Probably something to do with 'losing face' - not a criticsm, just a comment. They wouldn't be the first...

I haven't, I'd like to! They are good looking, I think. However, do you mean because of the engine, or despite it? Would it be worse with one of their very nice little V6's installed?

The wankel is very much like the old 535 engine, bit gutless at first sight, but you just wring it out. A nice light V8 would be my preferred engine, noise wise. The rest of the car is Mazda quality applied to a sportscar, damn good.

Well the RX2 was a success - cheap, powerful, ultra smooth, reliable (albeit on the lower rung of the ladder) but of course it was a bit heavy on fuel which didn't matter then but the fuel crisis hit.....

Of course the RX2 had its fair share of warranty claims and there were suspect piston engines around too, but when your different the eyes upon you are much more critical.

Another thing against the Rotary was that for a long time only Mazda would do the repairs and we all know the cost of 'genuine' service - even when Mazda trained mechanics started going out on their own with realistic labour rates you could still only buy parts from Mazda and again, we all know the cost of 'genuine' parts especially if you needed housings.

I've been waiting for someone to post the pic. Looks like I'll have to do it myself...

2 interesting rotary things I've had told to me.

1. A GTP driver was running at the Daytona 24 in the heyday against the 4-rotor Mazda (beautiful car). He said the fumes coming off the car were pretty bad. Remember they were running witch's brew fuel, and that thing pumped a lot of raw fuel out the tail pipe. Anyway, he spent the last 1/2 of his stint violently puking inside his helmet. He's a tough guy...never said anything about it on the radio, just kept washing his mouth out with the drink bottle, kept driving and kept puking. End of the stint, he hops out of the car, the next guy starts to hop in and sees the mess that is _everywhere_. WTF!!!!! The second guy had to just deal with sitting in the first guy's puke. Sometimes being a driver isn't all it's cracked up to be.

2. A heavily modified prototype car that originally carried a piston engine was converted a rotary. It wasn't a complete back to back, but they did as much as they could to keep the car the same between the 2 engines. On corner entry the car was crazy loose. Apparently, the mechanical drag of a rotary engine isn't enough to lock a diff on over-run and can cause some real problems. Interesting problem that isn't completely obvious.

I remember a rotary engine F1 car was aproved in the slididing skirt days. I think the team was German and when the car was launched, the FIA
banned it that day!! You soon would realise why, when you saw the photo of the rear. It was absolutley clean!! The engine was a aluminium rectangular shaped billet, giving
a very clean airflow. The FIA is the sole reason why the rotary engine is not now the most common engine in use.
Do we think that F1 engines are Hi-Tech? Using a very bad 100 year old valve system and pistons from the same era that retrict engines to a mere 20000rpm.
Don't laugh! Look at turbines and then look at the F1 engine, it is a joke! They are still over 80% inefficient and the FIA will not allow free design engines, so we will for ever be stuck with a Donkey engine.

Wow, I just found out just this day that there is other classes of racing besides F1 and some even have no restrictions on engine at all.........

Formula One is or was the epitome of automotive design! The last huge discovery in F1 was Carbon Fibre, over 25 years ago. Where has all the innoavation gone?
I suggest that the rules for engine design simply state that it must fit in container measuring 600mm high by 600mm wide by 800mm long, when ready to install!
F1, you are going backwards! Innovate or go away.

DOF Power apparently has a rather large family.

I haven't actually seen a rotary yet in the Tractor Sled Pull comps, the epitome of "HP required" (been a couple of turbines).

Based on weight and fuel consumption I sincerely doubt the rotary would be the choice for your box

Fun car, Greg. Nice packaging. Needs some rear compression damping, however. Tramlines badly, so is tiring to drive. Engine magic - if you don't mind the fuel consumption, & provided you don't shut it down with wet plugs. The last was an experience not to be forgotten. Prone to emitting a burning smell from under the vehicle (normal, according to Mazda). Instruments quirky, but I liked them a lot.

I think that one problem with the Rotary in F1 is that nobody can work out the engine capacity the same way that Mazda does.
It needs an equivalency formula to match it to the capacity of a 4 stroke engine. (Just like a gas turbine needs an equivalency formula)

I think that's because big rotaries aren't available.

