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piledriver
05-24-2003, 11:58 PM
Anyone has something to tell about the Wankel Engine???

something in favour, or against...

I think it is a good engine...

cobrapower
05-25-2003, 12:50 PM
I think that the Wankel engine, is quite a design. Rotary engines are very good once you can engineer out the problem of low fuel economy. (first engines had terrible fuel economy). For example, one of the few Japanese cars that i like, the RX-7 had the rotary engine, i think that it provides an ample amount of power to work with and allows for some decent work to be done to the engine.

Kudosdude
05-27-2003, 05:32 AM
Click here (http://travel.howstuffworks.com/rotary-engine.htm) for wankel details.

piledriver
05-28-2003, 04:07 AM
To me, this rotary engine looks great!
With the nowadays technology, the early encounterd problems such isolation and others, can be easily solved...
With such compact size so much horsepower can be developed.... and with less vibration and much more reliability...

Kudosdude
05-28-2003, 05:13 AM
With the nowadays technology, the early encounterd problems such isolation and others, can be easily solved...

LOL :D I wish it was that simple !!!
It has taken a VERY long time to develop the rotary engine. It's one of those designs that looks fantastic on paper . . . but as with all things it is NEVER that simple.

Hats of to mazda for sticking with it.
Tuning a rotary is ridiculously difficult . . . bring on jet turbines that's what I say ;)

piledriver
05-28-2003, 07:07 AM
Originally posted by Kudosdude
LOL :D I wish it was that simple !!!
It has taken a VERY long time to develop the rotary engine. It's one of those designs that looks fantastic on paper . . . but as with all things it is NEVER that simple.



I know itīs not so simple or trivial the development of such engine or upgrades for it, and I do that it costs a lot...
But I think a technology like this, must be researched because of it advantages...

And I donīt think a engine that has about 200 hp/ litre needs turbos or superchargers or anything else...

DSM owner
05-29-2003, 07:14 AM
I think it's currently useless. The only advantage it has over a 4 cycle reciprocating engine is weight and it's not a big difference. Putting a Ford 302 into a n/a second gen RX-7 increases weight by about 100 lbs, yet increases power by about 100 hp and increases torque by almost 200 ft lbs. The Ford will be more reliable, cheaper, and last longer. If you put a 302 into a turbo RX-7 the weight increase will barely even register.

piledriver
06-02-2003, 06:16 AM
Originally posted by DSM owner
I think it's currently useless. The only advantage it has over a 4 cycle reciprocating engine is weight and it's not a big difference. Putting a Ford 302 into a n/a second gen RX-7 increases weight by about 100 lbs, yet increases power by about 100 hp and increases torque by almost 200 ft lbs. The Ford will be more reliable, cheaper, and last longer. If you put a 302 into a turbo RX-7 the weight increase will barely even register.

A big advantage is its reliability, because the slow movements of the inner parts of the engine and the low vibration, thanks to the only rotor that gives the motion...

DSM owner
06-02-2003, 10:34 AM
Originally posted by piledriver
A big advantage is its reliability, because the slow movements of the inner parts of the engine and the low vibration, thanks to the only rotor that gives the motion...
Um..... the cars that have come with rotaries in the past have had very poor reliability. In all previous Mazda RX models, the apex seals (they are like piston rings for a rotary) wear out quite frequently(under 100,000 miles, alot of the time). It's over $1000 just for the parts when these break, and if you're paying someone else to put them in the price is outrageous. Meanwhile any American V8 or Japanese 4, 6 cylinder can go 200k miles with no internal engine work.

piledriver
06-03-2003, 04:03 AM
Originally posted by DSM owner
Um..... the cars that have come with rotaries in the past have had very poor reliability. In all previous Mazda RX models, the apex seals (they are like piston rings for a rotary) wear out quite frequently(under 100,000 miles, alot of the time). It's over $1000 just for the parts when these break, and if you're paying someone else to put them in the price is outrageous. Meanwhile any American V8 or Japanese 4, 6 cylinder can go 200k miles with no internal engine work.

well, everything I said before is based on theory, because Iīve never seen a rotary engine before... just read about it...

Kudosdude
06-03-2003, 05:12 AM
Don't believe all you read, especially if it is from the Mazda website. (P.S. Every-one should have driven a non-turbo wankel at least once, it's more important than your first drive in a Ferrari IMO)

Rob
06-03-2003, 08:12 AM
Originally posted by Kudosdude
Don't believe all you read, especially if it is from the Mazda website. (P.S. Every-one should have driven a non-turbo wankel at least once, it's more important than your first drive in a Ferrari IMO)

What's so special about driving a wankel engened car?

piledriver
06-05-2003, 05:13 AM
Did you see that the RENESYS rotary engine of the Mazda RX-8 is the best international engine of 2003??
:D

206_HDi_WRC
06-13-2003, 09:34 AM
The wankel rotary engine is simply a masterpiece of automotive engeneering.
However, some of the presente rotary engines still remain with the problem of high consumption of oil, as also fuel.
The rotary engines have a smoothly sound but when it takes to rev's highther their sound like a beast.
Rotary engines can support high rpm's near to 8500rpm's is the maximum till now.
The rotary engine is fitted with 2 rotors in eliptical shape.
Each one of the 3 faces o f the rotor can have nearly 700cc in maximum depending in the size o f bore and stroke, which allows to produce a high amount of power with less cc.

DSM owner
06-16-2003, 05:25 AM
Originally posted by 206_HDi_WRC
The wankel rotary engine is simply a masterpiece of automotive engeneering.
However, some of the presente rotary engines still remain with the problem of high consumption of oil, as also fuel.
The rotary engines have a smoothly sound but when it takes to rev's highther their sound like a beast.
Rotary engines can support high rpm's near to 8500rpm's is the maximum till now.
The rotary engine is fitted with 2 rotors in eliptical shape.
Each one of the 3 faces o f the rotor can have nearly 700cc in maximum depending in the size o f bore and stroke, which allows to produce a high amount of power with less cc.


