Next Generation Renesis (Rotary Engine 16X), photos from Tokyo Auto Show
 

Hey all,

I found these photos last week, and was surprised that I haven't seen any buzz about this here or on the other rx7 boards. Just wanted to share these because I'm excited that Mazda is finally doing some serious development work with the rotary engine. I remember chatting with a few people from the UC Berkeley miniature silicon RE project, and they said that a thinner but larger diameter rotor was a more efficient design than the 13B geometry.




https://img.photobucket.com/albums/v...owflywheel.jpg

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I hope Mazda puts this engine in a chassis that is compact and lightweight like they did in previous decades. The Renesis in the RX-8 would be a nice motor for something small like a Miata or RX-7, but the RX8 weighs about as much as modern sports sedans, which are well into the 300 HP range by now... I hope they don't make the same mistake twice.

-s-

yeah the only thing i like at all about the Rx-8 is the renesis engine, i personally think the cars styling is crap but the engine gives me hope for rotary power in the future and now Mazda has this new 16x, lets just hope it doesn't end up in a toy car this time around.

Very nice. Thank you for the pictures.

Yes. Very nice. I am intrigued by what looks like auxiliary ports in the end plates intake manifold side but there doesn't seems to be an auxiliary port in the side plate rotor side. Would they be using one port for both?

So what just one injector per rotor? Dont you wish they stayed that shiny...:rlaugh:

I love the extra displacement idea, but I am sad that all the 13b parts and knowledge will be useless. I fear change, but welcome the extra power. :)

I bet it will be a while till they will have lower compression turbo version (if ever)

Parts useless, yes, knowledge useless, not a chance. Sure some of the specific stuff might not apply any more, but the more general stuff should still apply, as it looks like the design is very similiar to the previous motors, so the same principles should still apply.

true true I feel bad building a 13b right now though knowing I could have the extra .3L. A 20B has 33% increase .... a 16x is just short of a 20b... O.o

I'm glad to see they finally may be moving to aluminum plates. They should have done that awhile ago. Now please just put it in a small lightweight car.

-S-

The longer stroke is a great idea the 13b has a stroke of 1.1" so at high RPM its "piston speed" is pretty damn low and well in the safe range and the all aluminum should have been done a while ago. I hope there is an rx-9 or something that is small and light that it will go into or a turbocharger :)

I'll be honest I thought this thread was about the hydrogen RE/hybrid hydrogen RE projects:
http://www.motorcities.com/contents/...011111669.html
http://www.motorcities.com/contents/...300930112.html

And narrowing the rotors/housings means less unsupported e-shaft to flex. The longer rotary "stroke" will not necessarily lower redline.

I bet the runners above the 2ndaries are 6 port runners as cast in all plates and the plates shown are just milled for 4 port model. Judging by the shape of the runner they are doing something a little different than rotating sleeves this time and they are probably not ready to show it.

You can actually see the cast shape of the aux port runners in the pics of the rear plate behind the flywheel stacked on the 2ndary runners.

I see tiny primary injectors in the usual spot and bigger 2ndaries further into the intake stroke on the rotor housing for 4 injectors on the engine. Hopefully 2 more in the manifold for charge cooling density increasing goodness at full load.

Now if only they would make it with a 2 piece center bearing e-shaft for that 6-port model; and maybe even aux aux ports above the primary ports for the really high rpm that would enable.

Mazda are you listening? We will pay thousands more for a car w/ an extra thousand or four more redline :)

If I had to guess, I'd say it won't see forced induction for the first few years, if ever. I've heard horror stories about what happens to Renesis motors when they blow apex seals: without a peripheral exhaust port, there's not an easy place for the broken seals to get puked out of the motor, they stay inside and chew things up for a while. It would be a shame to risk the reputation of the new platform, I think it would be wiser to add another rotor than to add a turbocharger.

-s-

I noticed the single injector also and thought to myself "That's not really direct injection". Unless I'm wrong, direct injection is usually after most of the compression of the incoming air is already done

Direct injection has nothing to do with when during the cycle, it has to do with where, which is inside the working chamber, not in the manifold.

with a all alumnium motor, I think the "v8s only weigh 45lbs more" argument will go out the window:)

It's also bigger, so that'll make the parts heavier, probably not much lighter than a 13B.