(Haven't seen too many motorcross engines either Cheapy - I remember you telling us how good they are.)

I Don't suppose you have such a photo?

I can't see how the FIA have prevented manufacturers from adopting the rotary for road cars, or for many of the racing series for which they are not responsible.

If f1 engines are 80% inefficient, how inefficient would an f1 rotary be?

Are they aren't restricted to using just one?

No, but they don't usually resort to using four or five if they're not already using a big one.

Well for starters I have said recently as is well known that 2 strokes power advantage diminishes as the size goes up, around 500cc per pot starts to balance out.

There are big rotary's around, I have seen pictures of them and for the money thats spent on those engines for tractor pulls, including forementioned turbines used, I'm sure one could scratch build one for less.

Also turbo/supercharging doesn't work out so well on rotary's, just blows the excess straight back out the exhaust port, same for a 2 stroke.

Those old donkey engines still come out on top especially when the donkey farts into a turbo.

"bad consumption and fouled plugs" yet engine is "magic"? - we are in the 22nd Century, I can't remember the last time I fouled a sparkplug this side of my CZ MX racing days (1970's 2 stroke tech).

You don't think perhaps something of that nature is also responsible for the lack of rotaries in tractor pulling?

Don't know about that, I get the feeling that the diminishing return could be combatted somewhat on a rotary, for one there is no shortage of space for multiple spark plugs and compression could be raised.

I would shoot for the "not American" factor as well in the areas that tractor pulling originated.

Mind you I see theres "Pullers" from all over the World now (Oz in-joke)

http://en.wikipedia.org/wiki/Tractor_pulling#External_links

Apologies, cheapracer, I'm a century behind you... Yes, the engine in the RX8 is a free-running gem with the equivalent of 12 4-stroke cylinders. I ws acknowledging, however, that its efficiency is way below that of a conventional engine, & it has the quirk that a quick start/stop with a rich mixture can leave the plugs permanently wet. When it happened to me the vehicle was stranded (on site, fortunately) for a few days before I gave up & called in an expert. I, too, had not encountered the problem lately, but then most of my recent vehicles have not incorporated flintlock technology.

This is a new one on me, I've always thought of a 13b as a 3.9l 6 cylinder (6x654cc rotor faces).

How do you get 12 cylinders?

If I remember correctly, 3 firings per crank revolution for each of two rotors....

Heady days when this photo was taken...Curtiss-Wright had bought up the licensing and the Wankel was going to be the Next Big Thing.

I think you all have missed the point, the rotary engine is exciting because it is different. The way the FIA set the engine rules is stupid. Why not make it free design confined to size that fits in a area of 600 wide by 600 high by 800 long?
When you look at the old poppet valve system, doesn't the rotary valve look good. Take it further and what about Ralph Sarichs orbital engine? If we are to have any R&D on engines, it will come through racing, not the road car builders, they haven't any money! The FIA have to make engines a free design.

Sorry, you and Ben are both remembering incorrectly.

This is almost 100% misunderstood and I have seen many a Friday night workshop beer argument over this.

The Rotary is the same as a 2 stroke, 1 x 360 degree crank revolution = 1 firing (per housing).

The 2 rotor Mazda Rotary is the same as a 4 cylinder, ie; 1 x 360 degree revolution = 2 firings

or as per a 4 stroke, 720 degrees = 4 firings.


Where the confusion lay is the rotors turn at 1/3 crankshaft speed but have 3 faces so thats where the 1 fire for 1 crank revolution comes from - or 3 crank revolutions to complete 1 rotor revolution (= 3 firings).

I'm over it.

err because it would have about 2500 hp.

All things different are exciting, many here are as children when it comes to engine concepts.

That doesn't make them good.

The Orbital engine suffers the same as any other rotary - I met Ralph Sarich at the Melbourne Motor show maybe 1974? at his stand there and boy was I one excited teenager to see it turning away (a cutaway engine). The Pritchard Steam Car ( A Holden Torana with leprosy, horribly disfigured ) was also there and that was a running car as was the radio voice controlled Holden Monaro that eventually got away from him and ran a few people over Ahh, the 70's were great fun, dangerous but fun!!

