Another Radial - this time 18 Cylinders

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wirralcnc

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I also have a full set of dynamotive merlin castings. I purchased last summer so must of got one of the last sets.
I think you should make a start on this great engine and then I can use all your knowledge from the build when I finally get round to building mine.
 

mayhugh1

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Or maybe we could do a 'group' build?
 

mayhugh1

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His work truly is remarkable. I found his webpage sometime ago when I was researching the Merlin and drooled over his model. He must do his own castings not to mention all the research needed to come up with a set of plans from which to work. In the video what you seem to hear most is all those internal gears. He probably included every single one of them. He is definitely one of a kind. It would be an honor to spend a month with him in his shop watching him work. - Terry
 

wirralcnc

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What about a pratt and whitney r1830 radial from castings 1/6 scale. Bruce satra made the castings and I believe paul knapp has taken over.
 

mayhugh1

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What about a pratt and whitney r1830 radial from castings 1/6 scale. Bruce satra made the castings and I believe paul knapp has taken over.
I have trouble with those really tiny parts nowadays. I have trouble seeing them, my fingers can't hold them, and someone keeps coming into the shop to hide them from me. - Terry:wall:
 

digiex-chris

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I'm so glad I got caught up with this thread. Thanks for all of your detailed diagnostics and math, it's really helping us that are getting started designing an engine from scratch! I really love the sound of the thing. Very nice!
 

Mattsta

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Hi Terry

I'm attempting to model an 18 cylinder radial in Pro/Engineer, similiar to Solidworks. This is just a bit of fun. I don't have the skills to even begin being able to produce one.

As you can see from the attached images, my connecting rods are too short and approaching TDC, the piston is still only half way up the bore. I'm doing this purely from photographic reference as I don't own Hodgson's drawings. The PCD of the journals on the crank and master rod is all correct so I must have the length of the master rod and slave rods considerably shorter than they should be. What length are they?



 

petertha

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If the engine is allowed to sit a few days, there is also some oil from one or two lower exhaust pipes whose cylinders were left standing with open exhaust valves. If I were starting the engine build over, I would include pushrod tubes.
Hi Terry. Early on the build thread you mentioned not bothering with pushrod tubes (or maybe you just preferred the exposed pushrods to see motion etc). Later in post #374 you mentioned tubes might be a good idea in hindsight. Can you elaborate? I didn't quite get the connection between the oil/exhaust & the tubes. Just overall cleanliness of grit getting into the pushrod ball end interfaces? Or would tubes somehow be used to contain lubrication? How is any lubrication contained on the upper pushrod ends in any event? (what prevents them from running dry?)

I could have sworn there was a pic/vid showing tubes on your engine, but now I cant seem to find. Maybe I'm mixed up with this build. (I'm having an issue accommodating the 3d pushrod/tube geometry, I think that's what these ball-in-socket ends are all about).
https://plus.google.com/photos/111407870409657577971/albums/5278304464310065009?banner=pwa

Anyway, just wondering if you had thoughts or since modded your engine in that regard.

thx/Peter
 

mayhugh1

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Peter,
I didn't use pushrod tubes on either of my radials. What you may be remembering was the small diameter hypodermic tubing I added to tbe pushrods on my 18 cylinder radial in order to build up their diameters for cosmetic reasons. If I were doing it over again I would include pushrod tubes because most of the oil leakage over time comes from the lower lifter bushing clearances. - Terry
 

mayhugh1

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Don,
I extended the design of the 9 cylinder radial plan set that I purchased from Agelessengines.com to come up with my 18 cylinder radial. Ageless also offers plans for an 18 cylinder engine. - Terry
 

ChooChooMike

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WOW, JUST WOW !!! th_confused0052 I've seen smaller models (5/7/9 cylinders), but haven't seen a running 18-cylinder.

None of us are worthy !!! :bow: :bow:

Mike
 

Stieglitz

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Hi Terry,
Totally gob smacked,lost for words,just have to watch.
Thank you for for taking me on the journey.
Cheers
Allen.
 

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