Rotary engines don't have a bore or stroke......

I don't see how consuming alot of fuel and burning oil makes it a masterpiece of engineering...

piledriver
06-23-2003, 09:02 AM
the old generations of the rotary engine did that things, but the new ones, like the RENESYS from Mazda, is known as low comsuption, and low emission levels...
thatīs why is a masterpiece...

MKielbasa
06-23-2003, 07:57 PM
Originally posted by piledriver
the old generations of the rotary engine did that things, but the new ones, like the RENESYS from Mazda, is known as low comsuption, and low emission levels...
thatīs why is a masterpiece...

The new renesys is better than the old wankle in those area's beacuse they moved the exhaust and intake ports.

Rotary engines do not have valves, in the origonal design both the intake and exhaust ports were exposed to the current combustion chamber, this caused fresh fuel to be blown out the exhaust before even going through a compression/power cycle.

They also managed to re-engineer the apex seals, and claim they will not longer be a problem. That is also what they said about the 13B rotary, and that didn't go over to well.

To be a practical engine for a passenger car (read: Not 2300 pound car) they need to be turbocharged, or be 3 or 4 rotar N/A engines. The RENESYS design makes it impossible to have more than 2 rotars, therefore it MUST be forced induction to be usefull in a daily application.

The problem is torque. The RENESYS only puts out around 150 pound feet or torque. A rotary produces its massive power by revving to extreme RPM. The RENESYS has been tested at over 10000 RPM. These types of power bands are great for carving canyon roads, but useless for day to day driving.

THe other problem is the general public. Rotary engines are extremely hard to tune. They also have a tendancy to explode over the slightest ping. The general public cannot be expected to maintain their vehicle in perfect show room condition. People like to just put gas in their car and forget about it. You cannot do that with a rotary.

piledriver
06-24-2003, 04:43 AM
As I know almost nothing about engeneering, I didnīt know such informations you told... and it is quite relevant to say if this engine is or not worthwhile...

MKielbasa
06-24-2003, 07:11 AM
Originally posted by piledriver
As I know almost nothing about engeneering, I didnīt know such informations you told... and it is quite relevant to say if this engine is or not worthwhile...

It will be a great powerplant for the new Miata, but unless they impliment some new design changes, I think the rotary will die once again.

You know, it would also do very well with an electric assist motor to beef up the low end.

piledriver
06-24-2003, 09:07 AM
Originally posted by MKielbasa
It will be a great powerplant for the new Miata, but unless they impliment some new design changes, I think the rotary will die once again.

You know, it would also do very well with an electric assist motor to beef up the low end.

What do you mean with low end??
torque???

Kudosdude
06-24-2003, 09:18 AM
Yup.

Interesting idea that; not practical, but interesting nonetheless.

piledriver
06-27-2003, 07:33 AM
How does this electrical assist engine will help the low end???

Venon
10-31-2003, 04:30 PM
:D :D

crisis
11-05-2003, 11:26 PM
The rush by manufacturers worldwide to adopt this technology is evidence enough of its value. Mazda have spent millions to develope it and one must ask why. All I can think of is that is physically small for the power output. The value of this is somewhat reduced when you look at the torque, because it still needs to be put in a fairly light car to be effective. therefore a turbo four will do everything and more. Mazdas answer may be in its self imposed exclusivity and the loyal following the technology has by its adherents.

fpv_gtho
11-05-2003, 11:54 PM
i reckon that if mazda hadve stopped at the RX-3 and kept that instead of going right up to rx-7, the engine would be more popular.

crisis
11-06-2003, 10:58 PM
If Mazda stopped with the RX3 we wouldnt be talking about Rotaries in the present tense.

fpv_gtho
11-06-2003, 11:03 PM
im more or less talking about keeping the rotary in cars of similar size to the RX-3. today that would be like having a renesis MX-5

crisis
11-06-2003, 11:30 PM
Originally posted by fpv_gtho
im more or less talking about keeping the rotary in cars of similar size to the RX-3. today that would be like having a renesis MX-5
I would still rather a turbo 1.8lt 4 than a rotary. So would most of the rest of the world it seems.

megotmea7
11-07-2003, 02:06 AM
I would still rather a turbo 1.8lt 4 than a rotary. So would most of the rest of the world it seems.
only through miss information and the general concensus that rotarys are "unreliable" and put out no torque. the FD put out plenty of torque and with a redline of 8krpm you can gear for more torque and your argument becomes pointless, rotarys are performance engines, they make great power from a small size and small displacement, when you say youd rather have 1.8 liter 4 than a rotary what about a 2 liter 20b 3 rotor? you want torque? lmao and thats closer to the displacement than the 1.3 liter 13b-rew, compare ANY 4 cylinder to the 20b in terms of reliability modability, performance(and keep in mind it came in a luxury car...) and if your worry'd about gas mileage then i wouldnt even be worry'd about a performance car. gas consumtion is the killer of the rotary in the 80's if it wernt for the ga crunch you be seeing rotarys in everything. after the gas crunch GM and mercades droped their projects, mazda was the only one to stick with it and if ppl can get over the misconseptions and see the truth i wouldnt doubt other manufacturers would start toying with it again. on paper the design is almost perfect(more perfect than any piston engine, only thru use of better materials and developent it will come to blossom(the piston engine has been around forever, if the rotary had as much development as piston engines we wouldnt be talking about it in the current context.