You're absolutely correct, cheapracer: http://en.wikipedia.org/wiki/Wankel_engine



Well.. much more correct than I was, anyway (apparently):

Don't sweat it Dave, I've seen the best confused about the Rotary's characteristics

Hmm, I wonder if a "big block", something in the order of 2000cc, Rotary for the performance boys might be a good seller...

By the way, the Suzuki RE5 was a great bike and very reliable but it didn't sell because it was slower than the superbikes around at the time and it was different. Rode one once and it was silky smooth but very little different to the silky smooth 750 Waterbottle (750cc, 3cyl, 2 stroke).

http://www.suzukicycles.org/photos/visitor..._engine_700.gif

I always figured it was the looks as much as anything that did the RE-5 in.

http://www.delsmotorcyclesandtyres.co.uk/g..._serialNumber=2

That's a first series with the 'rotary' styled instrument cluster, the second series was much more conventional. They didn't look much different than a Waterbottle to me, probably because both have the big radiator up front and similar overall shape/colours.

Did the Sarich Orbital engine ever run? Was it ever capable of running? Or was it a scam designed to make Ralph a rich man without ever actually doing anything?

I personally believe that counting revolutions of the eccentric shaft is a red herring in this instance. If I took a 2lt 4 cylinder motor, removed the standard crank and rods and hooked some sort of Heath Robinson device which made the crank turn at half (or double) the speed, does that change the capacity of the engine? Does that make it a 2 or an 8 stroke? No it's still a 4 stroke and it's the same capacity.

The only logical way to look at it is to measure the total amount of air the engine pumps before all the combustion faces have completed a cycle (assuming 100% VE).

errr, ummm, errr, ahhh, where did anybody mention capacity?

A Rotary in one turn of it's crankshaft completes one set of the 4 effects required to produce a completed power cycle as does a 2 stroke. This doesn't make a Rotary a 2 stroke, it makes it a Rotary cause thats what it does - rotates.

The 2 stroke is called that because it creates it's completed power cycle in 2 strokes of the piston, ie; 1 down stroke + 1 up stroke.

FYI there is in fact an older engine that turns it's crank at half speed but through a system of levers it still requires 4 strokes of the piston to complete one power cycle therefore it is still a 4 stroke even though the crank only turns one revolution in comparison to the 4 stroke we commonly know that turns 2 revolutions or 720 degrees to produce one power cycle. Anyone remember this engine I would be grateful.

To suggest that a Rotary should be allowed to be judged on 3 of it's power cycles comprising 3 crankshaft revolutions in comparison to others is ludicrous.

Thus allowing the two-stroke to obtain twice the inefficiency of conventional four-stroke designs.

I believe this argument was stimulated initially by my throw-away remark that the RX8 engine had the equivalent of 12 4-stroke cylinders. You corrected my woolly memory by pointing out correctly that this was not the case because the output shaft rotated at three times the speed of the rotor. Ben then pointed out that the rotational speed of the output shaft was immaterial when seeking an equivalence with a conventional reciprocating engine. That view has merit, I think. To quote from the Wikipedia article I linked earlier:
again:

I recall that the UK licensing authorities class the RX8 as a 2.6 litre engine.

Going back to my original remark, I think that it stands or falls by the rotational speed the tachometer is calibrated to indicate. If it is the eccentric shaft speed then I am wrong. But if it is the rotor speed, then my remark has some merit, at least. I no longer own an RX8, but my failing memory suggests that at idle, the engine hummed away at an indicated 750 rpm, sounding quite unlike a four cylinder conventional engine. Sadly the Wikipedia article is unenlightening. Perhaps somebody else would be able to arbitrate. Either way, the RX8 engine is still a gem, in my opinion, if a thirsty one. Oh, & the rear axle still needs more compression damping.

There is strong logic in your post.

A 1 litre 4 stroke engine must complete 2 revolutions to displace its 1 litre rating. A 1 litre 2 stroke must complete 1 revolution to displace its 1 litre rating. In each case all cylinders must complete exactly ine cycle. So for the typical Wankel the eccentric shaft needs to turn 3 times for the rotor(s) to complete one cycle and each rotor face to complete one 4 stroke cycle. During these 3 rotations of the output shaft the typical 2 rotor Wankel will fire each of its six faces once. The correct displacement of the engine is the volume swept during these 3 rotations.