I know it's an aluminum side housing but damn look at that dowel area at the oil pedestal! yeaaah buddy!
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my dick is hard! :D

okay, on a more serious note, i'm not really sure how i feel about the direct injection system. perhaps, it's a simple matter of my knowledge of all merits is lacking. however, i am very happy to see that Mazda has addressed the previous design flaws and potential weak points with this motor. as far as forced induction is concerned, i'm sure it would be nothing for them supply better ignition and supplement fueling to accomodate a turbo from the factory.

i'm very excited for this engine and i can't wait to get my grubby hands on one. :)

i believe you are thinking of a stratisfied charge rotary engine, in which there are two fuel injectors firing into the cumbustion chamber simutaneous to the combustion stroke. one fuel injector is a "pilot" light and the comustion process is initiated by spark. the real interesting thing is that the overall air/fuel ratio is lean for the combustion chamber, however the combustion process is locally rich.. resulting in a leaner cleaner burning engine..

im curious about this 16x injector setup, so if anyone has any information about it.. please feel free to share!!

Some of those tension bolt holes look pretty thin walled, so it might not hold up to well to dowel pinning or machining to accept larger studs. This may just be a pre-production display issue, as I'd immagine they'd want the bolts centered in the bosses.

That engine has 4 injectors that are visible. Two are in the current primary locations and 2 are directly on top. Not what we think of as true direct injection as they aren't by the spark plugs but Mazda has admitted that this is still an early prototype and they haven't worked out all of the issues with DI yet. What we see won't necessarily make it to production. At least not as we see it.

There are 6 oil injectors in the rotor housings. 3 per rotor. There is also extra casting where a 3rd spark plug could go as in the 787B engine. That dowel pin has been moved.

That engine is a 4 port. If you look at a 4 port Renesis, it's end plates look exactly the same. The animated end plate appears to show a 6 port internally which only creates more questions.

Yeah it isn't real DI which is what I noticed when I saw that. The prob with real DI is countering the compression with the injectors flow and then not having it all destory the injector itself dring the combustion process! A real DI rtary engine woudl have to have both injectors right between the spark plugs, secondary and leading. which woudl put alllll of the freakign plumbing and wiring on the right sid eof the engine and make things fairly annoying and complex to work on. In my opinion though they shoudl have on plug igniton coils. but that again would take up even more room on the right side.

Well, the point of direct injection on a production engine is so that it can be run very lean at low loads by having a rich pocket to ignite right next to the spark plug.

Still, you can only go so lean on the total mixture before power drops off so hard it cannot keep the car at freeway speed and it is a steep power drop off as you lean out.

Perhaps Mazda found that the natural stratified charge effect of injecting fuel at the 16X primary injector location into the vortice off of the leading rotor tip allowed for easy enough ignition at the lowest AFR that the car could maintain freeway speed at and any unused abitlity to lean it out more by "real" direct injection would be expensive wasted effort.

I stopped by the LA Auto Show today, but there were no rotary engines on display in the Mazda section. I asked one of the Mazda employees if he had heard about the 16X, but he hadn't. He mentioned that I wasn't the first person to ask him about it, and asked me to share what details I knew. We chatted for a while and I relayed all the info I could think of at the time; he seemed interested to hear about it. Still, it was a bit sad that there seemed to be such a lack of communication between Mazda Japan and Mazda North America.

There was a very clean-looking 1967 Cosmo there. They listed the curb weight, it was under 1000 kg.

-s-

i'm still puzzled as to why they are still doing the side port exhaust. you think they would've learned that more power can be harnessed with peripheral ports which would make the sale of the car more appealing to the young and old, and raise gas milage since it is much less restrictive. Old people dont want 8's because the gas mileage sucks, and young people (who care about going fast) don't want them because in order to get and real power outta them, you might as well do away with the whole engine!

its seems as if this engine may be better suited to boost than the original renesis.
correct me if im wrong but shorter housings mean shorter apex seals which means better resistance to breaking(less breaking points).
higher displacement generally handle boost better too i think. more surface area to cool means less chance of detonation and apex seals bouncing around.

you are correct about the apex seals, but someone correct me if I'm wrong - a high compression engine is a high compression engine. once that compression hits a certain PSI, no more boost can be pushed in. That is why the renesis is impossible to see much HP gain from compared to the previous 13b models.

Looks Nice

do you think a high compression engine (since its built to withstand higher pressures) would respond to insane amounts of boost with a water/meth injection kit and really good tune? just a thought

Does anyone know how wide these new rotors are? I have... ideas.

there suppose to be the same width as the 12a

The side exhaust is supposed to help with emissions to keep the unburnt hydrocarboms in the engine to get burnt, rather than being emitted as a pollutant. I think it was supposed to help milage too somehow. So while peripheral may be better for performance I don't think they can get it to pass smog any more.

yah but the rx8 still didnt get good gas milage. i think they need to figure out more on the peripheral exhaust. the side exhaust is better on emissions because they r able to send the unburned carbons back into the combustion chamber. the problem is, its a waist of power

dam, i didnt notice i just about said everything u did

While it may be "bad for power" the RX-8 does have the most powerful NA rotary ever produced from the factory, so a side exhaust can't be that bad.