PS i read thru this whole thread and theres so much ignorance im not going to bother with responding to, even if i did most these ppl arnt even around anyway...

fpv_gtho
11-07-2003, 07:08 AM
Originally posted by megotmea7
gas consumtion is the killer of the rotary in the 80's if it wernt for the ga crunch you be seeing rotarys in everything. after the gas crunch GM and mercades droped their projects, mazda was the only one to stick with it

theres a good side and bad side to this:

bad: by sticking with the rotary, it almost sent mazda broke and ford ended up bailing them out

good: after that mazda were able to continue on their development work and come up with what we see in the RX-8 and now theyre working on a hydrogen IC rotary

crisis
11-09-2003, 05:47 PM
Originally posted by megotmea7
only through miss information and the general concensus that rotarys are "unreliable" and put out no torque. the FD put out plenty of torque and with a redline of 8krpm you can gear for more torque and your argument becomes pointless, rotarys are performance engines, they make great power from a small size and small displacement, when you say youd rather have 1.8 liter 4 than a rotary what about a 2 liter 20b 3 rotor? you want torque? lmao and thats closer to the displacement than the 1.3 liter 13b-rew, compare ANY 4 cylinder to the 20b in terms of reliability modability, performance(and keep in mind it came in a luxury car...) and if your worry'd about gas mileage then i wouldnt even be worry'd about a performance car. gas consumtion is the killer of the rotary in the 80's if it wernt for the ga crunch you be seeing rotarys in everything. after the gas crunch GM and mercades droped their projects, mazda was the only one to stick with it and if ppl can get over the misconseptions and see the truth i wouldnt doubt other manufacturers would start toying with it again. on paper the design is almost perfect(more perfect than any piston engine, only thru use of better materials and developent it will come to blossom(the piston engine has been around forever, if the rotary had as much development as piston engines we wouldnt be talking about it in the current context.

PS i read thru this whole thread and theres so much ignorance im not going to bother with responding to, even if i did most these ppl arnt even around anyway...

Having to rev an engine to 8000 rpm to make up for a lack of low down torque really exposes the deficiencies in the design . And no doubt explains the lack of fuel economy. If you can live with poor fuel economy buy a V8 and have torque , power and ordinary fuel economy. Similarly if you have to gear the car to compensate for the lack of torque it is a compromise. Rotaries are a novelty and without the innovative RX8 car itself would probably be listed under historic engines by now.

megotmea7
11-09-2003, 08:49 PM
again the FD RX-7 had plenty of "down low" torque its sequential turbo setup made up for any "design flaws" with the rotary, with a downpipe and non sequential conversion it has more downlow torque than befor without the advantages of the sequential setup...

crisis
11-09-2003, 11:37 PM
Originally posted by megotmea7
again the FD RX-7 had plenty of "down low" torque its sequential turbo setup made up for any "design flaws" with the rotary, with a downpipe and non sequential conversion it has more downlow torque than befor without the advantages of the sequential setup...
So youre saying to perform it needs two turbo chargers?

fpv_gtho
11-09-2003, 11:49 PM
honestly crisis, uve got to admit that for a 1.3L engine its got alot of torque. compared to the power its shit but i havent seen any NA 1.3L engines get 211nm of torque other than the renesis

megotmea7
11-09-2003, 11:57 PM
So youre saying to perform it needs two turbo chargers?
im saying after the turbos were made non sequential(they work as one) it still had more down low torque than most give it credit for, the N/A rotarys are peaky admitidly but turbo rotarys are torquey as the next turbo I4 or I6 you can find... with less than half the displacment :D

megotmea7
11-10-2003, 12:07 AM
Having to rev an engine to 8000 rpm to make up for a lack of low down torque really exposes the deficiencies in the design
explain to me the "deficiencies in the design" of a rotary being revv happy? the simple fact is rotarys are more comfortable at higher rpm that piston engines the very few internal components rotate at 1/3rd the the rate of revoulutions per minute compared to piston engines rotating assemblys rotating just as fast as the rpm with the added stress of reciprocating motion(pistons constantly changing directions startng and stoping wasting more energy on inertia than the rotary). if you measered the actual rotor speed at the 8000rpm redline it is only rotating at ~2666rpm with zero reciprocating motion. the only thing in the whole motor that is rotating at 8000rpm is the eccentric shaft, a solid rod of forged steel with 2 offset lobs. no cams nothing... flaw in design?

crisis
11-11-2003, 08:28 PM
Originally posted by fpv_gtho
honestly crisis, uve got to admit that for a 1.3L engine its got alot of torque. compared to the power its shit but i havent seen any NA 1.3L engines get 211nm of torque other than the renesis
But it doesnt use the same fuel as a 1.3 litre. Its pointless to compare it that way. You can make a 1.3litre engine produce twice that with a turbo and then we may be talking the same fuel economy. Not to mention the cost of a car with a rotary to start with. Not that I would like a 1.3lt turbo powered car. The case for rotaries has been decided by the fact that only one manufacturer, which is one of Japans least successful, perseveres with it.

megotmea7
11-12-2003, 02:43 AM
The case for rotaries has been decided by the fact that only one manufacturer, which is one of Japans least successful, perseveres with it.
i bring it back to the fact that chevy, benz, and others were going to use the rotary but droped it due to a "chance event" like the gas crunch, blaming the design of the rotary for others manufacturer lack of the ability to take a chance isnt a valid point, they dont take a chance because of the reliability aura that surounds the rotary be it true or not, to the average un informed person that even knows what a wankel engine is, it is a unreliable gas hog and for the most part that isnt true and what is true is based on mazdas price cutting at teh factory and the owners lack of knowledge of the engine and its control systems before they blew it up

crisis
11-13-2003, 05:44 PM
Originally posted by megotmea7
i bring it back to the fact that chevy, benz, and others were going to use the rotary but droped it due to a "chance event" like the gas crunch, blaming the design of the rotary for others manufacturer lack of the ability to take a chance isnt a valid point, they dont take a chance because of the reliability aura that surounds the rotary be it true or not, to the average un informed person that even knows what a wankel engine is, it is a unreliable gas hog and for the most part that isnt true and what is true is based on mazdas price cutting at teh factory and the owners lack of knowledge of the engine and its control systems before they blew it up
Why take a chance on something that at best performs adequately. It revs hard , which used to be an advantage until Honda and now others have made conventional motors that can rev as well. Other than that Benz and Chev made a decision based on what they percieved to be the benefits of persuing a new type of motor that even if it worked , as we see it has with Mazda, offers no real advantage over a cheaper conventional motor.

