animations :
http://www.rotaryengineillustrated.com/animations.html

 

I worked for the Mazda Dealer in Mediocre Falls Montana back in 1970 or so ( 'DJ's Mazda'-Oh my God what a thief!!! He belongs in the 'Criminal's Hall of Fame'!!! When he died, I'll be they buried him in a 'borrowed' casket in land he stole! What a guy!!!) when Mazda first started selling cars in the USA. I drove the first rotory Mazda, an R-100 off the rail car there, and drove it to the dealership. Yep-fast, quick, and fuel thirsty compared to other cars in it's class-about 22 mpg. They also made bigger 'family' rotory cars as time went on and even had a pick-up truck, then darn near bought the farm because of internal sealing problems and warranty claims. Not to mention, a bit hard to overhaul due to the 'non-circular' bore, and special plating. You just have to buy another engine, and the 'simplicity' mentioned is for the 'off-road' versions. On-road is a nightmare on main street what with leading and trailing spark plugs, points, dual distributors, MILES of vacumn hoses, God's curse to mankind 'Hitachi Carburettors' ("Good for 20,000 miles or just buy a new one-again!") Believe me, there's a really good reason you don't see alot of old ones around...and supposedly only one guy ever figured out how to turbo/supercharge them dependably, and he ran it in a Datsun 510 sedan because of it's independant rear suspension on the race tracks. It was also widely advised (Un-officially) to put some two-stroke oil in your gas tank... Not exactly EPA approved advice it think...

 

I love the rotory engine. Theres just something cool about a kazillion rpms.

 

It was a small wagon, but what a sleeper of a car. It was very fast and could accelerate like nobody's business, but the cops never thought of it as a speed demon type car. I went through at least 2 or 3 radar traps passing the car that the cops pulled over. The things that wore out back then were the rotor seals, which wore quickly (new engine required) and the exhaust system (replaced for $900 bucks in 1980) which was engineered for the much higher exhaust gas temperatures. Gas mileage was about equal to my wife's mazda 4 banger coupe.

In 1978, Mazda had a number of overproduced American market 1976 models which they sold if the individual would pay shipping. Total cost including shipping for a Mazda coupe and my rx-3 wagon was $4,700.00. Their standard new car warranty was honored at delivery.

 

I had an RX-7 and I loved it. It ran really smooth and was quite fast. I got it when I was a Bachelor, so I did not worry about gas mileage. I do know that they are not economical, however.
For the power they put out the engine is really very small in size. I used to think of it as a little sewing machine.
Reading Sonavabich's post he mentioned some of the problems the early rotarys had, but those have been fixed. The apex seals on the rotors, which are comparable to the rings on a piston can go 200,000 miles easy.
I did all the work on mine, but I would not want to break open the engine case and do a complete overhaul because I did not know of anyone with any real experience with the rotarys.
There was maybe still is a company called MazdaSpeed that made quite a few parts for the rotary.
One guy wrote about putting 2 cycle oil in the gas tank periodically. I never did, but I do know that on my series (1984) there was a small line to the carb that introduced tiny amounts of oil into the engine to provide a little extra lubrication to the apex seals.
Another poster touched on the fact that the rotarys have pretty good horsepower, but suck on torque. This is true and is why they perform best a high rpm.
I have been considering buying another '84 RX7 to restore, but it is very hard to find one that is straight. The only body pieces that can be romoved are the front fenders and hood, so a hard shot to the rear or doors puts everthing out of wack and is hard to put back as good as new again.

 

Course after the seals go you could always upgrade the engine to a 302 Ford, like this:

http://www.bacomatic.org/~dw/trx/trx-0.htm

 

There's a lot of research being done on these engines for this application <http://www.moller.com/skycar>

 

Alot of people like to throw 350's in them, too. Silly people...

 

Thats very sacraligous....

 

How's that? Ford and Mazda are in partnership together anyway.

 

Anyone remember the wankle motocycle?

 

Yeah I know that, but having a rotary in a Mazda is the one thing that makes it unique.

IMHO, if you are taking the rotary out of a Mazda (and I know this sounds crap) but it is kind of taking away a bit of the cars soul.
It is taking away what makes an RX-7 an RX-7, what makes it that little bit different than the ever so bland coupe croud.

I know someone previously posted a thread "why do all these people shove 350's in Fords?" and this is similar, while Ford owns a controlling share in Mazda, if you want a coupe with a 302 in it, get a Mustang, if you want a coupe with a rotary in it, get an RX.

If you have ever driven an RX-7, having a rotary engine is what makes the car special, the smooth, yet ballistic power delivery, the ever so wierd idle, the RX-7 is an animal of a different breed to any other coupe, and its why I like it so much.
It is like Mazda doesn't care about what the world thinks about conventions, or about fuel consumption for that matter - and damn it, it looks so good too.

Anyhow I will get off my soapbox now.

BTW I have a mate with a 1981 2wd Mazda B-Series that he has fitted a triple rotor in it, and I asked him why - he doesn't drag with it - and he replied "well its different ain't it"
I can't argue with that.

 

I agree with everything you've said. However if I'm sitting on an RX-__ with a blown motor or one with worn out seals and it isn't rebuildable, I would seriously consider a V-8. I have driven an RX-7 and being able to rev it to 7000 rpm freely was way cool. I just wish they were rebuildable or that the expertise to rebuild them was available.

 

Yeah good point.

I have a good rotary mechanic, which helps (rotaries are pretty popular in Australia compared to the rest of the world), but I can understand if getting technical support is difficult, it would be easier to shoehorn a 302 into the engine bay, at least its better than a 350...