I want to do a front wheel drive rotary project as soon as my current five projects are done. Or at least after they all run. No project is ever really done.

Looking out at the freshly fallen snow, I can't help but yearn for a tiny FWD econobox with a not-so-tiny secret under the hood. I've already questioned my sanity doing a 20B project, so I'm feeling confident about attempting a wrong wheel drive project.

A rotary baja or Suzuki Samurai would be great some day, but I've got to start a little smaller and work my way up. Pretty much any small FWD car from the '80s would do, but I've had my eye on a few models that are special to me. I won't bore you with details.

I've narrowed it down to either an Isuzu Imark/Chevy Spectrum (as I've mentioned on this forum in the past) or a Chevy Sprint (the 1.0L 3 cylinder predecessor of the Geo Metro).

If I choose the Imark, it'll get a 12A or a 13B. If I choose the Sprint, I'd like to try to queeze a 12A in it, but I may have to go with a single rotor 13B (from Atkins, most likely).

Of course all of this requires a transaxle that has the right dimensions to work with a rotary. If it can come close to handling the power of a rotary, that would be great. Even the failure-prone Fiat X1/9 FWD tranny (which was converted to RWD use in the X1/9) can handle up to 150HP (150ft lbs torque at 5252 RPM), if applied without dumping the clutch or other abusive acts. A CV shaft that pokes out at least 7" away from the intput shaft ought to do it.

Believe me, I already have an outlet for burning rubber, should I need it (or I will soon). This is more of a 'can I do it?' sort of project for when my others are all running. So far, one down, four to go. The one running will have its carb removed and placed on a rebuild to break it in before I add the performance carb.

Any thoughts of FWD rotary power?

 

Jeff,

Thought about a Subaru Justy? They came with 4 wheel drive. I wonder if it would handle the power?

Speaking of power. I have the bits to stack a single rotor 12A. Could be a start to you project.



-billy

 

I actually had a dream that we had a 13B in my friend's integra.

Anyways, sounds like a fun project. I guess the hardest part is trying to find/make a tranny adapter.

 

what about an audi 80 coupe ? they have longitudinal engine but are FWD ... just like an RO80.

I would have though a 13b would have been a fairly simple swap with mating the transmission being the only obvious hurdle I can forsee at this point.

Plus I have always like the shape of Audi 80 coupe's (probobably somthing to do with the quattro version)

Mike

 

old toyota tercels a lognitudal with FWD
i bet you could get a 13bt in there

 

Thanks for the responses, guys. Yeah, those longitudinal FWD cars are way too easy. The Mazda R130 Luce was the exact same way. I'd still rather do a transverse rotary.

It still boggles me that they killed the whole 13A FWD idea. It seems like part of Mazda wanted the 13A to fail, thus causing the FWD rotary concept to fail. This is of course speculation, but no other FWD rotary was ever produced; especially during FWD's peak of popularity during the early '90s. Perhaps Mazda's money troubles are partially to blame.

The Audi is a nice car. My uncle's cousin had one. I've considered a Subaru, but all it needs is a VW-like adaptor (from KEP) and you're nearly done without much work. The Integra is an Acura, right? Then it'll have an engine that spins backwards compared to like 90% of all other manufactures. I think the Corvair had the only other counterclockwise running engine that most of us would know about. Anyway, a rotary powered Honda is possible, if you use a genuine NSU rotary because they spin backwards!!! Yep, the carb is on the bottom and the exhuast ports are at the top. Call Atkins, because that's where I last saw any real NSU engines.

bwaits, are you talking about the custom E shaft, and short tension bolts that are required to build a one rotor engine? Or are you talking about a good used 12A rotor, housings, and front and rear irons? If so, I've already got some marginal parts that I'd like to try. My 13B rotor needs a new bearing, and the '76 13B rotor housing is missing a little chrome (but way less than some I've seen which still ran ok). It would be great if I could use those 13B parts I've got. I also have a spare rear counterweight and could get a front counterweight (1757?) quite easily. The only things I'd need are front and rear irons and a custom E shaft. The custom E shaft would be the most expensive part. I believe I could make my own tension bolts if I had a 10mm x 1.0 die. I may actually have one in a large tap and die set I got recently. I'll have to check... nope. I just have 1.25 and 1.5.

Hey, which stationary gear needs to be modified? I think the rear one does. This is how I imagine the engine going together. The front stationary gear is normal, as is the front rotor of a 12A, or either one for a 13B. The rear stationary gear may need to be trimmed to clear the rotor bearing. I haven't tried test fitting it yet, but it seems necessary. Or maybe not because the rotor bearing is centered in the rotor fore and aft.