Cappy
11-14-2003, 11:36 AM
One of the reasons why the rotary has trouble competing with the piston engine is because it has not been improved and optimized by dozens of top-name automotive manufacturers for over 100 years. At this time only 1 manufacturer makes 1 car with the rotary. Think about it...

One of the problems of past rotaries is delicate apex seals which are intolerant of even a single serious detonation. In order to combat this, rich fuel/air ratios are used, but this does not promote fuel efficiency. Modifiers that increased power to the RX-7 without considering fuel flow and ignition timing had problems. I don't know if the Renesis' apex seals are more durable.

The ability of rotaries to rev high (if you call 8-9k rpm high) is not a disadvantage. As long as the engine is able to safely operate at this, there is no reason not to take advantage of it.

crisis
11-17-2003, 12:15 AM
Originally posted by Cappy
At this time only 1 manufacturer makes 1 car with the rotary. Think about it...

I think that sums it up.

Cappy
11-17-2003, 09:03 PM
That's not fair. So most companies don't think it's worth the financial risk. That doesn't mean it's a bad design. It just means it's not a profitable one...or that most companies don't have the balls or know-how.

crisis
11-17-2003, 11:26 PM
Originally posted by Cappy
That's not fair. So most companies don't think it's worth the financial risk. That doesn't mean it's a bad design. It just means it's not a profitable one...or that most companies don't have the balls or know-how.



your point would hold a little if at least one other company was interested. No other company, means a resounding vote of no confidence. And they've all had long enough to guage MAzda's success.

Falcon500
11-23-2003, 06:48 AM
well there once was a company called NSU who built a car called the Ro80 this car was only months off mazdas first rotarie engined car and they would of beat them if the suppliers of the engines had of gotten them some earlier. The car was good it had great handeling a semi automatic transmission which worked with an electric switch and then operated a vacume system (this actually worked to mask the twin rotors poor torque) but the engine was what killed the car its rotor tip seals worse out after 15,000 miles and NSU had to replace them under warrenty with some cars going through 9 engines! It killed the company in the long run.
There are other similar storis like that but i find that one the most interesting.

crisis
11-24-2003, 06:03 PM
Originally posted by Falcon500
well there once was a company called NSU who built a car called the Ro80 this car was only months off mazdas first rotarie engined car and they would of beat them if the suppliers of the engines had of gotten them some earlier. The car was good it had great handeling a semi automatic transmission which worked with an electric switch and then operated a vacume system (this actually worked to mask the twin rotors poor torque) but the engine was what killed the car its rotor tip seals worse out after 15,000 miles and NSU had to replace them under warrenty with some cars going through 9 engines! It killed the company in the long run.
There are other similar storis like that but i find that one the most interesting.
Well if thats not and indictment what is. I know NSU were around for a while and made motorcycles. Killed by a stinking rotary.

megotmea7
11-24-2003, 09:26 PM
they would of beat them if the suppliers of the engines had of gotten them some earlier


Killed by a stinking rotary.

sounds to me like they were killed by a lack of... lmao ;)

-datsun 1600-
12-13-2003, 03:38 AM
Some of Australias fastest imports are rotarys ,joe signorellis s6 rx7 7.584-400m and rx3 pacman 7.66-400m you cant tell me these are slow times but it could be just of the light weight and strong chasis

automotion
12-20-2003, 05:10 AM
sounds to me like they were killed by a lack of... lmao ;)
It seems many of you in this thread are interested in 'rotaries', but there is not enough information available about them. Two participents are 'on the money', many are just 'grabbing for straws'. It seems, you all want to find out more? Keep it factual; cut out the crappy language.
I read every post & reply.
Some history first: NSU was not killed by the Wankel, but by changing times; they did not dissappaer - Audi bought the company. Many companies bought licenses from NSU for one million dollars at the time, just to be allowed to research and experiment with this potentially promising type of power plant.
Another point: Ford is alowing, even assisting, Mazda to come up with this new generation of Wankel rotary, because they see the potential.
I have worked with Wankels in R&D ...

crisis
12-21-2003, 05:16 PM
Some history first: NSU was not killed by the Wankel, but by changing times; they did not dissappaer - Audi bought the company. Many companies bought licenses from NSU for one million dollars at the time, just to be allowed to research and experiment with this potentially promising type of power plant.

Where are they all then?

Bear87G
01-15-2004, 06:20 PM
Everyone seems to be having a good old debate and some great points have been put up. I have not read through all of the posts but only skimmed threw so bear with me on my response.

The wankel rotary has many great feature first and formost in my mind (being an F1 fan) is the fact that there are no recipricating masses. Meanign in english that there are no weight parts that have to stop and change direction which cause huge problems in high revs and reliability. In a pistons engine the piston goes up stops comes down stop and goes up again and so on....but in a rotary engine the rotor only moves in one direction so the ability for high end revs on the motor is almost limitless. Through my eyes I would put the rotary in Formula 1 if I could it would probably rev higher than any of the piston engines that participate now as well.

In the end the torque of the engine is there and the engine can be tuned to have torque in different places. Torque values in a rotary are not the same as in a piston engine with just a slight lesser amount for the rotary which is not terrible. Reliability on the engine is rock solid considering in my garage I have a Wankel with major problems yet after 500,000 miles.

