1.3L

Among my collection of conversation pieces sitting on the back of my bench here at work (pistons, hard drives, etc.) is a rotor from an early Wankle engine. It measures 60mm in width so I believe (not sure) that it's from the 1.0L 10A engine. The rotor appears to made of cast iron and is surprisingly heavy. Are the rotors in the new 13B made of iron, or are they made of something a bit lighter such as an aluminum alloy, or what?

1.3L

Red Devil

I want to say that they are still iron, but I'm not completely sure about that.

rx8wannahave

IRON...really, gosh is it the high temp, high RPM...or why would they have to be iron?

Also, does anyone know the weight of the Renesis? I just heard someone say that its weight is very close to the LS2...if so, the Rotary engine is loseing some of it's reason of exsistance...and I'm begining to understand why alot of car companies don't make it.

Teach me please...

PoorCollegeKid

The Renesis weighs in at 303lbs while the LS2 weighs in at 445lbs, so it is a good deal heavier than the Renesis. For camparison's sake, a Honda F20C (S2000's 2.0L) weighs in at 326 lbs, and the VQ35DE out of the 350Z/Altima/F35/... weighs about 420lbs, so you can see that the Renesis is lighter in terms of absolute weight than all of these engines. The Renesis is also a good deal smaller than these piston engines, which is another of its appealing features. However, its gas mileage is noticeably worse than these more powerful engines (going by reports from people on this forum and the forums for the other cars mentioned) and it also doesn't quite have power:weight ratios of these engines, although it is very close to the VQ's and the F20C's.

Tayninh

I got this on searching the web:

DIGITAL TECHNOLOGY

An example of Mazda's advanced use of digital technology can be found in the machining of the engine's rotors. Three dimensional design data is received from the engine development team and employed to create 3-D data for a metal die for casting. Based on this 3-D data, computer simulations are used to analyze and check the precision, quality and efficiency in the rotor casting and machining. Also, with regard to cutting and other machining processes, 3-D simulations are used to optimize the design of cutting tools and jigs throughout the entire manufacturing process.

They reduced rotor weight by 11%. I think its iron still.

G8rboy

They are still cast iron... the rotors in the FC's 13B weighed 9.6lbs, the rotors in the FD weighed 9.0lbs, and in the Renesis they weigh 8.6lbs. I think you're right about your rotor being a 10a- I think the 13B's are 80mm wide. Not sure about the 12A...

G8rboy

It's still lighter than the LS2, and considerably smaller packaging. That's a huge benefit in building a balanced car, being able to position motor behind the front axle, as is the RX-8. Other companies don't make it because they haven't had the years and years of RD that Mazda has... a few have dabbled though.

StewC625

I thought they were made of Rotanium ...

G8rboy

I have it on good authority that the next RX7's rotors will be made out of unobtainium :D

rx8wannahave

Yes, 145 pounds is significant…wow...I forgot that 220 pounds or so is not typical weight for an engine (my NX2000’s 2L weighed about that)

Dang, the VQ is a fat V6 (or is the LS2 very light)…or is it me? Yeah, I heard the Renesis was small and that it helps with it’s balance N stuff.

Thanks for the information!

Now, I wonder why they cant make it out of something else other the OLD TECH IRON?

jsh1120

How about carbon fiber? I'm sure someone on e-bay will be selling carbon fiber decals for the rotor before long. :D

EandGWZ

My personal preference with the Renesis and the Rx-8 happens to be more about engine performance (overall). If it didn't have a rotary engine or back seats I would have never bought it.


Curb Weight (lbs.) 2835 for the s2000


Curb weight lb. (minimum w\ popular options) 3,053 for the RX-8


I suspect the size of the engine/type of engine plays a role in the cars styling/balancing/performance/ and yes, ability of dropping rear side in the back and not losing significant performance figures.

dkelly3854

HAHAHAHAHAHA :D

Rotarian_SC

The LS series has had excellent power to weight ratios, some of the best among engines.

wakeech

...iron isn't old tech, it's "low" cost (at scrap rates, iron's way more expensive than aluminum) and high strength. the reason that they can't go to aluminum is that i just don't think they're strong enough for a turbo , and maybe not even an all motor application.

the next step in manufacturing these pieces for mazda, i believe, would be to design a process where you could a high rate of production with a forging element (reducing mass, increasing strength, all that good stuff). casting the rotors with less material is just not good enough for the next generation.

SantozRx8

i thought mazda had a patent on the wankle engine or somethin like that so thats why other companies dont make a rotary..... does anyone know if that may be true?

wakeech

damned rotors.

i suppose now, thinking about it again, that the rotor of the future will be comprised of more than one piece (two, possibly three) for optimum strength and low mass. dang, tha'd be one helluva piece.

(basically, considering the design of the internals of a rotor, it's rather impossible to forge one knowing now the kind of forces required for forging)

rx8wannahave

Thanks everyone for their Rotary wisdom.

Has the LS ever won an award cause I agree, I think its one of the best engines in the world.


I wonder what's next for the Rotary...what are the things that are holding it back, how can they get better fuel economy from it, more torque...etc etc...

I'm new, actually not official yet, but it's a very interesting engine to say the least. I wonder...

Rotarian_SC

Lack of R&D and a proper aluminum bonding procedure to make a 3 rotor weigh 400lbs with accesories. I think a 4 rotor with smaller displacement for each rotor would be better, more balanced.

Red Devil

Also, for the Renesis, the housings are made of AL, but I believe the end plates are still cast iron. Switching those to AL could reduce weight maybe as much as another 35lbs. Anyone can confirm this?