Randall Cox Open Column Six

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

cfellows

Well-Known Member
Project of the Month Winner
Joined
Aug 25, 2007
Messages
3,890
Reaction score
715
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
 
Love the exhaust burble. And that open distributor is kind cool, too.
 
WOW!!!!

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

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

Andrew
 
Boy that thing is pretty neat!!!
gbritnell
 
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
 
how do the connecting rods survive?
do they have valleys that hold grease.

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

Regards,


Chuck

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

Latest posts

Back
Top