The engines have yet to be perfected as they are only being advanced upon my one company and are still some what of a gasoline hog. Emmisions and fuel mileage have been on the rise and continue to get better with the new Mazda rotary the Renesis. When you only have one company using this wonderful motor and still surviving and making it popular how fast do you expect technology advances to be. There are over 100 car manufacturerer's around the world working on advancing the piston engine while one is suposed to do what over 100 can do for a different engine. This speculation shows that to say the rotary will never become a super motor as the piston motor has become is ignorance. The rotary is a wonderful design and I myself as an engineer am working on an new model for the rotary that will not appear for some time due to the complication and preciseness of the experiment.

All I will tell you in the rotor may in a few years have between 5-10 firing processes per rotor revolution. You should be able to figure out from there what I am trying to do and if you acheive this goal before myself congrats.
bear

Evil Ewok
01-15-2004, 06:53 PM
The wankel is an amazing design, and an amazing engine. The only things (yes plural) I find wrong with it is that there should have been more though on how to cool one of these thermal plants. The other is, of course, oil pressure. Why the 12a's dump oil....I do not know. But other than those, the engine is amazing. Sure fire power, and torque, rev happy, amazing response, great for drift, speed, anything that you want to do. That's why these engines are always winning races. Or were at least, until the upset at mazda. Le Mans, 24 hours of bathurst, JGTC, 12 hours of sebring (believe) and so many other races that have been one by the commitment of a good idea that runs strong.

Matra et Alpine
01-15-2004, 07:10 PM
..
Through my eyes I would put the rotary in Formula 1 if I could it would probably rev higher than any of the piston engines that participate now as well.
Efficient combustion of petrol-based engines is increased the more compressed whilst still a vapour the fule/air combo can be. That is achieved in F1 and GP bikes by HIGH compression. Wankel's can NEVER have high compression because we lack the basic materials to have seals at the tips.
Remember that a 4-stroke will ahve multiple seals(rings) per piston. Each with a different purpose and make-up. VERY difficult in Wankel.

Reliability on the engine is rock solid considering in my garage I have a Wankel with major problems yet after 500,000 miles.
What loads has that engine been under ?
That is NOT on for curent Wankel's run at high loads.
Sports cars run engines at high loads.
2-strokers can go on for ever as well if they're run at low loads !!


This speculation shows that to say the rotary will never become a super motor as the piston motor has become is ignorance.

Sorry but to sugest that beacuse Mazda retain it is because only they know it is superior is a rather odd conclusion. It's more marketing than performance !
Decades ago the MOST ADVANCED engine users played with rotary and walked away. Bike engineers have been producing the highest power/weight ratios and endurance for decades.


The rotary is a wonderful design and I myself as an engineer am working on an new model for the rotary that will not appear for some time due to the complication and preciseness of the experiment.
The Wqnkel concept is an ELEGANT design.
Unfortunately it has drawbacks.
I'm sure the advocates of the Watts steam engine held out against the IC engine 100 years ago :-)



All I will tell you in the rotor may in a few years have between 5-10 firing processes per rotor revolution. You should be able to figure out from there what I am trying to do and if you acheive this goal before myself congrats.
bear
As an engineer and experienced tuner, I'm intrigued at how you will create between 5-10 chambers on a single rotor with reasonable efficiency. What compression ratio for fule/air will their be. How much energy per combusion and what losses with trying to seal 5-10 chambers !
Attempts in the past have proposed chamging chamber shape AS the rotor turns. These failed at early investigation at the realisation that it all added weight and compromised combustion chamber integrity.

Check out the NAGATO cycle engine which was patented in 2001 which handled the 'rotation' in a novel manner - by 'fixing' the seals and having the rotor 'wobble' ( best way I can describe it ) to get the combusiont cycle to run.

Want to go off-line for a more private chat to see if the idea is sound and if lessons from earlier attempts can be passed on. ( Not sure where friends are now, but could maybe find them ) ????

PS: I always felt the equivalency calculation FIA and ACU used was unfair and they should have done it on the physical size of the engine EXTERIOR. There was an advantage 20 years ago when we didnt' have the experience in the exotic materials in todays best engines.

Matra et Alpine
01-15-2004, 07:24 PM
Just checked and Dave Renegar has had his patent granted in 2002 for the flexible vanes.
It's about the best way of achieving what you're trying to do, but I still don't know that we have the 'smart' materials needed to make the flexi-vane work.

But hey, HE got the patent - congrats !!

fpv_gtho
01-15-2004, 09:25 PM
That's why these engines are always winning races. Or were at least, until the upset at mazda. Le Mans, 24 hours of bathurst, JGTC, 12 hours of sebring (believe) and so many other races that have been one by the commitment of a good idea that runs strong.


that was the bathurst 12 hour race which it won 3 years straight

NAZCA C2
01-15-2004, 10:15 PM
The rotary engine is a great design. It only has 2 moving parts. I wonder if it could be used in a motorcycle since it is a compact design.

crisis
01-15-2004, 11:29 PM
The rotary engine is a great design. It only has 2 moving parts. I wonder if it could be used in a motorcycle since it is a compact design.
It was but I cant remember which one. Quite some time ago.

crisis
01-15-2004, 11:35 PM
The engines have yet to be perfected as they are only being advanced upon my one company and are still some what of a gasoline hog. Emmisions and fuel mileage have been on the rise and continue to get better with the new Mazda rotary the Renesis. When you only have one company using this wonderful motor and still surviving and making it popular how fast do you expect technology advances to be. There are over 100 car manufacturerer's around the world working on advancing the piston engine while one is suposed to do what over 100 can do for a different engine. This speculation shows that to say the rotary will never become a super motor as the piston motor has become is ignorance.
The fact that no one else has adopted it tells me that they dont think it is worth spending money on. If it were truly outstanding and could offer performance, economy or anything else that a conventional motor can , Im sure Mazda would not be the only ones persuing it. Mazda are not the most conventional manufacturer and realise they have a captive market for any rotary they produce. There are a lot of rotary lovers out there. But MAzda only produce one car with it. If Mazda truley belived in the design was the answer to everything they would surely use it in more of, if not all their cars.

