# 6-cylinder radial steam engine done and running



## crueby (Jan 8, 2011)

Just finished a new 6-cylinder radial steam engine - my own design, with a 1/2" bore and 1/2" stroke. I've built a number of kit engines (Stuart, PM Research, etc), and this is my first foray into building from scratch. I've always been intrigued by radials, and thought it would make a great project. Turned out well, even with the many many disassembles/reassembles to get it right! 

The size was mainly determined by the size of the aluminum block I had for the crankcase, and the size of the bar stock I had for the cylinders. It uses slide rod spool valves bored through the same block as the cylinders - this kept the design simpler. A goal of it was to be able to make the whole thing without any castings (except for the flywheel, which I already had a spare of).

Got it running this morning, hooked up to an air compressor. It runs quick at 40 pounds, and slows down to just ticking over at 5-8 pounds. 

I've done a photo build log, with plans, and am uploading that to the downloads area. Here is a photo of it, and a link to a video of it running. Really fun project!

Video:
[ame]http://www.youtube.com/watch?v=oHfb2sPbHPs[/ame]


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## 1hand (Jan 8, 2011)

crueby,

Thats a looker  

I think you did a great job, a very nice looking, and running radial.

Looking foward to the build log and Plans Thm:

Matt


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## 1hand (Jan 8, 2011)

OH ya, heres your Karma buddy!


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## kustomkb (Jan 8, 2011)

Great job, looks and sounds really nice!

Thanks for the plans.


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## cfellows (Jan 8, 2011)

Great looking, nice running engine. Nice job!

Chuck


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## Mr VG (Feb 3, 2011)

Very nice!! Looks great and sound great also. Will have to look in the downloads for this one!! 
Mr VG


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## jpeter (Feb 3, 2011)

Looks really good. 
I'm curious though. IC radials generally have a master rod. Yours seems to be missing that feature. Is that the nature of steam engines to not use a master rod? Fill me in.


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## bearcar1 (Feb 3, 2011)

I too applaud you for your efforts as well as sharing your labors.

BC1
Jim


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## Maryak (Feb 4, 2011)

crueby,

Great looker and runner. :bow: :bow:

Best Regards
Bob


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## navigator (Feb 4, 2011)

Nice job. I think that it is going to go on my "to do" list. Really impressive


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## Mbergmueller (Feb 4, 2011)

OOOoooooooooooh, nice. And your own design even!


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## ironman (Feb 4, 2011)

Great looking and sounding engine.  Thm:


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## crueby (Feb 8, 2011)

jpeter  said:
			
		

> Looks really good.
> I'm curious though. IC radials generally have a master rod. Yours seems to be missing that feature. Is that the nature of steam engines to not use a master rod? Fill me in.



This one does indeed have master rods, one for the piston crank and one for the valves. Without it, the crank bushing could get turned too far and jam up. I locked in the rods for the first piston/valve by putting a post off the bottom of the rod that fit into a hole in the bushing - it is held in place by a bolt just like the other rods, so from the outside it may not appear to be locked in. I had photos of it in the build log.


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## crueby (Feb 8, 2011)

ironman  said:
			
		

> Great looking and sounding engine. Thm:



Thanks! It was a fun project to do. Currently I'm working on a variant of the horizontally opposed air engine that cfellows did. I'm using the same type of valving, but making it a V4 configuration. Also, rather than the geared valve, I am going to try making it a chain drive, since it will be quite a bit farther away from the crankshaft, up level with the top of the cylinders. If that doesnt work out, I'll go back to a geared drive, maybe with a third one in between for the spacing.


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## cfellows (Feb 8, 2011)

Glad to see you're going to try a V4 arrangement of my horizontal opposed. Should be an exciting build project. Had you thought about using a timing belt for the valve?

Chuck


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## crueby (Feb 9, 2011)

I did consider that, but had trouble finding lengths that would fit, plus the sprockets seemed to be very pricey. I thought I'd try the chain first - chain is cheap, and I can make the sprockets to the size needed. Easy enough to change that out later if the chain doesnt perform.


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## ejcheli (Feb 19, 2014)

I know this thread is a few years old but I wanted to say... WELL DONE!!

Also, I am going to try and follow your plans and build my own for a school project. If successful, I will post results on this forum.

Edit: Started a thread: http://www.homemodelenginemachinist.com/f31/6-cylinder-radial-22742/#post243813

Eric


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## rogerwest48 (Dec 30, 2021)

31/12/2022 - Great model and I am following your plans, thankyou so much for this access.
As is usual, for me, I draw them out first to ensure that I understand the design and the energy that you have put into it.
Unfortunately, amongst some missing dimensions on the plans, there is the pitch circle diameter (PCD) of the piston crank, 2-56 screw holes is missing.
You have stated that it is a 1/2" / 1/2" stroke / diameter that seem at odds with the plans for the above!
My wife often tell me I am wrong....but!
Please, can you enlighten me, and others as this is a critical measurement.


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