# Anzani 3 cylinder radial - compressed air



## cfellows (Apr 30, 2011)

I'm considering this engine finished, although, like most of my engines, I will most likely always be tweaking and changing things a bit. For those of you who might think my engine mount resembles the lid of a crypt with a tombstone, my wife already pointed that out to me. Wasn't my intent, just turned out that way.

The curved bottom of the base was inspired by some of the excellent models made by Tom Hall. It is made from a 1.75 inch diameter steel pipe, split lengthwise into quarters. The ends were then mitred and all pieces welded together. Lots and lots of grinding and sanding got it to resemble a casting rather than being built up by welding. The top of the base is made from 1/4" cold finished steel, rounded on all edges and welded to the mitred frame. The upright is made from 3/8" thick aluminum angle. The base took me 3 full days to complete. Usually I just throw something together, but since my models spend a lot of static time being admired on the shelves of my study, I decided to make it "pretty".

One bit of serendipity is that this engine idles and runs kind of rough, missing a lick now and then and generally sounding like it needs a tuneup. I find this to be amazingly like many of the videos of old radial engines running on youtube. Almost sounds like it has a 3/4 cam in it. It's also kind of hard to start sometimes, kicking back and endangering my prop spinning finger. Not sure how I managed this bit of realism, but I'll take it!

In retrospect, the cam assembly, lifters, pushrods, rocker arms and valve assemblies added a huge amount of complexity to the build compared to the much simpler valving mechanism of my opposed 4. But, perhaps the visuals and the irregular running make it all worth it. Now if I could just get it to backfire occasionally...

























































This is my first video. I noticed later, after I had uploaded the video, that one of the pushrods was dislodged from the lifter, so the engine is only running on 2 cylinders. 

[ame=http://www.youtube.com/watch?v=VbuiCROHeVY]http://www.youtube.com/watch?v=VbuiCROHeVY[/ame]

This is the second video, taken with a different camera and with the engine running on all three cylinders.

[ame=http://www.youtube.com/watch?v=bIYcx4-uyYE]http://www.youtube.com/watch?v=bIYcx4-uyYE[/ame]

As a recap, the engine has a bore and stroke of 5/8" x 5/8". It is 4 stroke in operation with each cylinder "firing" on every other revolution. The cam has 2 lobes 180 degrees apart and turns at 1/4 the RPM of crankshaft. Two sets of gears, each reducing the speed by 1/2, are positioned so that the cam sits on and is concentric to the crankshaft. The propeller is made of from a steel bar, 1" x 1/4" x about 10" long. 

Chuck


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## Diy89 (May 1, 2011)

Good Job Chuck. That's a nice runner. Sounds good to, and i really like the base! :bow:


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## Captain Jerry (May 1, 2011)

Chuck

Great job, from conception to completion. Every one that followed this must have learned something. I know I did. Thanks for taking the extra effort to show us all this unique engine.

Jerry


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## ozzie46 (May 1, 2011)

Excellent job Chuck and I agree , the sound is great. Thanks for the ride along and the instruction. 

 Ron


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## b.lindsey (May 1, 2011)

Chuck,
Beautiful job on the build thread and the finished engine. It sure have a nice sound to it as well !! Well done!

Bill


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## maverick (May 1, 2011)

She's a looker Chuck. And the sound! I giggled through the whole video.
Very nice job.

Best regards,
Mike


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## Tin Falcon (May 1, 2011)

great work one again chuck the base is a work of art
 Tin


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## kustomkb (May 1, 2011)

Another great design, beautifully executed.

Sounds awesome!

Congratulations Chuck.


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## joe d (May 1, 2011)

Chuck

Another good-looking, good sounding engine. I like the base too!

Joe


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## larry1 (May 1, 2011)

Chuck, Great work, and a great sound.  Really enjoy your work. and how to's.  larry


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## bearcar1 (May 1, 2011)

What an outstanding looking and sounding engine Chuck! BRAVO! In one of your last updtaes towards the end of the build, you had an image of the engine pretty much done except for the intake plumbing and I wondered to myself, "how in the name of Zuess is he going to do that?" Well now we know the rest of the story (yeah I know, P. Harvey) and I like it! Truly a creation of art and a labor of love. Well done. :bow:

BC1
Jim


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## GailInNM (May 1, 2011)

Very nice Chuck.
Gail in NM


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## jct842 (May 1, 2011)

That is one nice outcome. sounds just like I would expect if it were running gas and had 3 sparkplugs. John


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## awJCKDup (May 1, 2011)

Great looking engine Chuck and sounds incredible!!!!
Well dome

John


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## bradbyname (Jun 19, 2011)

That is absolutely fantastic. Well done. just be sure to keep your fingers clear of the propellor!


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## awJCKDup (Jun 19, 2011)

That is a nice engine Chuck, very nice indeed........I'd like to build one of those....... you know, if had some plans or something.......hmmmm.....hey Chuck do I remember in your thread, that you might put some drawings together and post in the Plans?......Hmmm.....probably would make a nice project.......hmmmm.......well, maybe I'll hint around or something.......hmmm.....Nice job Chuck and it sounds GREAT!!!.....hmmmmm......hmmm.....Well if anyone else would like to hint around to Chuck about plans, now might be a good time........Hmmmmm.....hmmmm
Good job Chuck
 John


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## lathe nut (Jun 19, 2011)

that is sweet, sure sound like a real on to, you do good work and really think them though, hope I make it to retirement going to do what you do, build and enjoy, hope to be as good as you, thanks for sharing, Lathe Nut


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## cfellows (Jun 19, 2011)

Thanks, all, for the kind comments. Unfortunately, drawings will not be forthcoming for the engine, at least in it's current form. The rocker arm mounts, the inlet manifold, and some other parts got too complicated near the end and I'm not real happy with them. The overhead valves work reasonably well, but are very sensitive to adjustment. They also have a tendency to stick.

I'm considering making some serious changes to simplify things. I may get rid of the overhead valves, push rods, and complicated cam gearing in favor of a rotary, tube valve arrangement like I used on the opposed 4. It would make things a lot more reliable and a lot easier to build. That might result in some drawings for other folks to follow.

Chuck


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## rustyknife (Jul 13, 2011)

That is very very cool. Looks great, I love how you cleverly designed the base.


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