Matra et Alpine
01-16-2004, 04:25 AM
The rotary engine is a great design. It only has 2 moving parts. I wonder if it could be used in a motorcycle since it is a compact design.
Yep, well remembered, the great NORTON.

There's a good history covering 1969-1987 of the engine and bike development at the Norton Owneres Club. Select 'History' -> 'Rotary' at http://www.noc.co.uk/

The race bikes history 87-94 and specs are at http://www.jpsnorton.com/racebikes.asp and the thing to notice is how SMALL the engine is. It was a 588cc - engine equivalency rules dictated that. But it was TINY compared to the 4-strokers and even smaller then the 2s.


I remember it from the 92 Isle of Man TT where a young Steve Hislop took it to 2nd in the Senior and 1st in the TT. Great sound - here's a video clip of the day
http://www.jpsnorton.com/videoclips/hisloptt.ram
( dont' blame the camera man, on the IoM you sit within inches of the bikes passing at anything from 110 to 170 mph. STILL the best motor spectacle in the world - roll on June :) )

Matra et Alpine
01-16-2004, 04:32 AM
The rotary engine is a great design. It only has 2 moving parts. I wonder if it could be used in a motorcycle since it is a compact design.
Unfortuntely, it MUST have water cooling to ensure plug temparatures so unfortunately it loses on p/w as most bikes don't need water cooling until they're 1000+ cc.
Bike manufacturers have the moving mass of a 4-stroker down so low they can rev them to 20000+ with VERY high efficiency, so it's not got a large advantage. And you want to see the size of the Honda V5. The complete engine AND gearbox fits into a plastic shopping bag :) and the reports say that big-H could get 250BHP out of it if they want to.

dupscadi
01-18-2004, 01:18 PM
IN the early 70's, Johnson made a snowmoblie with a Wankel. It's engine was a small displacement. I don't know power ratings or displacment, but it was a compact design and could be fitted to a small bike if one wanted to waste that kind of time. I'll see if I can find out how big the engine is, it is in the back yard anyway.

Matra et Alpine
01-18-2004, 02:45 PM
Well to redress the balance in case anyone thinks I hate Wankels :)

Here's an interesting list of Le Mans entries I found at http://www.millville.org/workshops_F/kess_mech/tools/1tools/lemans.html

RCE Entries at Le Mans
Yr Qu Fin

70 41 -- Chevron B16, Mazda 10A 2rotor 200 bhp
73 14 -- Sigma MC73, Mazda 12A 2rotor 260 bhp 9K rpm, Ikusawa, Fushida & Dal Bo
74 27 un Sigma MC74, Mazda 12A, 1st Japan chqd flag. Terada, Okamoto, Harukuni
74 -- -- Mazda S124A coupe, 12A 2rotor 260 bhp
75 50 -- Mazda S124A coupe, 12A 2rotor 260 bhp, Buchet & Rondeau
79 -- -- Mazda RX-7 252i, 13B 2rotor 285 bhp, 0.59 sec out of qualification
80 54 21 Mazda RX-7, 12A 2rotor, Soto, Hutchins & Honneger
81 -- -- Mazda RX-7, 12A 2rotor. Vermeersch, Stiff & Honneger
81 49 -- Mazda RX-7 253, 13B 2rotor. Terada, Fushida & Percy
81 51 -- Mazda RX-7 253, 13B 2rotor. Walkinshaw, Lovett & Izukawa
82 50 14 Mazda RX-7 254, 13B 2rotor. Terada, Yorino & Moffat
82 53 -- Mazda RX-7 254, 13B 2rotor. Walkinshaw, Lovett & Nicholson
83 43 12 Mazda 717C, 13B, Terada, Katayama & Yorino. Won C Jr
83 42 18 Mazda 717C, 13B 2 rotor, Allam, Weaver & Soper
83 -- -- Harrier, 13B 2 rotor. Baker, Honneger & Palmer.
84 42 15 Mazda 727C, 13B 2rotor, 320 bhp. Kennedy, Martin & Martin
84 32 20 Mazda 727C, 13B 2rotor, 320 bhp. Terada, Yorino & Dieudonne
84 39 12 Lola T616, 13B 2rotor, Busby, Knoop & Hayje
84 38 10 Lola T616, 13B 2rotor, Katayama, Morton & O'Steen. Won C2
85 40 24 Mazda 737C, 13B 2rotor, Katayam, Terada & Yorino
85 43 19 Mazda 737C, 13B 2rotor, Kennedy, Martin & Martin
86 25 -- Mazda 757, 13G 3rotor, 3532cc (654x3x1.8), Katayama, Terada & Yorino
86 29 -- Mazda 757, 13G 3rotor, Kennedy, Galvin & Dieudonne.
87 28 7 Mazda 757, 13G, Kennedy, Dieudonne & Galvin. (best Japan yet) Won GTP
87 27 -- Mazda 757, 13G, Katayam, Terada, Yorino, 18 hours
88 37 15 Mazda 757, 13G 3rotor, Terada, Dieudonne & Kennedy. Won GTP
88 29 17 Mazda 767, 13J 4rotor, 550-600 bhp, Katayama, Duez & Leslie
88 28 19 Mazda 767, 13J 4rotor, Yorino, Regout & Hoy
89 28 7 Mazda 767B, 13J 4rotor, Kennedy, Dieudonne & Hodgetts. Won GTP
89 16 9 Mazda 767B, 13J 4rotor, Yorino, Regout & Forbes-Robinson
89 34 12 Mazda 767, 13J 4rotor, Terada, Duez, Weidler
90 23 -- Mazda 787, R26B 4rotor, Johansson, Kennedy & Dieudonne
90 22 -- Mazda 787, R26B 4rotor, Gachot, Herbert & Weidler
90 34 20 Mazda 767B, 13J 4rotor, Katayama, Terada & Yorino. Won GTP
91 12 6 Mazda 787B, R26B 4rotor, Kennedy, Johansson & Sandro-Sala.
91 17 1 Mazda 787B, R26B 4rotor, Gachot, Herbert & Weidler, OVERALL WINNER
91 24 8 Mazda 787, R26B 4rotor, Terada, Dieudonne & Yorino.
96 24 25 Kudzu MazdaSpeed, Terada, Downing, Freon.
97 17 17 MazdaSpeed 97, Terada, Downing, Freon.