 

How about a rotary powered Ford Fiesta?
They look cool, they handle great, weigh next to nothing (1760#). The only downside is their lack of power and rather small brakes, but that can be remedied. Anyway, I'm going to have a Fiesta body to give away soon, once I yard the motor out of it. It's yours if you want it.

 

Well, this is new to me if it means that the NSU rotary spins differently from a Mazda rotary. Mazda rotaries have been swapped into Ro80's a number of times and I have never heard that this should imply having the Mazda rotary to spin in the reverse direction.

Please let me know if I have misunderstood something!

BR, Bo

 

I meant to say it was a Wankel engine that spins counterclockwise, not an NSU engine. I'm sorry. I get them confused (thinking about it, I can see why). Anyway, it was a genuine Wankel two rotor engine.

 

Jeff,

What I have is the custom e-shaft with lightweight flywheel and front counter weight that are balanced together. I also have all the irons that have been professionally resurfaced. I have two 12a rotors that I put away years ago - I guess they are good or I would have tossed them.

You would still need a rotor housing, front cover, custom oil pan, custom intake manifold - I do not have those parts. I was going to just cut down stock tension bolts. Have not thought much about the stationary gear side of it.

I was going to use this stuff to get some dyno results and try to get a single rotor allowed in SCCA for D Sports Racer. You are welcome to make an offer for all or some of it. It is just sitting around right now.

I did talk with Atkins while pursuing this and found something out - I will PM it to you.

-billy

 

Wankel has not really produced engines. The engines were all build by NSU, except for the later experimental things. But those don't belong in a car, they should be in a museum.
This is an NSU engine (mine):






They are not really different then our Mazda engines, structuraly seen.
FWD with transverse engine was done by Citroën (GS birotor) using a Comotor engine (based on Ro80 engine, which is pictured above) Comotor was the joint venture by NSU and Citroën, btw.

 

just to add:
http://www.der-wankelmotor.de/Fahrze...n/citroen.html

As for Wankel engines named "Wankel":
http://www.der-wankelmotor.de/Motore...nkel_gmbh.html
The firm Wankel Rotary was started by Felix Wankel, but sold to LONRHO (UK) in 1972, Felix Wankel quit in 1976. After this he'd start his Wankelstiftung and TES (a sort of engineering lab) and one of his employees would buy back the Wankel Rotary GmbH firm from LONRHO in 1992. Later this firm was bought by the Wankel AG (still in business I believe)

 

Are you sure about that? As far as I know the normal GS had a longitudinally mounted boxer-4 with a gearbox arrangement similar to the Ro80, including the inner-mounted disc brakes. It appears most unusual if Citroën would design an entirely new gearbox/FWD setup instead of making a simple swap using the existing FWD design.

BR, Bo

 

check this: http://hem1.passagen.se/chapron/

The transverse engine is the reason why the car is wider then an ordinary GS.

I have some good pics of the engine/gearbox subframe/craddle in books, but cannot find anything on the net.
Some info is available, but no good engine shots.

 

you can see a little something here:
http://www.vanrootselaar.nl
go for wankel engines, and the pic of the GS engine.
This one:


you can see the engine, and the axle/driveshaft for one of the wheels, running next to the engine.

 

Wow, that's all very interesting. I'll give it some thought.

 

Hi rotary emotions,

Thanks for the link to Niklas' Motor Page!

I have checked it out and I found what I have been searching for for a very long time: the PROOF that the GS Birotor had a transversely mounted RE, see the attached picture.

Still, I really wonder why they came up with this design. The only reason I can think of may be the fact that the RE is too tall compared with the flat-4 so it just wouldn't fit longitudinally.

BR, Bo

 

Wankelguy, thanks for the offer, but a can't get any other cars until all mine are running. It could take a while.

bwaits, although I'd prefer a single rotor 13B, I haven't fully discounted a single rotor 12A yet. I'll keep your offer in mind.

By the way, when you said the front counterweight and flywheel were balanced together, are you talking about machining material from both so they offset the weight of only one rotor? Or do you mean they're a factory matched set, and otherwise stock? You see, I've got a theory about that, and the stationary gear stuff too. Isn't it possible to simply get a set of front and rear counterweights (from Mazdatrix or whatever) for whichever rotor I plan to use, and not have to machine them at all? It seems logical.

Also, the way I'd build a one rotor engine would keep the front stationary gear stock, and maybe trim the teeth from the rear gear to keep it from chewing the inner strengthening ribs of the rotor, if necessary. Or since 13B gears are 5mm longer, I could probably get away with a 12A gear on the back because the extra 5mm is gear teeth only. I believe the bearings are in the same position on 12A and 13B gears.

