Anzani Y-Type

[cwelkie]

It's done!
I was fortunate enough to acquire a set of castings for the 1/4 scale 1910 Anzani 3-cylinder radial last autumn and spent the winter/early spring working on the engine.  As many of you know, the castings included the crankcase halves, rear cover, carburetor and intake pipe elbows.  I used cast iron for the integrated cylinder/head design.

Of all the components, the cylinders were the most challenging.  I used Alibre to finalize the cylinder and head details before beginning the machine work to ensure I had achieved a reasonable facsimile of the original cylinders to work with the Chenery design.  They aren't exact scale but worked out fine.

The internal gears required to drive the exhaust cam were all shop-made to drawing.  The gears used in the ignition distributor however were DP48 pinions intended for radio control model cars.  The pitch diameters and ratios all worked out by adjusting tooth counts as required.  Modifications to the hubs and thicknesses were all easily achieved in aluminium "potchucks".

The rings were made using the "no heat" method of turning and oversize cylinder, cutting the gap and final diameter sizing on a mandrel.  Fortunately, the engine has very good compression after a few short runs already so the rings and valves are sealing nicely.  I did pressure test each cylinder as the valves were lapped to be sure of a good seal.

I did take a number of photographs during the work so if there are any specific questions or curiosities, please ask and I'll try to help.  In the end, it was a satisfying build.

https://youtube.com/shorts/r3BsHbPG68o?feature=share

[cwelkie]

Some photos taken during construction ...

[RReid]

That's quite an interesting engine, and you've done a bang-up job in building it. Seems to run great in the video, and sounds just right too!
Congratulations!

[Jo]

Well done.

This is a direct link to your engine running:

<a href="https://www.youtube.com/watch?v=r3BsHbPG68o" target="_blank">http://www.youtube.com/watch?v=r3BsHbPG68o</a>

In case anyone is confused trying to find the Les Chenery Y type Anzani drawings, Les only drew up the Fan type, the Y type is a variation on these drawings which was initially done by Mike Coles who also provided the castings (Mike also did castings for the W and a different variation on the Fan types). Mike has since given up doing castings  there is still the odd set kicking around with various casting hoarders

The drawing for the iron cylinder was done by  it will come to me 

Jo

[Roger B]

Splendid     

The video has unfortunately loaded as a 'short' which YouTube seems to do now and then 

[mikecole7]

     Well done Charles, that's a very nice engine, it runs great better than mine.

[Admiral_dk]

Looks and runs fantastic - you should be very happy with the result     

Per

[Twizseven]

Sounds and looks fantastic.  Well done.

I must try and look at the part done one I have on the shelf.

Colin

[cwelkie]

Thank you everyone for your kind feedback.  This was indeed a satisfying project, especially after having the valves seal way down in that deep hole.

At the risk of adding confusion rather than clarity here is the origin story for my engine:

• The engine drawings were purchased from John Chenery (Les's son)
• Additional information came from the serialized article by Les Chenery in Model Engineer magazine
• The aluminium castings came from Mike Cole

I redrew the cylinder/head based on the original design that used a separate cast aluminium cylinder and pressed in cast iron liner using Alibre Atom 3D.  Some changes were made to make the job easier (e.g., no taper on the fins and fin size/spacing) with a one piece cast iron unit.

One significant advantage of redrawing the cylinder didn't come to mind until work began. Given that I tried to do the CAD as if I was machining the part (e.g., started with a big lump and cut away the bits that didn't belong), I could do shop drawings that showed dimensions in a series of "workshop steps".  This reduced drawing clutter and possibility for error.  In the end, I'm happy to say that I only needed to make 3 cylinders 

[Jo]

 I forgot Les C also did a Y type     

It would be nice to see those cylinder drawings. The one I have was drawn up by Brian Fairey. It is done in two pieces with a thread joining the head to the main cylinder. Photo of a cast Iron and Les's original Ali cylinder attached.

Jo

[RReid]

Given that I tried to do the CAD as if I was machining the part (e.g., started with a big lump and cut away the bits that didn't belong), I could do shop drawings that showed dimensions in a series of "workshop steps".

Although sometimes that's how they evolve, I've never consciously done drawings that way. I think it's a great idea!

[Kim]

Congratulations!  That's a great running engine! 
Kim

[Jasonb]

That has turned out very nicely. Radials don't usually do it for me but there is something about the Anzanis that I like.

[Zephyrin]

sounds great, just like the real one, fabulous engine !
congratulations.

[cwelkie]

Thanks again everyone.
I came across a few notes I made during construction.  I've included them here in case they are of value for someone else.  Please remember - your experience may be different but it wouldn't hurt to check and compare ...

Drg.113 Intake Chamber Cover Plate OD shows 2 11/16” diameter but Drg.102 Rear Crankcase recess for this plate shows 2.625” … Drg.102 is correct (or at least that's the dimension I used).

Drg.102 Rear Crankcase shows 2.312” centre distance for crankcase vent holes but this distance only applied to one side for the casting I had (the cast bosses are not symmetrical around crankshaft or cylinder).
Also, drilling full diameter full depth for these holes is not required and will cut into the 2.625” internal diameter. Drilled and tapped for 3/8” and finish with 1/8” into crankcase (even 3/32” would be adequate).

Drg.103 Rear Cover shows a clearance depth to 0.094” for the 0.812” diameter cutaway (cam idler gear clearance). This is inadequate if the gear assembly is made to Drg.140 with a total height of 0.254”. As drawn total relief is 0.140” on Drg.102 (Rear Crankcase) plus 0.094” on Drg.103 (Rear Cover) for a sum of 0.234”.  There is adequate material on the rear cover to go 0.125” deep providing 0.265” for the gear assembly.

Drg.103 Rear Cover does not provide an “ideal deck height” for the contact breaker mounting shelf. For ideal gear mesh this should be 0.909” below the crankshaft centre line. (This applies if the contact breaker is built as per Drg.147 Contact Breaker Assembly and the mounting holes are positioned as per Drg.103 (Rear Cover.)

Drg.103 Rear Cover shows contact breaker mounting holes spaced 0.687” by 0.437”. Drg.147 shows the mounting holes to be 0.75” by 0.437”. The hole locations from Drg.147 (i.e., 0.75") will work for both. Place the forward mounting holes in the bracket as dimensioned on Drg.103 and locate the rear holes toward the rear of the shelf by 0.75”.

Cylinder flange counterbores on the crankcase are too large in diameter. As drawn they intrude into the hold-down stud holes and could be reduced in diameter to be slightly more than the cylinder flange outside diameter.

The rear tailshaft bearing is specified with a 0.156" thickness.  There is adequate room to use a (more common) 0.188" thick bearing.

Distributor drive and internal gears can be made from off-the-shelf model car pinions (DP48 12T, 18T and 24T) without changed centre dimensions.