As I've posted in other threads, there is more to power than just flow. Port timing has a huge effect. This is why the Renesis does so well. It's not because of the compression ratio or the intake manifold. The Side exhaust port timing is better suited to a street engine in terms of power, emissions, and as a match for the intake port timing. The Renesis doesn't even have port overlap and many claim this is needed for good power. It's not. There are many misconceptions about flow and timing. I actually wish Mazda would develop an all side port race engine.

I've heard 2 rumors but don't know for sure. One says 70mm like the 12A, and another says 75mm.

Put a 4.44:1 rear end in your car and add 400 lbs and see how good your mileage is! If you had a Renesis in your car, you'd get better gas mileage than you do now. You need to look at the entire package. The RX-8 actually gets comparable gas mileage to the much lighter and less agressively geared RX-7's.

I think the problem with a boosted renesis engine is the lack of proper stand-alone engine management. The hot ticket among turbo rx8 owners seems to be the the GReddy e-manage which as the greddy site says it best "as close to a stand-alone management system as you can get while maintaining the best features of a "piggy-back" engine management". The first key ingredients in any reliable high HP (350+ rwhp) rotary is stand-alone engine management.

Copied this from a mazdas247 post:

from a Japanese website

10A
e=15mm
R=105mm
b=60mm
Vh=491cc

13A
e=17.5mm
R=120mm
b=60mm
Vh=655cc

12A
e=15mm
R=105mm
b=70mm
Vh=573cc


13B
e=15mm
R=105mm
b=80mm
Vh=654cc

プロトタイプ

12A'（12A量産前に検討されたエンジン）
e=16.4mm
R=112mm
b=60mm
Vh=573cc

21A
e=18.5mm
R=128mm
b=85mm
Vh=1046cc

22A
e=18.5mm
R=128mm
b=95mm
Vh=1169cc

15A
e=15mm
R=105mm
b=90mm
Vh=737cc

And their guess for 16X is

16X
e=17.5
R=122.5
b=70
Vh=797cc

You need to redo your math.

13B = working displacement compared to a 4cycle engine = 2.6L
16X = working displacement compared to a 4cycle engine = 3.2L
20B = working displacement compared to a 4cycle engine = 3.9L

3.2/2.6 = 1.23 or 23% larger
3.9/2.6 = 1.50 or 50% larger

:dunno:

This should have better low end torque

interesting motor.. its definatly a prototype, the oil filter pedastal mount only has one hole, how do ya like that?!

i have some SAE papers with details on the side port design if someone is interested pm me.

Developed Technologies of the New Rotary Engine (RENESIS)

by: Masaki Ohkubo, Seiji Tashima, Ritsuharu Shimizu,
Suguru Fuse and Hiroshi Ebino. Mazda Motor Corporation

Sweet Jesus Love It

they're not going back to peripheral exhaust ports. side ports are the present and future. the problem is that mainstream hasn't caught up yet. porting, especially on the exhaust appears to be a bit tricky, but the bottomline is that these side port engines do their job better than the older design. i mean think about it. stockports on these engines are making what it would take streetporting or forced induction to make on the older engines - with the same fuel. i'm sure it's just a matter of time before we all have a bag of tricks for making more power.

yeah, i was curious about that, too.

exactly! :D

Maby the oil then goes to the oil cooler? all pressure is regulated pre-oil filter or post oil cooler?

this is the second time i heard someone say that the older 13b need to be streetported to make as much power as a renesis. thats basically saying that the the ports on a renesis is the same size as a stock n/a 13b. well if u believe this, than your wrong. the port on the renesis is about 3 times bigger than the older
13b. but guess what, the rx8 is only making a little over 180rwhp. go to the rx8 forums where they show there actuall dyno numbers and u will see that most of them with mods r only making around 180 to 190rwhp. now u also have to consider that the renesis has lighter rotors with more compression, lighter
e-shaft, better intake design, less restrictive exhaust, and all new technology around it. the rx8 barely make any gains with mods. some guy were only making like 5hp off an exhaust. so why would that side exhaust be considered any with hp? older 13b's make more power on a streetport