# 1/4 Scale, Four Rotor PP



## Ethan D (Feb 13, 2014)

Hey Everyone,

I couldn't help myself, i had to post my project! Well the design stage of my project for now. 

Currently i'm not in the position to start building it, because i'm getting married in 2 weeks, and saving for a house and lastly.... stuff to kit my future garage out with... SO.... i thought ill spend this time planning and designing the little Wankel. 

The little engine is being designed at 1/4 scale and based around a 13B from a RX4. Im planning to put as much detail as possible into this little motor to make it look just like its bigger brothers. 

The motor will be approx 40cc, but that is still to be confirmed through calculations. 

So far i have drawn up standard n/a housings (excluding exhaust ports), Center plate and currently drawing up the front plate. Below is a little description of whats been included in the current finished parts.

Housings:
They include all details of the copied 13B housing, I have included oil and water galleries, and cylinder chroming, excludes the exhaust port. Im still yet to decide whether ill cast the peripheral port into the housing, or modify the housings just like the guys do with the real ones..... 

Center Plate:
Again all detail has been copied from the real center plate. I have included oil and water galleries. 

The housings, center plates, front & rear plates and other covers will be casted using various methods. The parts will be very fine detail so I think ill get some parts of the molds 3D printed.

As this is my first engine, it might be a long and educational build. Feel free to comment and suggest ideas. I know its going to be a challenge but that's just the joy of this hobby

Here are some pictures of the model so far 

Showing the inlet & exhaust side.












Section through housing.




Section through center plate.




More to come...
P.s... Sorry for the bad quality pictures. I dont have any detailed rendering with my software 

Cheers
Ethan


----------



## Heffalump (Feb 13, 2014)

Will this be completely CNC? It looks great!


----------



## Ethan D (Feb 13, 2014)

Heffalump said:


> Will this be completely CNC? It looks great!



Hey Heffalump, 

Thank you 

Im going to try to keep it roughly 50/50. Im going to machine the E-shaft and the extra lobes at front and rear, the counter weights, the rotor ring gears and stationary gears, finishing casting and other parts that i cant think off currently will be manually done, i think it would be quite fun. Some casting molds and core molds will be hand done, but otherwise cnc or 3d printing will be used for them.


----------



## Heffalump (Feb 13, 2014)

That's great - I can't wait to see your progress


----------



## Art K (Feb 13, 2014)

Ethan,
I don't know a lot about rotory engines but from reading I understand that Mazda did exhaustive research on the Wankle concept. If I recall they ended up adding carbon to combat excessive wear. Have you given any thought about what to use as apex seals?
Art


----------



## barnesrickw (Feb 13, 2014)

I used to watch a lot of Auto Cross.  The RX7's were always smoking at the end of the day when driven hard.  I say for authenticity sake, let the seals be close enough to work, and let the smoke fly. 


Sent from my iPad using Model Engines


----------



## Ethan D (Aug 16, 2014)

Art K said:


> Ethan,
> I don't know a lot about rotory engines but from reading I understand that Mazda did exhaustive research on the Wankle concept. If I recall they ended up adding carbon to combat excessive wear. Have you given any thought about what to use as apex seals?
> Art



Hi Art K.

Sorry for the late reply. I have had alot on the past few months. I recently got married, job change etc. So life has been crazy!! Haha

I'm going to keep my apex seals, side seals and corner seals basic to start out with untill the engine runs. So ill make them out of cast iron. After that, if she runs well I "might" look into getting some apex seals made out of Silicon nitride (Si3N4).


----------



## Ethan D (Aug 16, 2014)

barnesrickw said:


> I used to watch a lot of Auto Cross.  The RX7's were always smoking at the end of the day when driven hard.  I say for authenticity sake, let the seals be close enough to work, and let the smoke fly.
> 
> 
> Sent from my iPad using Model Engines



Haha, I like the way that sounds!!


----------



## SixSixSevenSeven (Aug 16, 2014)

This will certainly be an interesting project to watch, haven't found any other wankel engine projects myself.


----------



## Art K (Aug 17, 2014)

Ethan,
You might consider a single rotor to prove the theory and work the bugs out, then expand to 2, 3, 4. By the way congratulations on your marriage!
Art


----------



## Ethan D (Aug 17, 2014)

Art K said:


> Ethan,
> You might consider a single rotor to prove the theory and work the bugs out, then expand to 2, 3, 4. By the way congratulations on your marriage!
> Art



Hi Art. 

Thank you very much.

Thanks for that suggestion. That's a very wise idea. I shall do exactly that.
For a single rotor I won't even bother putting all the detail in it. Just the basic geometry and critical things like oil and water galleries. 
Thanks again
Ethan


----------



## kadora (Aug 18, 2014)

Hello Ethan
It is my dream to build wankel engine . i have two 
vintage wankels RC engines sitting on my shelve.
I always admire ingenious principle of this rotary beast.

I read on some forum /CNC zone??/very long thread written by a CNC guru 
there he describes machining small wankel engine but he was not sucessful
at the end.

Anyway keep us informed on your progress your thread will be my favorite.
Thank you


----------

