Rotary engines?

[Dirk]

1. Can anyone explain to me why they are not at least as prominent as piston engines?
2. Are there any air-cooled rotary engines?
3. Are there any rotary engines that would fit into a beetle without cutting the body?
4. Are there any rotary engines that would fit into a Type 3 without cutting the body?
5. Where can one purchase a reliable rotary engine?
6. What does a rotary engine at such a supplier normally go for?
7. Are rotary engines less efficient than piston engines? Why?

[Blitzkrieg]

4. Are there any rotary engines that would fit into a Type 3 without cutting the body?

Yup, fits underneath the stock engine cover in a Type 3 - Have seen a fasty with a 13B conversion done and it was ultra neat

[BARON]

Sarel, Im not an expert but a big fan of the rotary.
Here is my views and Im sure Bugger the expert can comment on it.
The engine does not have valves which can force seal the inlet ports at a relative early stage of compression stroke like the piston engine --You can say compression start only after the inlet port is fully closed with some mixture being pushed back into the inlet manifold which means a slightly smaller volume . With a turbo/supercharger you can somewhat prevent or delay this outflow plus of cause the extra charge you force in .
This is the same draw back as the 2 stroke engine. If you could fit valves you could increase the volume and compression ratio.
The same problem appears on the outlet side where your outlet gas slips around the apex seal while moving over the outlet port and ending on the inlet side . This dilute the fresh inlet gas with exhaust gas.
Compression ratio is in the order of 7or8;1
The effectiveness of the seals is not as good as the cicular rings of the piston engine
The combustion chamber is thus less effective than the cylinder engine s chamber but you have 3 compression events per revolution appose to the one compression event in the piston engine.
A fuel injection can improve performance and economy
Size is and weight---
About 162 kg for the Mazda 12b (which is almost a first generation engine and outdated) the size 790mm x 550mm x 650mm
The 3 rotor newer generation is bigger
BUT---
The rotary can be force filled (turbo/supercharger) and 1000hp is possible from the 3 rotor Mazda engine This is done in drag racing in America
You also have an almost perfect " green engine " where it can be converted with little mods to hydrogen fuel
These engine are also being used in micro light aircraft and small industrial engines
O and there was a air cooled producton engine The last DKW m/cycle engine about 1972/3
cheers baron

[Dam]

You get a Hercules motorbike that uses a Sachs Rotary engine

[beetlepower]

...they belong in dem Mazdas...that is all I know

[fig]

There was also a rotary-engined Suzuki motorcycle in the 1970s.

In addition to all of BARON's reasons, the difficulty of sealing the rotor reliably has always been a big problem with rotaries, although modern materials have made them more reliable. High fuel consumption is also an issue. In fact, in the late 60s and early 70s, most motor manufacturers were experimenting with wankel engines, but that all ended with the 73 oil crisis.

[karmakoma]

and even today Mazda's RX-7 has much higher fuel consumption than other vehicles in its class. The other problem is a relative lack of torque vs the power produced (compared to 4-stroke engines and especially vs turbodiesels).

[Bugger]

1. Can anyone explain to me why they are not at least as prominent as piston engines?

As Masdo bought the original rights to the motor and developed it

2. Are there any air-cooled rotary engines?

Not that I know of but there are actually quite a few different Versions of other inventors of the rotary motor just search different convigurations of rotaries

http://www.google.co.za/imgres?imgurl=h ... CCkQ9QEwBA



3. Are there any rotary engines that would fit into a beetle without cutting the body?

Fitting a rotary is actually one of the conversions you do not need to cut the engin bay of a but to fit
We just cut to make it easier to work on
The only body part that needs to be cut is the front to fit the radiator


4. Are there any rotary engines that would fit into a Type 3 without cutting the body?

Same as the beetle but Blitz is wrong when saying the engin lid closes on a fast back
The BOOT LID closes but the engin lid , can not close

