Open Column Twin

[cfellows]

That's a seriously nice engine. After 30 years of building steam engines, I'm still not quite sure that my skills are up to taking on something like that

Thanks! From a machining standpoint, there's not much difference between gas engines and steam engines. Gas engines are just more complex, since they have the additional worry of fuel and ignition systems.

Chuck

 

[cfellows]

After a sebatical of a couple of months I got some more done on my open column twin. Actually, I was having a problem getting the valves to seal and I've been pouting about it for two months!

I finally solved the problem tonight. I dressed the back of a small, dremel mounted grinding wheel to 45 degrees to match the valve seats. I then made brass bushing that fit inside the valve guide and provided the right inside diameter for the shank on the dremel grinding wheel.

I pushed the brass bushing into the valve seat from the bottom side, then pushed the shank of the grinding wheel up through the bushing so the dressed back of the stone rested in the valve seat. Using a variable speed electric drill I spun the stone until the seats were nice and shiny all the way around.

I put the engine all back together and I now have good compression on both cylinders! Maybe I can get this thing finished up and running.

 

[Florian]

Hi cfellows

I know that for grinding in the valves of engines, they use grinding compound. You can also use some toothpaste (the one with abrasive particles). Then you put some paste on the valve seat and grind the valve in during some minutes (depends on how good it was prepared before, on what materials were used for the valve and its seat and on what you are using for grinding compound)

Florian

 

[cfellows]

I know that for grinding in the valves of engines, they use grinding compound. You can also use some toothpaste (the one with abrasive particles). Then you put some paste on the valve seat and grind the valve in during some minutes (depends on how good it was prepared before, on what materials were used for the valve and its seat and on what you are using for grinding compound)

Yeah, I tried that initially, but the valve seats were too far off to lap. I needed the grinder to get the seats trued up more. I should probably go back now and lap the valves in.

Chuck

 

[Bogstandard]

Hi Chuck,

That engine is coming on real well.

A real crappy pic here, but if you can just see, I embedded the transistor into a groove machined into an ali block using epoxy, to protect it. The ali bock was then fitted to an arm that could pivot around the disc with the magnet in it. This gives the advance/retard for when the engine warms up.

Jerry Howell is a great chap to deal with, I had trouble working out the size of disc required and how many magnets, but he soon put me on the right road by explaining it all, and the tim system works great. Fires up every time.

John

 

[raym 11]

Hi Chuck;

Nice engine!
I don't have the know how to design my own.

A while back we discussed the carburetor on my Upshure Twin. I have since built the Ridders foam carb and it runs the engine mucho better. I am just finishing a scaled up foam carb with a rectangular section verses the cylindrical version. I an hoping it will take less adjustment when the fuel level changes as the liquid /vapor interface area will remain constant.

Will be interested to know how your engine runs with the carburetor shown.
What is the block with the horizontal hole located on the manifold between the air/fuel mix block and the heads?

Ray

 

[cfellows]

Hi Chuck;

Nice engine!
I don't have the know how to design my own.

What is the block with the horizontal hole located on the manifold between the air/fuel mix block and the heads?

Thanks for the compliment. The block you mention is just part of the intake manifold.

Chuck

 

[cfellows]

I started this engine back in the fall of 2007 and finally got it running. The past couple of days, I installed some points, a condenser and a dual wire coil I got from Jerry Howell. Hooked it up to a vapor carb and finally got it started. Clearly got lots of tuning to do to get it to run the way I want, but it's a start!

[ame=http://www.youtube.com/watch?v=jZTSmiSO-oE]http://www.youtube.com/watch?v=jZTSmiSO-oE[/ame]

Chuck

 

[chucketn]

I know nothing about IC engines, but, why the different diameters on the left flywheel?

Chuck in E. TN

 

[cfellows]

I know nothing about IC engines, but, why the different diameters on the left flywheel?

Chuck in E. TN

It's all the same diameter. It has a V-groove in it so I could run it with an electric motor and a tiny v-belt to break it in before I tried to start it. Also works to hook up an electric starter if it's hard to start.

Chuck

 

[Brian Rupnow]

Very nice, Chuck. I'm glad you found a way to get the valves to seat.---Brian

 

[steamer]

Great looking engine Chuck! I really liked the twins. with the cranks at 180, what's the sound like?

Sorry no speakers.......

Dave

 

[cfellows]

Very nice, Chuck. I'm glad you found a way to get the valves to seat.---Brian

Thanks, Brian. I just hooked an electric motor up to it and run it for about half an hour with no fuel or spark. That seemed to bed everything in.

Great looking engine Chuck! I really liked the twins. with the cranks at 180, what's the sound like?

Sorry no speakers.......

Dave

Thanks, Dave. The sound isn't where I want it yet. It's running too fast, it's only firing most of the time on one cylinder, and the one cylinder is missing a lot. I want it to eventually have the syncopated sound of an old John Deere or a two cylinder Lister. But I have to get it hitting on both cylinders and running a lot slower. I probably will have to change over to a carb rather than the vapor carb. I'll be trying a few things, including adding an outer ring to the flywheels to make them heavier. Stand by...

Chuck

 

[b.lindsey]

Chuck, that is one beautiful engine !! As has already been said...awesome!!

Bill

 

[GailInNM]

First pops are wonderful. Congratulations. Thm: Thm:
Gail in NM

 

[Maryak]

First pops are wonderful. Congratulations. Thm: Thm:
Gail in NM

Me too. :bow:

Best Regards
Bob

 

[gbritnell]

Hi Chuck,
Nice job on the twin. Are you going to stay with the vapor fuel setup?
George

 

[cfellows]

Hi Chuck,
Nice job on the twin. Are you going to stay with the vapor fuel setup?
George

Thanks, George. I'm having a problem with the vapor carb splashing fuel up into the intake tube and flooding the engine. If I do stay with the vapor carb, I'll have to make a taller one so the liquid fuel is well below the fuel line to the engine. I also have several model airplane carbs that I could try to adapt, although I think they are all too large. The venturi on the smallest is .25" or more. Another option would be to duplicate the carburetor designed by Randall Cox for his Open Column Six engine featured in Model Engine Builder since my Open Column Twin is based on Randall's design.

Chuck

 

[cfellows]

I added a half inch thick steel ring to each of the flywheels today. I figure I probably more than doubled the weight. They are now 6" diameter. Turned the rings to an interference fit then heated them as hot as I could get them with my mapp gas torch. I left a small shoulder in the bottom of each ring as a stop for the flywheel to rest on. The first one went real nice and dropped right in with only a little nudging to get it straight. Unfortunately the second went in about half way and stuck. Luckily I was able to use my 20 ton press to coax it into place. I had to work my way around the rim a little at a time and it took me a full 15 minutes to drive it home. But it is now in and straight. This picture was taken before I started cleaning them up. I'm doing some tapering and rounding to make it look like one integrated piece.

Chuck

 

[starnovice]

Chuck,
Did you ever get this project finished? Glad to hear you made it to the GEARS show I'm sorry I never got to meet you there.

Pat Wicker