Brian does Ridders flame eater

[brian Rupnow]

Nothing intended by links other than showing a couple interesting designs, and the very free running of the single cylinder version, despite an ordinary-looking piston like yours.

Did the other engines use the graphite piston?

I really aren't sure.

[J Tiers]

Nothing intended by links other than showing a couple interesting designs, and the very free running of the single cylinder version, despite an ordinary-looking piston like yours.

Did the other engines use the graphite piston?

[brian Rupnow]

Jerry--I have watched about 20 different videos of this exact engine running, and they all seem to run effortlessly. Some guys have even arranged them as twin cylinder engines. I have 12 running "steam" engines which I run on compressed air, 12 running gasoline engines, and one running Stirling engine. I am much happier when they run right away without a lot of re-jigging and head scratching. I have a family "get together" to attend today (Bunch of grandchildren with birthdays close together), so I'm doing something relatively quiet and "clean" until my good wife comes downstairs and tells me it's time to go.

[J Tiers]

Here is a crazy one:

https://www.youtube.com/watch?v=Mw1W7f_WtaM

And one that appears to run extremely freely. It may be a commercially made version, but has a very different valve.

https://www.youtube.com/watch?v=n1Tpgc8LwiU

[brian Rupnow]

And here we have a video of "running in" the engine. Even though the crankshaft and big end of the con-rod are riding on ball bearings, there is more "drag" than I like caused by the piston sliding in the cylinder (a lapped fit) and the valve rod sliding in it's drilled hole. I have coated everything with oil and will let it run for an hour, then put the entire engine in a solvent bath to wash out any oil and/or metallic residue. It is running very slowly in the video, I doubled the speed after it had ran for a few minutes.

https://www.youtube.com/watch?v=_NeaicL1dQc&feature=youtu.be

[Willy]

:-) Yes and so is Diamond carbon (also very pure) If you read a bit about the various forms that carbon can exist in you'll soon wonder how you could have ever thought that idea. :-)
...lew...

Wow, I guess I've been extremely lucky that the carbon brushes in my electric motors haven't chewed up the commutators on the armatures in a nano second. And yes I do realize there are various forms of carbon, hence my question.

[Lew Hartswick]

would the initial use of a sooty flame aid in coating this interface with carbon in order to reduce friction? My thinking is that since graphite is basically carbon it may help..

:-) Yes and so is Diamond carbon (also very pure) If you read a bit about the various forms that carbon can exist in you'll soon wonder how you could have ever thought that idea. :-)
...lew...

[Willy]

Just thinking out loud here and hopefully not meaning to derail Brian's thread.
However since the largest portion of friction in the engine is going to be generated between the piston and cylinder, would the initial use of a sooty flame aid in coating this interface with carbon in order to reduce friction? My thinking is that since graphite is basically carbon it may help.
Not having any experience in this area or having a back to back comparison to prove or disprove this idea I was wondering if this may be of any benefit.
Thoughts.

Great progress already Brian, it's looking good. I've always wanted to build one of these so I'm eagerly waiting for this little jewel to be running.
Thanks again for taking the time to document another build.

[Sparky_NY]

Maybe the idea of the graphite piston was for it to be self-lubing without any liquid lube?

If so that is a clever idea. I'm not sure that all forms of graphite are as slippery as one might assume, though. The EDM graphite does not seem slippery.

Exactly.... I looked over the plans because I have been tempted to build one for a long time. Another advantage of graphite is no corrosion from the condensation. (same reason for the stainless cylinder)

[J Tiers]

Maybe the idea of the graphite piston was for it to be self-lubing without any liquid lube?

If so that is a clever idea. I'm not sure that all forms of graphite are as slippery as one might assume, though. The EDM graphite does not seem slippery.

[brian Rupnow]

-I oiled everything up because turning this thing over by hand you could feel the "roughness" of bare metal scraping on bare metal. I am sure that the oil will add some "stiction" and perhaps prevent the engine from running. I have half a mind to hook an external drive to the flywheel and let it run with oil on everything for a couple of hours just to wear down any "high spots", then flush all the oil away with laquer thinners.

[Sparky_NY]

Its Boyles Law at work. Also, the term Vacuum is used as a absolute when in fact there are degrees of vacuum. Anything below atmospheric pressure can be considered a vacuum. The hot air being drawn in is NOT compressed like in a regular IC engine so any cooling lowers the pressure (Boyles law again). The heat element is probably not going to be near as hot as the alcohol burner so when cooled to ambient there will be less differential, aka less power in the case of this engine, I doubt it would work unless it was extremely hot.

[brian Rupnow]

I think you guys are probably right. I just did some googling trying to confirm my concept of consumed oxygen creating the vacuum and couldn't find anything to support it. Seems like perhaps it is purely heat differential.

[sid pileski]

I agree with JT. It’s about heat differential. And atmostphic pressure pushes the piston back up the cylinder to start the cycle again.

[brian Rupnow]

Jerry--Everything I know about Stirling and flame-sucker engines has been learned in the last two months. I am not absolutely certain of my facts, but this is how I interpret things based on a lot of reading.---Brian