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.

































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...

 

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!

 

my dick is hard!

 

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-