Why is it that Mazda is the only car company using rotary engines in their product? I have no experience with them, but I’ve heard that rotaries are much simpler, smoother (obviously), and lighter.
(I’m posting this in IMHO instead of GQ because I expect I’ll be getting opinions on rotary-vs-recipricating engines.)
A couple of other automakers were working with rotary engines a while ago, but when the fuel crisis hit in '73, they one by one dropped their rotary programs. While the rotary is a simpler, smoother, and lighter engine, it is also dirtier, and more fuel thirsty. It’s kind of dissapointing that more automakers don’t use them.
Especially considering that Mazda is getting 250 HP out of a 1.3 liter, naturally aspirated motor 
Because one of the heads of Mazda was good friends with Wankel, who invented the rotory engine type that they use. Seriously. I saw an interview with him, and he practically worshipped the guy. Other car companies have expressed interest in using rotory engine, but haven’t done it. The AMC Pacer was originally going to be using a rotory engine, bought from GM, but when GM cancelled the engine (because they couldn’t meet emissions standards cheaply enough for GM), AMC had to do some massive redesigning and retooling of the Pacer. (Other Pacer trivia: It was designed on the back of an air sickness bag on an airplane. Notice that the headlights look like the windows on a plane.)
Engineers tend to be a conservative bunch and work with the things they know. (This isn’t necessarily a bad thing, either.) So, since few engineers have experience with Wankels and other types of rotory engines, no one considers putting them into cars. Plus, NIH tends to play a major role in automotive thinking as well.
Just wanted to pop in and say that the rotary is going to be back in the US this year with the Mazda RX-8
I had a 1991 RX-7 until last July. I loved the car, but it did go through a ton of gas around town. Not too bad on the highway. Probably a function of the way I drove it too though.
Back in 1973 or '74, Chevrolet contemplated using a rotary engine in the Corvette. AMC designed the Pacer to be outfitted with a rotary engine, as well.
Just stumbled across this in some of my bathroom reading that deals with the Wankel
So, juding by that, it looks like they’re a bitch to make as well.
:smack:
Sorry, Tuckerfan!
No problem, didn’t know that it was the 'Vette that GM was looking to put the rotory in! Wonder if the real reason that GM killed their rotory was because they found out that AMC was planning on putting it in a Pacer? (Personally, I’d take a Pacer over new Vette, any day, but I’m weird like that.)
I used to know someone that had a Mazda, and when the engine was in fine shape, it truly was in fine shape. The problem is the seals/vanes at the rotor tips. On his car, at least, the vanes didn’t last long, necessitating an engine tear-down every three or four years.
I, for one, am very happy that the RX-8 is going to be available, and that there will be another rotary powered car for sale in the US.As far as engines go, the rotary is quite fascinating.
I’ve always thought that if as much time and money was invested in the rotary as is the piston engine, it would be a better engine than the piston engines in place now.
The rotary engine is way cool for many reasons, but it has a couple of inherent problems
First off the apex seals wear. This can be controlled somewhat by oil injection, but it is still an issue.
Secondly it is a thirsty bastard. Fuel mileage is poor. It makes lots of power, but it uses lots of gas to do it. Not the most saleable idea since the gas lines of '73.
Thirdly and this is a real bitch, the exhaust is very dirty. Unburned HC, CO and NOX. They can be cleaned up, but it is expensive to do so. In these days of ever tightening smog rules, that pretty much limits the rotary to a low production sports car role.
I have read up on the RX-8 and I recall seeing they had fixed many problems with the incomplete combustion on the rotary engine by moving the ports from the edge to the face of the static part. Incomplete combustion addresses both dirty exhaust and gas mileage.
Ahem… I’m trading my miata up for an RX8 as soon as they ship to Canada… They’ve managed to fix a lot of the problems associated with rotary engines in the past. Re-design of the intake systems have made it (apparently for the first time) possible to pass emissions standards in California. I believe the mpg figure is 30-35 in the city - not bad.
I’ll let y’all know how it drives. 
-n
Don’t worry soon I’ll have a better design out there if the patent goes through.
Here is a little info on the Renesis…
http://www.carmemories.com/cgi-bin/viewexperience.cgi?experience_id=624
Also, according to Mazda’s website, fuel mileage on the rx-8 is 18/24 city/highway.
HaHaHaHaHa (HoHoHo) HaHaHaHa:p 30-35 in the city, that’s funny. Modro stole my thunder. You’d be lucky to see 20. You’d get better gas mileage with a V8. That’s why the engine never caught on in the aviation world. You have to haul around all that extra gas so the lighter engine/fewer parts scenario doesn’t help.
I have always been fascinated with the rotary engine but it has a HUGE shortfall. It is not as tuneable as a 4 stroke piston. There are no valves so you are stuck with tweaking intake/exaust portals. They also have the torque of a Metro. Not very fun to drive around town.
You have so many more parts in a conventional motor but that makes it more tunable. You can tune for any power band with a 4 stroke motor. I’m rebuilding a turbocharged 4 cylinder and I expect somewhere between 350 and 400 hp when I’m done.
I would look at turbo charging a miata before I dropped lots of money on a rotary anything. I think there are even kits to swap in a V8. I would also look at the Passat W8 engine. That uses staggered cylinders to shorten the engine length.
Actually, I would look at a lot of different cars, including the Mazda RX8. There are just so many neat sports cars being built today.
“Wankel Rotary Engine”
giggle
I was just gonna say that the phrase “Wankel Rotary Engine” keeps Aaron in stitches. 
Robin
The website addresses the deficiencies in the original rotary engine (most notably event-timing). Mazda has introduced variable intake timing and they’ve eliminated intake/exhaust overlap. This should make it a new animal worthy of a look-see.
Since this is a 4 door I would definitely compare it against VW Passat with the W8 engine.