Works out to 3.438 litres for a 12A. These are quite large displacement engines in a small package.

Ha-ha
Reading the thread title I thought it's about This rotary engine
and also
http://www.youtube.com/watch?v=BQa0HQYUSGk

Which one, the original or the two strokey thing with DI? The latter certainly runs, I had a go in one of the fleet they built. Pokey.

You seem confused, 3 turns = 3 cycles not one, you even say it/contradict it yourself right here.

By your logic a 2stroke is infinite because it is always preparing for the next firing within a current stroke.

The eccentric shaft turns 3 times for 1 turn of the rotor.

1 Thermodynamic cycle of the 2 stroke = 1 turn of the output shaft.
1 Thermodynamic cycle of the 4 stroke = 2 turns of the output shaft.
1 Thermodynamic cycle of the Wankel = 3 turns of the output (eccentric) shaft.

Also interesting - the high speeds we all attribute to Wankel engines are a myth. When the output shaft is turning at say 9,000 rpm, the engine is only completing 3,000 thermodynamic cycles per minute - equivalent to a 4 stroke piston engine at 6,000 rpm.

I meant the original rotary like engine. Ralph sold the idea to investors and became a very rich real estate tycoon. The later 2 stroke engine was built by the "Orbital Engine Company" but it was not an "orbital" engine, it actually worked!

There was at least one working orbital engine. IIRC Phil Irving was present at one demonstration and pointed out several serious flaws in the design. I bet Ralph really appreciated that.
I'm old enough to remember Sarich and the orbital on the ABC TV show "The Inventors". The orbital might never have been workable but Sarich seems to be quite a shrewd businessman as well as a bright engineer; the publicity he got from the TV appearances certainly wouldn't have hurt his career.

A diagram of the Sarich Orbital, for the foreign lot who haven't seen it before.



The middle bit wobbles around and makes the rectangular chambers change in volume, etc.

Your still confused,

At 9000 rpm the Rotary engine is completing 9000 firings which means it is completing 9000 thermodynamic cycles - how else could it fire 9000 times? (per rotor housing of course). It's true that the rotor is turning 3000 rpm if you disclude the fact that the rotor isn't revolving around a fixed axis. Does anyone know what you call that by the way?

Oh it's an orbital revolution apparently! Now why didn't Ralph use that one?!

Per single turn of the crankshaft of a Rotary engine you get one firing. A Rotary's design and layout doesn't allow for the equation of 3 crankshaft turns for 1 firing in the real world - it may just not run! It has a Reuleaux triangle shaped rotor in a epitrochoid shaped housing for the purpose of actually functioning as a whole, not a third.


Anyway, People can decide for themselves...

Your still confused,

At 9000 rpm the Rotary engine is completing 9000 firings which means it is completing 9000 thermodynamic cycles - how else could it fire 9000 times? (per rotor housing of course). It's true that the rotor is turning 3000 rpm if you disclude the fact that the rotor isn't revolving around a fixed axis. Does anyone know what you call that by the way?

Oh it's an orbital revolution apparently! Now why didn't Ralph use that one?!

Per single turn of the crankshaft of a Rotary engine you get one firing. A Rotary's design and layout doesn't allow for the equation of 3 crankshaft turns for 1 firing in the real world - it may just not run! It has a Reuleaux triangle shaped rotor in a epitrochoid shaped housing for the purpose of actually functioning as a whole, not a third.


Anyway, People can decide for themselves...








Hi tech lingo......

If you observe some air being drawn into a chamber (suck) then watch that same parcel of air go through it's squeeze, bang and blow, you will find that the rotor has turned 360 degrees. Meanwhile the eccentric shaft has turned 3 revolutions. That is one thermodynamic cycle. Of course that rotor has fired 3 times - it has 3 chambers!!

Fixed axis or not - when the rotor has rotated 360 degrees it is back in its original position with the same chamber at TDC compression or wherever it started.

Sure people can decide for themselves but they will be either right or wrong.