno, jaguar says that the xj6 originally had 322bhp (its the supercharged one), now i dunno how many of those horses have gone lame, bolted or been shot in the last 20 years, but that is more than enough horseys for me.

So your engine, with nearly twice the equivalent capacity of the Wankel, with a power adder, has more grunt? You don't say. 21-24 mpg is pretty impressive for that level of performance, but I bet the second you jump on the loud pedal the petrol pisses away. You'd probably get that from a gentle motorway run though.

[MarvinsMom]

i've no idea what torque the aj16 will develop,

 

 with sport on and the pedal buried in the carpet the trip computer, which is faultlessly accurate* has been down to 3mpg.....

 

the 21-24mpg was an overall figure and was a mix around town and also a steady 75ish on dual carriageways and motorway.

[Lacquer Peel]

That's terrible* when a modern diesel with similar power can average 50MPG.

[MarvinsMom]

i knew it was a thirsty old thing when i bought it.

 

the xj6 was never an efficient car, it is not intended to be.

 

the £90 odd each week in fuel i was putting in it was tiresome, but the journey was alway very agreeable.

 

very agreeable indeed. 

[Bear]

i've no idea what torque the aj16 will develop,

 

 with sport on and the pedal buried in the carpet the trip computer, which is faultlessly accurate* has been down to 3mpg.....

 

the 21-24mpg was an overall figure and was a mix around town and also a steady 75ish on dual carriageways and motorway.

 

Seems fair, my 340bhp Chrysler that weighed 2 tonnes anna bit (plus lardarse in the driver's seat) gave 33mpg at 75 cruise control (36 in the 50s) and an overall of 24mpg - though I didn't cane it on narrow roads, no fun. 5.7 litres and a lot of torque. Just being slightly brisker got it down to 18mpg, the same sort of brisk I do in the SLK (progressive power, but not kickdown/mindless hoofing it out of every 30) and still get over 30mpg with.

 

RX8's biggest issue was the tiny tank. You notice filling up every 250miles more than you do putting twice as much in every 500, for some reason. A problem it shared with the Legacy 4Cam Turbo I had; even the Jazz 1.4 had a stupidly small tank.