Thread: Rotory Engine

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OK i have no idea what a rotory engine looks like or how it works or anything, all i know is that the tuner guys will not shut up about it saying that it is so much better than a V8 and that you can get so much more power out of it than any other engine and get better gas miliege.


so is this true, are rotory engines so freakin great, if so why, how so they work what do they look like.

the rotary engine is not better than a v8...

People in the pocket rocket crowd like the rotary engine because they can be turned in excess of 12,000 rpm when built right. They make good power but they do not last much more than 70,000 miles if u treat them right.

ok thank you

My experience has been that they seem to have NO bottom end torque either.

rotaries are great in cars that weigh hardly anything.... but they're not fuel efficient that a lot of people use as a debate, and yes they put out a lot of power.... for their size... a whole 1.1L- 1.3L.... but also if you overheat them once, then they're fried.... and they're incredibly expensive to build....

Rotaries are definitely a power making engine, but better than the V8? I doubt it. Rotaries are also thirsty little devils too. Much more than size equivalent 4's and 6's. Probably more like a small v-8. They are easy to rebuild since there are only 3 primary wear points (each on the tip of each rotor crown), however, probably not many mechanics outside of Mazda knows how and if you can't do it yourself, it will likely be expensive.

I believe the Mazda Rotary is a single rotor engine and they do make very good power. However a number of years back (about 25 to 30, I think) Mercedes Benz experimented with rotaries and produce three models with rotary engines. The most notable was the C-111, a beautiful wedged shape vehicle with a three rotor rotary engine. The engine pushed the car to speeds in excess of 220 mph. Much to the disappointment of sports car enthusiasts world wide, MB did not put the C-111 into production, so regardless of how much money you had, you could not buy one.

i personally would have loved to see them built (I couldn't afford one for sure), but MB elected to abandon the project and continues to this day to produce normal piston engines for all of their cars. Therefore suggesting that the Rotary was not better than the standard inline or V piston engines. In fact, if MB really believed the Rotary to be superior, then I am sure they would be running them in their hign end cars as well as their race cars. Others, of course, may draw a different opinion. But for now, that's mine.

A dohc inline 4 can develop over 700 hp, far more than any small rotary. Nearly all tuner guys build 4's for racing because of the lower acquistion cost and the inexpensive power potential.


__________________
A little history never hurt anyone, unless of course it's revisionist history.

Bob

Originally posted by mopar34
Rotaries are definitely a power making engine, but better than the V8? I doubt it. Rotaries are also thirsty little devils too. Much more than size equivalent 4's and 6's. Probably more like a small v-8. They are easy to rebuild since there are only 3 primary wear points (each on the tip of each rotor crown), however, probably not many mechanics outside of Mazda knows how and if you can't do it yourself, it will likely be expensive.

I believe the Mazda Rotary is a single rotor engine and they do make very good power. However a number of years back (about 25 to 30, I think) Mercedes Benz experimented with rotaries and produce three models with rotary engines. The most notable was the C-111, a beautiful wedged shape vehicle with a three rotor rotary engine. The engine pushed the car to speeds in excess of 220 mph. Much to the disappointment of sports car enthusiasts world wide, MB did not put the C-111 into production, so regardless of how much money you had, you could not buy one.

i personally would have loved to see them built (I couldn't afford one for sure), but MB elected to abandon the project and continues to this day to produce normal piston engines for all of their cars. Therefore suggesting that the Rotary was not better than the standard inline or V piston engines. In fact, if MB really believed the Rotary to be superior, then I am sure they would be running them in their hign end cars as well as their race cars. Others, of course, may draw a different opinion. But for now, that's mine.

A dohc inline 4 can develop over 700 hp, far more than any small rotary. Nearly all tuner guys build 4's for racing because of the lower acquistion cost and the inexpensive power potential.


__________________
A little history never hurt anyone, unless of course it's revisionist history.

Bob

mazda rotaries actually have 2 rotors, and the rebuild cost depends if you need apex seals or not, if you do depending if you want the 3 piece seals or the 1 piece seals, you'll pay anywhere between $300-900 just for those, new rotors, you have to buy in matching sets which will run you another $400-1000.... then theres those that get bold and port their motors, which if done right can put out 900hp n/a but they blow up really quick.... the rotory really isn't superior to the v8.... the more prospective looking style motors starting to be produced are the miller cycles and the 5 -stroke motor that crower is releasing in a few months, but both of those are just a different variation of a piston motor

Mazda won the 24 Hours of LeMans in 1991 with a 4 rotor, 2.6L engine that produced over 700 HP at 9000 RPM's. This was a normally asperated engine.

Rotory's make a lot of power, and at one time GM had looked at the possibility of using one in the Corvette and the Vega was also supposed to (and was designed to) get a rotory. The two big issues with a rotory are poor fuel mileage and keeping emissions in check. With corporated fuel economy standards and strict emissions requirements, the engine is not practicle in large volume cars (and the RX-8 can hardly be called high volume).

As for rotory's being better than a V-8, it certainly was in France in 1991. But unless the displacement is increased, it won't make the type of power Americans are used to. As also mentioned, these engines are more expensive to build. In many ways though, these are not that bad to rebuild. When a rebuild basically means replacing the seals, this isn't that bad. But overheating one will blow the seals. Oiling issues in turbo applications have been problems in the past as well (see the last RX-7).

GM built a 4-rotor rotary engine powered Corvette in the early 70's. It made something along the lines of 450 hp. It was only a concept, though.

I had forgotten about the Corvette. Memory has struggles at time, but I seem to remember seeing the prototype and believe it was to be a mid engine car. Nice body lines, unfortunately never got to production. Too bad.

Rotaries do kick ass, but as noted only in the hp per cid dept. every thing that has been said so far is true. Let me add that the burn alot of oil too. The damn thing are almost like 2 strokes!
Norton built a rotary motorcylce racer in the late 80's. Succssful at the Isle of Mann TT race. Also they are also used in Milliary Drone aircraft (target practice).

If rotories were better than V8's, than there would not be a kit ( very popular kit ) to put a SBC in a Mazda RX7, there good engines but there not fuel efficent. The real name is cool tho, Wankel, kinda sounds funny.

the rotors rotate around an ecentric shaft with plugs on the intake and exhaust side if the engines

Originally posted by Matt167
If rotories were better than V8's, than there would not be a kit ( very popular kit ) to put a SBC in a Mazda RX7, there good engines but there not fuel efficent. The real name is cool tho, Wankel, kinda sounds funny.

even more popular swap is on the FCs, you can direct swap a 5.0L mustang motor in because ford and mazda used the same chassis/ motor mounts on those year cars