# Randall Cox Open Column Six



## cfellows (Nov 30, 2011)

This is the six cylinder version of my Open Column Twin. It was designed and built by Randall Cox and was featured in a two-part build article in Issues 1 and 2 of Model Engine Builder. I first saw Randall's engine at the GEARS model engine show in Portland, OR in 2006. I loved the engine and decided to build my twin and pattern after Randall's design. I'm now thinking a 3 cylinder inline version would also be pretty neat.

This is the first video I've seen of this engine. Randall emailed me a couple of days ago with a link to the video, so I thought I would post it for the HMEM group. 

https://www.youtube.com/watch?v=d11nI3BQMeM

Chuck


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## rleete (Nov 30, 2011)

Love the exhaust burble. And that open distributor is kind cool, too.


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## lazylathe (Nov 30, 2011)

WOW!!!!

That runs so smooth!!!
Love the exhaust sounds!!!

Thanks for sharing the link, i have never seen an engine like that before!!

Andrew


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## gbritnell (Nov 30, 2011)

Boy that thing is pretty neat!!!
gbritnell


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## ShopShoe (Dec 1, 2011)

Wow!  Neat! :  Cool! :bow:

--ShopShoe


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## kuhncw (Dec 1, 2011)

Chuck, thanks for posting this video. 

I also noticed the final video of your twin cylinder open crank. That twin will really lug. Is that a waste fire ignition setup?
What is the flywheel diameter on your twin?

Regards,


Chuck


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## Speedy (Dec 2, 2011)

how do the connecting rods survive? 
do they have valleys that hold grease. 

cool engine, would like to understand the open aspect of it!


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## Swede (Dec 3, 2011)

It is a beaut, and you can tell the craftsmanship is superb.

I don't think this is a replica of any particular engine. The big flywheel will allow for smooth, low-speed operation, and like any low-speed IC engine, you can get away with hand lubed (or greased) friction points... or, maybe he made a lot of use of roller bearings, which retain lube well. Split roller bearings are a top-shelf addition to any engine like this.


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## cfellows (Dec 4, 2011)

kuhncw  said:
			
		

> Chuck, thanks for posting this video.
> 
> I also noticed the final video of your twin cylinder open crank. That twin will really lug. Is that a waste fire ignition setup?
> What is the flywheel diameter on your twin?
> ...



Thanks, Chuck. It is a waste fire setup, both cylinders fire at the same time. The flywheels are 6" diameter with 1" wide rims and are really heavy.


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## cfellows (Dec 4, 2011)

Speedy  said:
			
		

> how do the connecting rods survive?
> do they have valleys that hold grease.
> 
> cool engine, would like to understand the open aspect of it!



I think he just squirts a little oil on them periodically.

Chuck


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## cfellows (Dec 4, 2011)

Swede  said:
			
		

> It is a beaut, and you can tell the craftsmanship is superb.
> 
> I don't think this is a replica of any particular engine. The big flywheel will allow for smooth, low-speed operation, and like any low-speed IC engine, you can get away with hand lubed (or greased) friction points... or, maybe he made a lot of use of roller bearings, which retain lube well. Split roller bearings are a top-shelf addition to any engine like this.



There's no roller or ball bearings used in the engine. The crankshaft is built up from hardened steel dowel pins and flatstock. You can't see in the video, but the flywheel has radial fins around the outside and acts as a centrifugal blower to cool the engine cylinders through the cowelling.

Chuck


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## Longboy (Dec 29, 2011)

This engine appeals to me too with open crankshaft. Very smooth! :bow:


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## popnrattle (Jan 2, 2012)

Amazing engine and great video. Love the engine note when he puts it under a load. I keep going back to the vid as it always make me smile. Thanks for posting.


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## pcw (Jan 2, 2012)

very nice engine. the open colum is very nice. i think at shows it draws more intention than a fully enclosed crankshaft. people like to see stuf move aint it? 
Pascal


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## solver (Jan 2, 2012)

Sweet it sounds yes. Looks not bad either. 

As mentioned, open column makes it even more interesting.

Small engine huff'npuff'n, it's just magic :bow:.


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## terrywerm (Jan 14, 2012)

That is really neat - don't know what else to say. And watching it is a real treat for certain.


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