robrecht

Following upon the exciting Frazer-Nash/Giugiaro Namir concept at last year's Geneva auto show, Audi will this year have a series hybrid with a single-rotor Wankel range extender:

http://www.egmcartech.com/2010/03/01...own-in-geneva/

Obviously, the size and weight advantage of the rotary is important here, but some also say that a rotary running constantly at its sweet spot can also be more fuel efficient than a piston engine of comparable power running at its sweet spot.

I wish Mazda had developed this use of the rotary rather than hydrogen combustion.

rotarygod

Give it time. Hydrogen will be a dying fad after they finally reach the conclusion that it really isn't all that efficient or cheap. All internal combustion engines are destined to be range extenders someday as the end of the internal combustion engine powering the wheels is within many of our lifetimes.

DrKillJoY

Ever the wet blanket RG.

brillo

I have always said the rotary may finally find its place as a "generator" for electric cars. Nice to see someone trying to make that happen. Hopefully Mazda may do the same.

8 Maniac

iTrader: (1)

The real future of cars is external combustion engines.

I'd definitely like to see how something like this would work as a mass produced vehicle.

robrecht

I was thinking about this some more, wondering where Audi sourced their Wankel, when I remembered that Audi was part of a merger formed by Volkswagen when they bought NSU, for whom Felix Wankel worked when he was developing the rotary. So, conceivably, Audi developed their own Wankel from the rights to the engine they acquired with NSU. It will be interesting to compare Audi's new single-rotor Wankel with the 498 cc 50 hp single-rotor Wankel found in the 1964 NSU Spider.

The Namir mentioned in my first post used a Wankel developed from the successor of Felix's own company.

Wonder how many, if any, of Mazda's patents were used in either of these engines?

hornbm

iTrader: (1)

I think you fail to understand what internal combustion means in the first place.

External combustion would be... toasty...

b'Eight'

The predecessor to internal combustion was steam power where water was heated externally (boiled) and injected into the combustion chamber.

8 Maniac

iTrader: (1)

I think you fail to understand what humor is like in the first place.

External combustion engines would be fun and awesome. I'd love to see how one might work though.

I'm not going to count steam.

robrecht

Here's a little Fiat that was made into a series hybrid with a small go-kart/aviation single rotary from Aixro:

http://www.aixro.de/wp/allgemein/range-extender/

Someone at this link wondered if one of these Aixro engines might be what's used by Audi:
http://www.autoblog.com/2010/03/01/g...th-wankel-rot/

Feras

iTrader: (1)

http://uncyclopedia.wikia.com/wiki/E...bustion_engine

robrecht

Here's some more details. The single-rotor Wankel engine is only 254 cc; the gas tank only takes 3.17 gallons, and the battery weighs 331 lbs, with the total weight of the car being 2,624 pounds:

http://wot.motortrend.com/6615301/gr...#ixzz0h1qpywPc

http://www.autoblog.com/2010/03/01/a...-geneva-2010/2

http://www.themotorreport.com.au/499...ngine-featured

rotarygod

I couldn't get through all of the Autoblog comments. There are always people on there that argue against the rotary who are extremely closed minded and misinformed about it. Unfortunately most of this blame lies squarely on Mazda for taking something inherently simple and reliable and making it the exact opposite through shortcuts in other areas. The other issue with the rotary is that by far most rotary owners are complete morons who can't take care of them. This is sad but true as many rotary owners today either bought an RX-8 because of it's looks or are kids with RX-7s because they are cheap. The true rotary fans know how to treat them but are the minority of rotary owners anymore. Someone takes their older turbo rotary and blows it up and suddenly it's the engine's fault. I have NEVER blown up a rotary engine! I can't say I haven't been rough on them either.

