rotary engine

[Jonno]

Geez, what a coincidence, I just finished a assignment on rotary engines!

Rotary Engines

The rotary engine was designed by Dr. Felix Wankel and work on the engine started in 1924 and the prototype was finally built in 1954. It is still used in airplanes and some of Mazda’s cars, such as the RX-3s to the RX-7s and also in a few others, like the Cosmo, ECT.

The way the rotary engine works is that there is a rotor (a triangle shape with rounded surfaces) that fits into a housing so it has three compartments where the surfaces of the rotor are. The rotary engine has 4 main stages, intake, compression, combustion and exhaust. The intake means the intake of the fuel where the fuel is let into the one of the compartments in the housing and is taken to compression. The compression stage is where the fuel is compressed as the rotor forces it against the wall of the housing into the combustion compartment. The spark plugs are timed to spark when the rotor passes them. There is two sparkplugs because of there was one, the flame would spread too slowly. and 3 would be too many. This means there is two sparkplugs per rotor. The exhaust stage is when the gases that are left of the fuel are pushed through the exhaust port because the room of the chamber is decreased as it passes the rotor housing.

This picture is cut out from a screen shot taken at http://www.howstuffworks.com/rotary-engine.htm. It shows all the stages that the rotor takes.
As the fuel is ignited, it builds up pressure causing the rotor to move. The Crankshaft is passed through the middle of the rotors (there is more than one rotor in different housings) which powers the car or Aircraft.

As the rotor moves it uses Kinetic energy and friction as it turns.

The rotary engine is a more reliable than a piston engine because it isn’t constantly changing direction; the rotor moves in a circular motion and is a smoother process.

Bibliography

http://www.howstuffworks.com/rotary-engine.htm
http://www.monito.com/wankel/
http://www.rotaryengineillustrated.com/




Like it? :hehe:

[higgimonster]

you gotta love 'HowSuffWorks.com' This whole thead could have been answered with a link to there. However. I am interested in that 787b. I rember the car kicking-ass in GT3 but I didn't know rotaries were banned after they won. what year was that?

[Dustin_S]

I can't wait to get one of them new Mazda RX-8s.

*drool*

[Jimster]

Originally posted by Dustin_S
I can't wait to get one of them new Mazda RX-8s.

*drool*

me neither..........Very sexy

[EvilWankel]

I tried to post earlier, but it was too busy when I sent the post, so that pissed me off So about the 787b, the year it ran was in 1991. As far as I understand, it placed 1,3,and 4th place that year. When they tore the engine apart to inspect how it reacted to the race, it was said that it could have gone for another 24 hours. The engine was a whopping 2600cc, 4 rotor rotary engine, with an extra plug per rotor, making 700 HP. http://www.2751engineering.com/787.html there you all go, enjoy By the way, rotary rules all

[replicant_008]

The main issues with Rotaries were three-fold:

Reliability - Initially at least, there were significant issues with wear on the apex seals in particular. Also there have been issues with bearings too but this more to do with some users taking them to high rotation speeds that the engine maker ever intended.

Fuel Consumption - This was the major downfall of the engine arriving around 1972 when fuel consumption became such a major issue which is why only NSU and Mazda took up the licences for production.

Emissions - Control of the combustion process was relatively not particularly understood with this design and if ever an engine required carefully managed fuel-air ratios this was one - a spin off of better consumption (by improving the efficiency by improvements in port design and spark plug placement) was improvements in fuel consumption.

NSU actually made the first production wankel-cycle engines and paid the price for being the trail-blazer as the company ended being swallowed by the VW-Audi Group after experiencing financial problems.

As for the 787 Racer it remains the sole Japanese Entry to win Le Mans. But even the most ardent supporter would acknowledge that the limit on fuel consumption for all cars imposed for that race meant that the fastest cars in the race were never able to be unleashed at full speed.

[Jimster]

Originally posted by replicant_008


Fuel Consumption - This was the major downfall of the engine arriving around 1972 when fuel consumption became such a major issue which is why only NSU and Mazda took up the licences for production.

placement) was improvements in fuel consumption.

Indeed, AMC wanted a Wankel Rotary engine for thier Pacer, that went to shit once the fuel crisis came, and a straight six it was

[EvilWankel]

Originally posted by replicant_008
The main issues with Rotaries were three-fold:

Reliability - Initially at least, there were significant issues with wear on the apex seals in particular. Also there have been issues with bearings too but this more to do with some users taking them to high rotation speeds that the engine maker ever intended.