5. Where can one purchase a reliable rotary engine?

From the importers but you have to know what to look for and how to check it when buying
But 90% of the time the 13Bturbo motors that are imported has less than 60 000Km on them
And when you buy always try and buy a motor with a flex plate on , which mean it came out of a automatic Vehicle and was not hammerd as hard as a N/A and it has a Counter weight on which is needed for a conversion in to a Beetle

6. What does a rotary engine at such a supplier normally go for?
R6500-R8500 for a series 4 or 5 motor
R10 000 for a series 6 motor twin turbo
R12-15 000 for a series 6 Cosmo RE twin turbo motor Which has very nice big ports already Then you chuck the twin turbo setup off
And fit a T76 turbo on and make easy 220Kw


7. Are rotary engines less efficient than piston engines?

NO

Why?
The rotary has much more compression strokes in one crank revolution than a 4stroke piston engin
Again just Google rotary vs 4stroke and there are sumulations on you tube showing the differance

Oom Baron
the metalurgy boffs at Mazda have done wonders with the new type seals and springs they use on the newer generation motors
The potoriecans boost these motors nearly 3.5 Bar nowadays

My motor is currently again by my Mate Arthur Joubert from AJ Racing for some upgrades they Dyno`d a series 6 The other day making 435KW on the wheels it was insane hearing this thing on the dyno and was a street car with a Turbo costing (No Bull shit)R28K

[sarel.wagner]

Holy smokes Batman, ask them to bri ng it to the Pretoria show on the 1st please man

Rgrds

[BARON]

I wonder how many guys here have got them in their cars

Yes I must say after I wrote about the reliability issue I thought about the fact that they won the Le Mans 24 hour endurance race a few times, ha the French had to change the rules to keep them out. But there was a big issue with the seals on early engines.
The engine is small and compact and in my opinion the best replacement fit for a vw, and for normal use there are enough torque
Something I read about fuel economy is that the turbo engines are better on fuel consumption than normally aspirated ones –if used in a normal way.
In the 90s there was a guy in Johannesburg claiming that he found the secret to good fuel economy His delivery truck with rotary got 12-13 km/liter in city traffic. Now that is good in my books if you consider that from a engine with small 6 cylinder type performance . I tried to hunt him down for his “secret” but he disappeared.
The other thing to remember is that the quoted hp by Mazda is normally in Japanese horses (JWIS ) which are much smaller than our horses .But I agree with bugger these things can be tune to massive hp. And the faster they spin the smoother they get.
Its worth fitting to your car just for the damn sound of it
Norton also produced an a/cooled rotary m/cycle and there were boat engines as well as lawn mower engines in the USA
cheers baron


.

[Dam]

I have a NSU Ro80 with it's original Felix Wankel motor, heavier on oil than fuel, smokes more than a Rasta

[BARON]

Dam ,
Dam you are lucky ,wish I can get my hands on one because thats where it all started.
A guy once tried to sell me one with a Ford v4 engine. He was convinced that it was a Wankel engine--because the dealer sold it to him as Wankel and he believed the dealer. Yes they were not the best be the pioneers.
Am I correct that the Wankel set up was taken over by NSU who then became part of the Audi group ( one of the circles in the Audi emblem )
Wasnt there a Wankel jeep somewhere in the past--something like a buggie thing---

Dam you must show us your collection af vehicles one day.
cheers baron

[hitlers revenge]

Baron see here....

http://en.wikipedia.org/wiki/Auto_Union

[BARON]

Thanks HR
I once owned a DKW1000s and must say it was a very very nice car although not to economical compared to cars of its size.
I even wonder how a 1000 s whould have performed with a rotary engine.
Hubcap what are your opinion on the idea of a 1000s or F102 with a rotary
cheers baron

[Dirk]

Thank you all for your answers.

My curiosity started when I found some youtube videos, explaining how a rotary engine works.
I must admit that I believe, pound for pound, that a rotary would make for an incredibly good substitute for
a type 1 engine.

Yes, the car won't be original, but you'd probably get better performance and better fuel consumption.

And at the prices mentioned... it might be worth it.

My biggest concern though, is the cost of fitting and changing all the cooling bits to get it all gelling nicely.
Something I'll keep in mind if I ever decide to get a beech buggy