One rotary I saw and now own was a first gen RX-7 that was owned by a lady for 25 years. Original owner. She drove it normally as a daily driver and was religious about oil changes and maintenance. The car was in great shape and the engine had good wear internally. However everything was all gunked up with carbon. Seals were sticking so compression was low. She didn't know this. She thought the engine had gone out. I bought the car for $300 and did some magic on it and brought it back to life. When I pulled the engine out, it took forever to get it clean. Wear was so good that I reused everything right down to the apex seals. The engine had 103,000 miles on it at this point. The auxiliary ports were stuck shut from carbon so I cleaned them up and got them working. I did some port work and put it back together. That engine runs like brand new. Had she have revved it up every once in a while it would be perfect. I've never seen a nicer engine with that many miles on it. Not even any chrome flaking on the rotor housings which was impressive.

She is one type of rotary owner. Takes care of it but not being a fanatic doesn't know that you should rev them up every once in a while to keep them clean. Others ignore oil changes and run low which hurts the engine, even though they don't drive them hard. These are the types of people that kill naturally aspirated rotaries and help give them a bad name. Others have forced induction and get greedy or don't tune properly. Then you get the problems from Mazda. The 3rd gen RX-7 was a beautiful disaster in monumental proportions. Substandard cooling. Terrible turbo design. Poor coolant seals in the engine. A MAP based system which is intolerant to changes without tuning. I am a fan of these systems though. Then we have the RX-8. They should have gotten it right but messed up with the oil metering. No oil injectors spraying the center of the apex seals where they need it the most. Not until the 09's came out did they get it right. Sadly this may have been too late.

The rotary in concept is simple and reliable. Holding a generator at 5000 rpm and running it lean should keep carbon to a minimum.

lesper4

iTrader: (3)

I guess I never really read about the A1 that much, didnt realize there was a rotary in it, that is pretty cool.

rotarygod

There's not a rotary in the A1. It's only their A1 hybrid concept car.

robrecht

Looks like AVL of Graz, Austria engineered the system for Audi. Here's a very similar prototype designed to be fitted into a Mini:

http://www.a3ps.at/site/images/stori...2009_10_16.pdf

rotarygod

In regards to the external combustion engine, one actually does show alot of promise. It just doesn't look like what we think of when it comes to steam engines.

http://www.cyclonepower.com/index.html

robrecht

I spoke with an employee of AVL. Their Wankel engine is a prototype designed from scratch. The design and simulation was done by AVL and the test-bed development and validation of the first prototype phase is currently in progress at their facilities. Most of the the prototype production was done by their own machine shop or by smaller machining partners in Germany and Austria. Nice to see some new Wankel development.

zoom44

hey since you're talking to them do you think you can get some more dimensions och of them? i see the 50mm width and 1/4 liter for the single rotor but maybe you can get width and eccentricity? and the 2 rotor in the pdf, is it a half liter then? and is that meant to be the shape of the bathtub as depicted? didn't we see a photograph of something like that recently?

zoom44

oh we did see a pic with a bathtub like that recently.

*backround obscured to protect the innocent.*

robrecht

What's the picture on the left? Is that what you might call a resurgence of LDR (leading deep recess) or maybe even LWR (leading wide recess)??? I'm happy to ask them more questions if and when I hear back from them next with responses to my most recent set of questions. I'm also hoping to meet someone at the NYC autoshow.

zoom44

yeah see how the pic from the AVL pdf uses the same LDR shape. that could suggest they are looking at higher compression for alcohol or diesel fuels or even natural gas.

john deere SAE paper on LDR NG engine http://www.sae.org/technical/papers/910625

zoom44

robrecht? anything new?

robrecht

No, I think they lost patience with my too many questions. Nor did Audi bring the rotary series hybrid to the NY autoshow.

zoom44

Head of Audi says the A1 etron with wankel range extender WILL NOT go into production. They believe that their stop-start systems and brake recovery will make it efficient enough. plus there seems to have been some issue of packing everything into that chassis.

http://www.autoblog.com/2010/06/23/r...t-be-produced/