Anzani

[ken rector]

Dave
Au contraire, the Anzani Fan Type looks quite elegant.;-) 

Checkout the proportions of the finned and un-finned portions of the cylinders and the shape of the finned portions.  Also, the proportions of the crankcase and the inlet tubes.  Further, notice the shape and proportions of the plenum that attaches the carburetor to the intake tubes.  I know from experience trying to reproduce it that it is not easy to make curved bulbous pieces like that look good.

Anzani was a builder of motorcycle engines and the fan type was developed from his motorcyle V twins.  The basic crankcase and timing gear setup was the same in the fan type.  The third cylinder provided additional horsepower needed to power an airplane with very little additional weight.  There is some thought that the fan type was chosen instead of a Y type because of concerns over oil collecting in the lower cylinder.  That may be as those engines used a total loss lubricating system.  But it seems more obvious that the fan type was just an extension of the V twin that he knew very well how to build.  Anzani   produced the Y type only a year or two later and continued to build radial variations on that design with up to 20 cylinders for many years.

The rods don’t cross over in a master slave configuration and that design could work in a fan type.  Note, the Anzani fan type is just 3/5ths of a 5 cylinder radial.

The three cylinder fork and blade is certainly not a bodge.  The connecting rods are designed with appropriate strength for the stress to which they are subjected.  The stress is not increased because there are three rods instead of two.  Obviously they couldn’t use this system in engines with a greater number of cylinders and they did come up with a different idea for the Y type engines.  There have been different ways to solve this problem but that doesn’t mean the three rod fork and blade was a poor idea.  Poor ideas in airplanes don’t last and Anzani sold a lot of these engines.

[Jo]

I've been having a scribble and I think I have the drawings for the missing W type and the 6 Cylinder Anzani parts

These have not been checked yet but let me finish a couple more little engines and get some space then I might be tempted to fondle those castings 

Jo

Edit: Removed out of date drawings. For latest see below.

[Jasonb]

Busy day at the office?

Have you got a 3D of them all assembled, I'm having a job seeing how they will not hit the crankshaft. "U" shaped cutout is 28mm dia but conrod forks are 16mm from pin to outer edge and will be a bit longer still on teh diagonal?

J

[Jo]

Those are the W type rods and the extended 6 cylinder crankshaft. The W engine has the same crankshaft as the Y type, the six cylinder engine the same rods as the Y type 

Jo

[crueby]

Wow, that is quite a lot of moving parts in a very compact arrangement.

[zeeprogrammer]

Wow, that is quite a lot of moving parts in a very compact arrangement.

Moving? I don't see anything moving. 

[crueby]

Wow, that is quite a lot of moving parts in a very compact arrangement.

Moving? I don't see anything moving. 

Move ypur monitor back and forth.


 

[Jasonb]

Wow, that is quite a lot of moving parts in a very compact arrangement.

Moving? I don't see anything moving. 

Move ypur monitor back and forth.




 

No, No, No you need to turn your monitor round and round as they are Radials

[crueby]

Wow, that is quite a lot of moving parts in a very compact arrangement.

Moving? I don't see anything moving. 

Move ypur monitor back and forth.




 

No, No, No you need to turn your monitor round and round as they are Radials

I sit corrected!!   

[Jo]

Mr Anzani has got back to me with his original drawings: He recommends that the outer diameters on the big ends should be slightly bigger on the W type 

And the cut away on the inside of the Six cylinder centre throw needs to be extended out to 32mm diameter to allow for clearance for the straps part 117 which need to be reduced in length down to 30mm to clear the cut away.

Jo

[Jasonb]

See I knew that clearance needed to be bigger

Is the crank built up or cut from solid ? If solid that undercutting of the 30mm dia recess will be interesting!

J

PS you probably only need the other bit 30mm not 30m

[Jo]

See I knew that clearance needed to be bigger

Except that the conrod you were on about was for the other engine 

Jo

[num1bryanp]

Hello all,

You folks have done a great job of building what looks like a 1/4 scale Anzani 3 fan radial motor, and now a 6 cylinder.

After looking at my Subaru twice, I cannot fit a 1/4 scale Bleriot RC plane inside. After thinking about the problem the answer presented itself, just build a 1/6 scale version. Of course, this is also true for the motor which led me to you folks. Do you think it is possible to build a working 1/6 scale Anzani fan radial motor?  A Bleriot needs the look and sound of a real gas motor.

The motor would not need to be exact scale, therefore I would not need custom sand castings at this point. I would just mill the motor body out of a block, and if it works I could soften the outer surface to give the casting look. If I could use a modern carburetor it would be nice, and of course, using any proven ideas for the mechanics that would help simplify the motor would be greatly appreciated!

I have been wanting a bigger project to work on, but advice before starting would be helpful.

Thanks,
Bryan

[Jo]

How many working model engines have you made... None of the Anzani's are beginners engines. The scale was chosen as the parts are not too fiddly. 

Jo

[num1bryanp]

Hello Jo,

This would be my first engine!  (Not running away yet)

I would start by getting it into Autodesk fusion 360, for me, this will the had part. I tend to just have a lot of drawings lying around, this is okay for one-offs but in this case, with 3 or more of most parts, I will try to use the CNC mill where I can.

Thanks,
Bryan