What is the difference between a conventional engine and a rotary engine??

Question

i am looking at buying a mazda RX-8. would it be a smart buy?

Answer 1

I'll give you the short answer skinny, and then you can do some basic research. The rotary engine and piston engine are completely different concepts. I have nothing against the rotary engine - also known as the "Wankel" engine after its inventor - but there are some things that you should consider:

1 - Higher repair costs.

2 - Potentially higher maintenance costs.

3 - Possibly increased insurance premiums.

Check into these things. The RX-8 is a hot car, and the Wankel is very very powerful due to its design, but due to inherent design limitations it will never be - not in my lifetime anyway - a highly competitive engine for fuel efficiency and maintenance costs.

So should you buy it? I don't see any reason why not, just be aware of what you are getting into. The engine is very very powerful and aggressive, so watch your foot. The RX-8 resale value would be good as well. To educate yourself fully, go to Wikipedia and search on "rotary engine". They will show you an animation of how the Wankel works and its development history and limitations.  

Answer 2

Conventional engines use pistons that go up and down.  Rotary engines use a triangular wedge that rotates.  The RX-8 is a very nice car.

Answer 3

In our experience rotary Wankel engines vibrate and pollute like mad. They have internal wiper rings which don't have the life expectancy of a piston engine.

Go to: Wikipedia Encyclopedia to see what a rotary Wankel motor looks like as compared to a four cycle multi-piston engine.

Draw your own conclusion! Hint, Just one look will turn you off!!

Answer 4

My son just purchased a 1985 RX7 with 187,000 miles on it.   Still runs like a top once he put new plugs and wires on it.   These are much simpler than a conventional engine and early models had seal problems but Mazda fixed that in the 80's.    They were the first to offer a 100,000 mile engine warranty.  Mandated by the government for sure due to early problems but these engines are rugged and dependable.   Easily go over 200,000 miles if you take good regular service and care of them.

Great car but limited space for two back passengers.  Good for small kids or a doggie.    But a fun sporty car...  Sticks to the road like nothing for this price.

Enjoy.

RoyG

KC

Answer 5

HowStuffWorks has a good chapter on Rotary engines, as far as the technical aspects and benefits versus drawbacks;

http://www.howstuffworks.com/rotary-engi...

Contrary to another poster's assertion, they run quite smooth. Better power to weight ratio. Poor gas mileage though, and hard to find people who are good at working on them because of their rarity.

Here's the chapter on engines in general for some more background on the differences between the two;

http://www.howstuffworks.com/engine.htm

A great little car when they're working right, but not very good for someone on a budget, or who isn't mechanically inclined, and willing to learn how to work on them themselves.