Fuel Consumption - This was the major downfall of the engine arriving around 1972 when fuel consumption became such a major issue which is why only NSU and Mazda took up the licences for production.

Emissions - Control of the combustion process was relatively not particularly understood with this design and if ever an engine required carefully managed fuel-air ratios this was one - a spin off of better consumption (by improving the efficiency by improvements in port design and spark plug placement) was improvements in fuel consumption.

NSU actually made the first production wankel-cycle engines and paid the price for being the trail-blazer as the company ended being swallowed by the VW-Audi Group after experiencing financial problems.

As for the 787 Racer it remains the sole Japanese Entry to win Le Mans. But even the most ardent supporter would acknowledge that the limit on fuel consumption for all cars imposed for that race meant that the fastest cars in the race were never able to be unleashed at full speed.

Reliability- The only problem in reliability came with the turbo models. The naturally aspirates models can go for over 200,000 miles. The turbo models had problems with getting the reliability. That was the downfall of the third generation RX-7. One of the worst problems for the rotary is overheating. But that is a big problem with other cars as well.

Fuel Comsumption- As I have stated before, my car would make a good 19 MPG with my real heavy foot. The turbo gets about 16 MPG.

Emissions- Yeah, these cars do make alot more dirty stuff than the pistons, but they make an air pump to shoot out more air into the atmosphere with the dirty stuff, which helps emissions I suppose.

[replicant_008]

Evil my comments were related to the early rotaries - particularly the early NSU and Mazda engines. Seals were a major problem then but with technology and computing power - along with major improvements in port design a lot of the problems were overcome... however NSU did last long enough to bear the fruit of the work done to bring the wankel-cycle engine to a production reality...

[Jimster]

Originally posted by replicant_008
Evil my comments were related to the early rotaries - particularly the early NSU and Mazda engines. Seals were a major problem then but with technology and computing power - along with major improvements in port design a lot of the problems were overcome... however NSU did last long enough to bear the fruit of the work done to bring the wankel-cycle engine to a production reality...

True, if you remember the Citroen GS birotor, that tried to start a rotary craze, but never really succeded, because the fuel crisis was near and the heavy consumption of the Wankel wasn't going to cut it, it failed so dismally, Citroen paid the owners to give them back so they could be scrapped, the seals are a big problem in teh 12A and early 13B engines since they are rubber, which means they aren't very durable, bt I'm pretty sure that it was the Series 6 (Don't take my word, could have been earlier) that they were replaced with soft stainless steel seals


I've never like the two-rotor engines, whenever they turn up to the track days the Alfas, Ferraris, Maseratis, Lotus', Jensens etc. Give them a good hiding, can't beat a good 20B though (Of course I wouldn't know because I invested in a crapped-out 20B :o )

[EvilWankel]

Originally posted by Jimmy_11_cars



True, if you remember the Citroen GS birotor, that tried to start a rotary craze, but never really succeded, because the fuel crisis was near and the heavy consumption of the Wankel wasn't going to cut it, it failed so dismally, Citroen paid the owners to give them back so they could be scrapped, the seals are a big problem in teh 12A and early 13B engines since they are rubber, which means they aren't very durable, bt I'm pretty sure that it was the Series 6 (Don't take my word, could have been earlier) that they were replaced with soft stainless steel seals


I've never like the two-rotor engines, whenever they turn up to the track days the Alfas, Ferraris, Maseratis, Lotus', Jensens etc. Give them a good hiding, can't beat a good 20B though (Of course I wouldn't know because I invested in a crapped-out 20B :o )

I am going to assume you are in Europe somewhere, because of the cars you named. I guess I dont know alot about the Citroen car, but here in America when the first gen RX-7 came out in 79 alot of people bought it because of the gas mileage. I know my RX-7 makes 19 to 20. how much do your cars make? And with the seals, I think it was mainly the turbo seals that would crap out. I have heard of rotary engines kickin at 69k miles because of overheating, and one of the cars I bought had 173k miles, and it had a blown seal.

And with all of those cars you named (Alfas, Ferraris, Maseratis, Lotus', Jensens etc.), what do you expect? It's a tiny motor. These cars are that you name are great cars on a rich man's budget. RX-7's are in the 20,000 dollar range. And I know of a guy that does autocross in his 13b single turbo that wipes the floor with M5's, lotus's, etc. It's just gotta be set up right. I cant imagine what a 13b twin turbo would do at race events.

Last, you bought a 20b? What was the problem with it when you got it?