Mazda is the most reliable finisher: 67 % of the times it has entered (31 cars)), the highest reliability of any maker, except Honda, who entered only one year (3 cars) and all 3 finished. The next closest was D.B. (?) (France) at 55 %.


Of course, it's still the case that 'equivalency' makes a mockery of comparisons on power AND longevity. The 1991 car was a 2.6l 4-rotor. Hard to compette with that amount of 'bang' in a V8/12.
But that's life - go ask a GSX-R racer in World Superbikes :)

davidpnut
02-05-2004, 10:47 AM
Yup.

Interesting idea that; not practical, but interesting nonetheless.
Think about the Honda Civic Hyrid or the Toyota Prius. They have assists, which are very helpful. Plus, you can get energy back when you break. Putting an electrical assist on the Wankel would be awesome.

Matra et Alpine
02-05-2004, 11:04 AM
Putting an electrical assist on the Wankel would be awesome.
Even better, on a Stirling engine.
The electrics could cover the long start-up time :)
Stirling cycles are THE msot efficient engine made.
( Another scottish invention before it's time !! )

fpv_gtho
02-05-2004, 10:43 PM
whats the sterling engine?

Egg Nog
02-06-2004, 12:08 AM
whats the sterling engine?

The Sterling External Combustion Engine, as described by Road and Track to the best of my memory:
Advantages: Low noise, low emissions, high efficiency
Disadvantages: The existance of other engines

"The modern Stirling Engine is a clean and efficient engine. This is because the heat fueling the device is supplied from outside the engine. Thus creation of pollutants can be eliminated. The external combustion aspect enables a Stirling Engine to operate equally well on multiple types of fuel, such as natural gas, propane, gasoline, diesel, bio-fuels, or even heat from the sun. "

(From SESUSA)
http://www.sesusa.org/

Another good site here:
http://www.bekkoame.ne.jp/~khirata/

Two really good animations:
http://www.keveney.com/Vstirling.html
http://www.keveney.com/Stirling.html

The always-excellent HowStuffWorks article:
http://www.howstuffworks.com/stirling-engine.htm

Japan's "Sterling Techno Rally"
http://www.nef.or.jp/english/info/lupo8e.htm

A good Sterling Engine History:
http://www.cse.iitk.ac.in/~amit/courses/371/abhishe/main.html

And finally, and image: This is pretty interesting (at least for fellow physics fans): From a small MIT-designed Sterling Engine, this is the graph of Work -vs- ΔTemperature...

fpv_gtho
02-06-2004, 12:11 AM
thanks for that Egg Nog

Matra et Alpine
02-06-2004, 09:50 AM
whats the sterling engine?
STIRLING.
Invented by a Reverend Stilrling a Scottish Church of Scotland Minister :)
HONEST !!!
He was fed up with parishioners being kiled and maimed when early steam engine boilers would blow up. So decided to invent a better engine.
It's an amazing machine to watch - especially modern low-temparature-difference engines :)
It's best where you don't mind it taking time for an engine to get up to speed and can take advantage of it's constant working speed.
A web site will find you lots of info.
There's a perticular US company who product Stirling engines and make small ones. I've seen the 'coffee cup powered' one and it's amazing to watch if.
One of the big US companies built a car with an engine as a 'test', don't know what happened to it or other car research.

Doza
02-10-2004, 07:01 PM
The Sterling External Combustion Engine, as described by Road and Track to the best of my memory:
Advantages: Low noise, low emissions, high efficiency
Disadvantages: The existance of other engines


What kind of power does it make?

Egg Nog
02-10-2004, 08:13 PM
What kind of power does it make?

Well, Sterling Engines can very in size quite highly, so I can't really give an exact figure... I made one at home from some wood, some elastics, a tin can, and a couple of other things. Probably not quite in Bugatti Veyron territory yet :)

Anyway, I think one of the disadvantages is it's relatively low power output for the size of the engine. Many issues have been dealt with, but I don't really think this is very possible considering the relative simplicity and efficiency of the engine, and how it functions.

Matra et Alpine
02-10-2004, 08:26 PM
I think one of the disadvantages is it's relatively low power output for the size of the engine.
Stirling folks, STIRLING - I can hear him spining from here :)

Anyway, the Stirling engine power is related to the temparature differential between the two ends of the engine. THIS is the limiting factor. Quite powerful multi-cylinder engines have been built. But we're not talking more than a handful of HP !! Some research subs have used Stirling engines - infinite 'sink' of cold sea for the engine :) guess you can keep the hot end in a nuc reactor !! Don't know how practical they really are.

Egg Nog
02-10-2004, 09:37 PM
Stirling folks, STIRLING - I can hear him spining from here :)

Oh man, my bad :eek: Sorry, I must've missed that before.

My apologies go out (or should I say under) to Rev. Stirling. :)

crash8168
02-15-2004, 09:49 PM
Anyone has something to tell about the Wankel Engine???

something in favour, or against...

