How Rotary Engines Work

[Noriaki]

Just a sidenote:
I was told once:

The RX7's 1.3L is decieving.

With a piston you have to use the same area displacement for all 4 strokes.
A rotor is in 3 of the 4 cycles as once. So you have to multiply the displacement by 8/3 to get the effect displacement to compare to a cylinder based engine.

I don't know if it's true, or if it with a different multiplier, as I said I was just told it once, I can't verify it or anything.

But I just thought I'd throw it out there.

 

[TripleJ]

I'm a big fan of rotary engines. It's genius how it works. I could watch the apex seal keeping in continuous contact with the housing for ages. Round and round and round and round...

The Orbital Engine Corporation is located just near me in Perth. I've been there once and had a look at their stuff. Very interesting.

 

[apoppin]

I have 2 Rotary (13B) Mazda Cosmos. The 1.3 L engine produces up to 300 hp without turbocharging.

There are 4 chamber Rotarys used for racing that produce up to 600 hp (not bad for 2.6 L displacement). Engine rebuilding is EASY and is a one man operation.

I was restoring those cars before my accident but will probably egay them pretty soon.

 

[RossGr]

Isn't that continous contact of the tip seal the biggest problem with the rotary engine? On a piston engine the rings come to a complete stop twice (top and bottom) each cycle thus do not see near the friction that the continuous velocity rotary seal does. What have they done to solve this proplem?

 

[Sluggo]

In the early rotary engines, seals were the biggest problem, as time passed and better materials were developed, rotary engines really came into their time.

 

[edblor]

Thanks again for a great link B,



Edblor

 

[apoppin]

The seals are greatly improved.

Rotarys routinely last 200,000 miles between rebuilds (which are easier/cheaper than conventional engines).

Rotarys race in a class that are double their displacement - i.e.: 1.3 L Rotary vs. 2.6 L conventional.

 

[geno]

<< The 1.3 L engine produces up to 300 hp without turbocharging. >>


How come they came turbocharged from the factory with more than 40HP less than that?

 

[apoppin]

<< How come they came turbocharged from the factory with more than 40HP less than that? >>



First of all it is a mild turbocharge boost. Secondly, many of the newer rotarys use a slightly smaller engine displacement than 1.3L - the 13A. And the factory ones are laden with smog controls.

Mine aren't.

 

[NFS4]

<<

<< The 1.3 L engine produces up to 300 hp without turbocharging. >>


How come they came turbocharged from the factory with more than 40HP less than that? >>


The RX7 still lives on (with slightly revised bodywork) in Japan and I think it's pushing out 270 - 280HP there.

 

[geno]

I thought the Twin Turbo was pushing 10lbs of boost? I know someone with a 3rd gen, and he's running 10lbs and he said that was stock...

 

[Adul]

I thought they where going to produce a 3 rotor version of the RX-8. It would have put out 320 - 340 HP. Guess not then

 

[geno]

<< The RX7 still lives on (with slightly revised bodywork) in Japan and I think it's pushing out 270 - 280HP there. >>


Yeah, I heard the Supra was still around in Japan even after it was axed here. Is mazda going to keep producing it until the RX8 comes around?

 

[apoppin]

There is a 4-rotor version of the Rotary in Japan - up to 600hp (used for racing).

I believe the RX-7 got axed here when they couldn't meet smog requirements (and some other import technicalities).

The Rotary engines will take a very high turbo boost (as in racing). Unfortunately the engine life is diminished dramatically. In racing were talking regularly 10,000 RPM. 11-12,000 is ultimate redline for a 13B before it disassembles.

 

[geno]

Yeah, I know someone around here pushing close to 30lbs, but he's blown his engine about 3 times (he's on his 4th now). Runs high 10s and it's dead stock on the outside except for rims, how nice is that?

 

[randomlinh]

i don't really like the rx8 stylin, but good to see them come back to a rotary engine... which reminds me.. i saw a newer style rx7 when i went to best buy one day.... just parked there nice and shiny silver

 

[NFS4]

Here's the current RX7:

http://www.rx-7.mazda.co.jp/

 

[geno]

You can clearly see where the RX-8 got some of it's styling ques from in some of the pics on that site...

 

[whizbang]

I have a Mazda Millenia and, if you're interested in something a bit different than the normal engine, the Millenia has a Miller Cycle engine. Not quite as radical as the Wankel, but still interesting.