Anyone know where I can pick up a 10mm x 1.0 (fine pitch) die? It'll need to have the common
stock size. I think it's like 1" hex and fits most die drivers/wrenches (sorry, I'm kinda new to thread cutting).

rotary emotions, that's cool that you have an NSU engine. It looks a lot larger than the 'Wankel' engine. Atkins had two one rotors and one two rotor. Say that two times fast.

I think those NSU Wankel one rotor engines Atkins had were like the ones in those gokarts pictured on the der-wankelmotor website. Heh, that twin engine unit looks like it has two twin rotor engines. A gokart powered by four rotors! That'd be nice to have.

KKM, that sure is a nice find! Now to find a good transaxle to make it a reality with a Mazda engine.

 

Yep, I wanted to post that pic too, but then my computer crashed...
I'm not sure why they did this the way they did. But the NSU solution isn't really that good: all the wheight lies in front of the front axle.
The GS boxer isn't really shorter or anything, so the height may have been a reason. But if you look at the KKM of the NSU it ain't really that much less wide then it's long. Maybe we should keep in mind that the GS birotor really wasn't a GS: it was a prototype testing a new car (the CX) Citroën planned a 3 rotor version for the CX, and mounting that in front of the axle would have become really nose-heavy.

 

rotary emotions, are you saying the engine was mounted way out in front of the transaxle? Man, I hope I won't have to do that.

 

Jeff, the go-kart indeed has twin engines!
Anyway, NSU made single rotor engines (for the Wankelspider) so it may be a Wankel spider engine you've been looking at?
And BTW, I don't just have the engine, I have the Ro80 to it aswell
The engine isn't really a lot larger, but it looks more "square". The engine had an internal oil cooler (the "box" in front) which makes it look heavier.
As for a single rotor: a second rotor will balane the first, which is why 2-rotor engines can get away without balance-shafts, and get very light flywheels (yet Mazda didn't think we need light flywheels: they seem to have slapped iron monsters to each engine they build, in order to keep the car heavy enough! )
A single rotor will have to be balance way more carefully. I'm not sure if it's needed to go single. A 12A is very small, and people already put it in a Mini, so it should fit any engine bay!

 

yep, it was. Check here: www.ro80.nl

and this one (pressphoto)



But due to the entire concept, the Ro80 was a perfect handling car. Yet, I'd try to go for the Citroën setup.

 

That's great that you have an Ro80!

Yeah, I'd like to use my '73 12A if possible because it has a smaller bellhousing than '74+, and it's got a nice street port. I also have a set of used '83-'85 rotors for it so the rotating assembly will be decently light. I still have this urge to put a rotary in a Sprint because it came stock with a three cylinder. The engine bay may infact be too small for a two rotor engine.

One thing I find curious about the four stroke three banger is it has 1.5 bangs per rev. A single rotor has 1 bang per rev (not counting trailing or the 180º leading sparks hehe). A piston engine has only 180º of a power stroke while the rotary has 270º. However, the 3 banger's 1.5-per-rev translates to 270º! This means both engines would have roughly similar looking power pulses at the same RPM. This little fact intrigues me. It is probably the single driving force for me to do a one rotor project and drop it into a Sprint. Not to mention the '85 model is very light. I'd even do an '86 model if I can't find an '85.

So, rotary emotions, do you think a stock set of counterweights will be fine for a single rotor engine?

Interesting picture. Disc brakes mounted on the tranny. At least that keeps more of the weight towards the middle of the car; always a good idea.

So you'd try to go for the Citroën setup instead? Could you tell me if the Citroën setup had the CV shaft near the intake and exhaust ports? All I have here is Mazda stuff, but it looks like the CV shaft needs to be at least 7" away from the input shaft, in order to clear the side of the engine. Even further to clear the manifolds.

 

Well, that's the way most FWD cars with longitudinally mounted engines are designed. Although it looks "nose-heavy" it is possible to install almost any kind of engine in this place wihtout any problems, e.g. Audi/VW has offered this concept with inline-4, inline-5, V6, V8, W8 and W12.

Other solutions are indeed possible, e.g. NSU designed the (VW) K70 with the engine on top of the differential/ front axle. Honda offered an inline-5 with the differential mounted on the side of the engine with a driveshaft arranged through the engine block.

You can also swap the location with the gearbox in front of the engine as e.g. in the Renault R16.

BR, Bo

 

I know it's "normal" to install engines that way, but a transverse mount engine would still be a lot less nose heavy, I'd reckon. Now, of course, on a FWD car, a little extra wheight on the front wheels doesn't really harm. My Mazda 626 ('96) daily driver has the engine transversely mounted, but I find it has very little grip (even on quality tires) under moderate to hard acceleration, due to the nose lifting.