I think it is a good engine...
Most of the time seal damage was due to incorrect spark plugs installed in the engine.

rxheaven
06-16-2004, 04:59 AM
The one thing i have not seen yet in this thread is a post from someone that actually drives an rx7 or the like. I can kill all questions about reliability. I drive an 82 rx7. It has never been rebuilt and still has the original motor (12A). this motor has done over 210000km in that time the only reason it needs any work done at all is that an oil o-ring has hardened when the engine was not run for a few years. The main reasons for problems with this type of motor is one of 2 things. Most of the time it is due to stupid young drivers that rev the car way to much my engine redlines at 7000rpm it will keep reving until there is no more fuel or something goes bang. The other reason is alot of people do port jobs to the motor. These do produce more power but like any modification put more strain on the motor. Poor port jobs or just ports that are to big eg. J ports (if you realy want to know look it up) put strain on the apex seals. Now as for pistons I am nowhere near as well informed on there problems, but most of my mates run heigh performance motors and they spend a hell of a lot of time fixing there worked cars. As a side note the year mazda won lemans they actualy striped the motor in public to prove the reliability. That race is all about not breaking the car and well the powers that be have done what every other person has done with this type of motor, they baned it. This is the main reason there has been no R&D into the motor. I sell cars for a living there is a saying "race it on sunday sell it on monday" if you can't race it it is hard to sell it, if it is hard to sell there is no money for R&D.

I may have covered a few points previously mentioned but i feel better for the effort. :D

Mustang
06-16-2004, 08:21 AM
well since i dont know alot about the wankel engine accept that it doesnt have pistons i thaught i might as well just post this pic from the motorshow :)

megotmea7
06-16-2004, 02:00 PM
The one thing i have not seen yet in this thread is a post from someone that actually drives an rx7 or the like. I can kill all questions about reliability. I drive an 82 rx7. It has never been rebuilt and still has the original motor (12A). this motor has done over 210000km in that time the only reason it needs any work done at all is that an oil o-ring has hardened when the engine was not run for a few years. The main reasons for problems with this type of motor is one of 2 things. Most of the time it is due to stupid young drivers that rev the car way to much my engine redlines at 7000rpm it will keep reving until there is no more fuel or something goes bang. The other reason is alot of people do port jobs to the motor. These do produce more power but like any modification put more strain on the motor. Poor port jobs or just ports that are to big eg. J ports (if you realy want to know look it up) put strain on the apex seals.
i have a '94 FD touring, the motor decided to go last year at about 110k miles(water seal ruptured leaking coolant into the housing and bubbling off into the radiator, most likely do to my impatience and unwillingness to do a full 10 minute warm up when i was late for work :rolleyes:. this was with a T04X, full exhaust, PFC, and 414hp @12psi) i have yet to take the old motor apart to se but i suspect a warped housing also but hey it still ran when i took it out took some pushing to get it started and alot of white smoke but it ran :), currently putting a streetported 13b-REW in with ceramic seals and hoping to push upwards of 500hp, i dont know about your SA but most common killers of FC's and FD's is the inpropper warm up and cool down that these motors require before and after hard driving, when modifying you have to increase fuel flow as well as airflow(probly the #1 killer of FD's), unreliability/insuficientness of the cooling system and imporper design of the downpipe/precat which both cause overheatig which will kill your rotary real quick, and imporoperly secured vacuum lines which pop off and cause the entire sequential switchover to cease to exist till you dig thru the hunders of lines to find the one that came off(pain in the ass...) the thing about the SA's and the 12a is it burned fuel like none other(not a flaw but designed in to lubricate the seals, its designed into every modern rotary to date) had horrible gas mileage, and some just gave up not 50k miles after running. :(

babel17
06-16-2004, 06:11 PM
The one thing i have not seen yet in this thread is a post from someone that actually drives an rx7 or the like. :D

I owned an 82 RX7 with the infamous 12a motor. I bought it after it already had over 200,000 miles on it. The previous owner used it mainly for a 50 mile daily commute. I blew the apex seals after driving it about 6000 miles.

I guess it is how you drive.

But, I now own an RX8, and I just aint happy until I hear the rev limiter ding. Wonder how many miles I'll get. :)

bullitproof7
11-21-2005, 05:49 AM
Rotary engines were used in Mercedes Benz pre 70s i think they were racing them,while the mazda 10a was pretty lame the 12a and 13bs with or without turbos offered a great platform to build on that didnt require all the internals a v8 had ,the pistons broke if you even thought about performance modifactions,a rotor can be modified easier and was not as expensive to extract some big hp or 1/4 mile times.Two things in its favour are its revving capabilitys and its light weight compared to some V8s.Now with 20bs things have progressed again and gotten quicker.PACPERFORMANCE ran a 6.96 400m with there 20b 2 weeks ago at the jamboree.THAT WAS :eek: FULLY SIK
My s2 rx7 with a PAC built s413bt ran a best of 12.7 on street tyres

Matra et Alpine
11-21-2005, 06:26 AM
Mercedes only ever put the rotary in the first prototype C111s.
That was their test-bed for the technology.
I wasn't aware that any had ever been raced seriously.
The latter C111s that stormed the record books were DIESEL powered :D

h00t_h00t
11-21-2005, 04:48 PM
Rotary engines were used in Mercedes Benz pre 70s i think they were racing them,while the mazda 10a was pretty lame the 12a and 13bs with or without turbos offered a great platform to build on that didnt require all the internals a v8 had ,the pistons broke if you even thought about performance modifactions,a rotor can be modified easier and was not as expensive to extract some big hp or 1/4 mile times.Two things in its favour are its revving capabilitys and its light weight compared to some V8s.Now with 20bs things have progressed again and gotten quicker.PACPERFORMANCE ran a 6.96 400m with there 20b 2 weeks ago at the jamboree.THAT WAS :eek: FULLY SIK
My s2 rx7 with a PAC built s413bt ran a best of 12.7 on street tyres
The 20b has the advantage of and extra rotor. Hence all the power.