Mazda stops making Wankels

[quote=“Machine_Elf, post:15, topic:744429”]

Compared to a conventional piston engine, the combustion chambers of a Wankel engine have a high surface-area-to-volume ratio. This has a couple of important consequences:

[ul][li]The flame front can’t reach all the way to the walls of the combustion chamber, leaving a thin layer of unburned mixture (see flame arrester for explanation of this phenomenon). This is true for conventional piston engines as well, but the relatively larger surface area of the Wankel combustion chamber results in higher emissions of unburned hydrocarbons. You can fight this with a bigger catalytic converter, but at some point the expense/packaging requirements get to be just too much.[/li][li]High surface area also means relatively high heat loss; a larger portion of the heat of combustion gets dumped into the engine block (and ultimately the radiator) instead of being converted to mechanical work. This means crappy efficiency/MPG. Unlike the unburned-HC problem, there’s not a lot you can do about this.[/ul] So it ends up being a double-whammy: compared to a conventional piston engine, a Wankel needs to burn more fuel to get down the highway, and it makes more emissions per unit of fuel burned.[/li][/QUOTE]

If I’m not mistaken, the Apex Seals must be lubricated by a quantity of oil administered via the carburetion delivering the fuel, much like a 2-stroke engine.

How much dirtier does the exhaust get from being oily?

Good riddance!!!

They suckered me into buying one of those POS cars – the first new car I ever bought.
What little I eventually got paid in the class-action lawsuit didn’t cover the years of trouble I went thru.

Nearly half a century later, and I would never, ever even consider buying a Mazda vehicle. Damn crooks.

Shoe.
Megaphone.
Grunties.
Wankel Rotary Engine.

Years ago I stuff a Mazda rotary engine into a 73 Toyota. It was an ugly little 4 door sedan. Won many red light drags with that thing. Broke the transmission input shaft and parked it in my father’s wrecking yard. No idea what happened to it after that.

I’ll admit to not having any direct experience with Mazda’s rotary engines, but I’d be willing to bet they haven’t been carbureted for a long time; emissions regulations are so tight these days that the fuel has to be metered very precisely, and you’re only going to do that with computer-controlled fuel injection.

In addition, motor oil contains ZDDP, which acts as a “poison” for the catalytic converter; pass enough ZDDP-laden oil out the exhaust port, and the cat is going to stop cleaning up the exhaust.

Bottom line, I am doubtful that Mazda has been producing passenger cars any time in the past couple of decades with carburetors or oil injection. Which leads me to wonder, just how they hell are they lubricating those apex seals? :confused:

They’ve been fuel injected at least since the final generation RX-8 was launched in 2003.

I had a Suzuki RE-5 with the rotary. Ugliest motorcycle ever.

Collector’s items now.

When I mean carburetion, I mean “fuel delivery system”…which includes fuel injection.

Here’s a site that confirms a special rotary engine oil is fed from the crank to the intake to lube the apex seals.

https://answers.yahoo.com/question/index?qid=20120131070952AA2PZPi

My 86 was fuel injected. May have been the first year for it.

The newer EU emissions requirements probably killed it, but Mazda really hung in there - I don’t think they’ve ever gotten positive feedback on rotary engines but they just kept making them. Kinda like Honda Powersports decades-long efforts at making a motorcycle with an automatic transmission…

4 years ago? I don’t think they can pass emissions in any reasonable form.

I was tempted to buy an RX-8 when they came out, but just couldn’t get over the lack of torque and, more importantly, the horrible fuel mileage due to the rotary engine. I always thought the RX-8 would have been a lot more successful with a relatively small turbo piston engine. It would have almost certainly delivered much better fuel mileage and more torque.

I just loved the Wankel because it was so quirky. And it did have certain engineering advantages. On the other hand, it just looks like it plain would not work on principle (every time I watch an animation of one in action, it just doesn’t look right), much less the engineering challenges of making it work in practice. Which just made it all the more “magical” in my mind.

Eons ago I recall reading a book on the history of the Wankel. It was pretty interesting IMO.

After he drove my first new car for a few years, a 1979 Fiat X1/9 (great, fun car BTW), my brother bought his first new car, a 2nd-gen RX-7. He loved it. I never figured out why, because he had apex seal problems and poor fuel economy. He loved it though, and later he replaced it with another 2d-gen. Today he’s driving an RX-8. He is stubborn, my brother.

That was the first year they all were fuel injected. The 84-5 GSL-SE were also fuel injected 13Bs, like yours, but the regular RX7s were still carbureted 12As.
I’ve owned 3 RX7s, 2 82s and an 87 Turbo II. I’m in the market for another one as I’m entering my mid life crisis years and the kids are leaving, so I don’t need a back seat anymore.