Tiny I.C. Engine

[Stefan-K]

Hi

A little update on the progress. The new Conrod is finished and i made a new piston with a tighter fit as well. It is about 0.04 mm (or 0.0015 inch) smaller than the bore. Tried to start the engine but no success! It sure popped a few times but it didn`t run. I found out the problem is the Sparkplug. It sparks outside the engine with some "blackouts". And that was getting worse. At least it sparked only sometimes. Seems to me that the plug has an internal short circuit somewhere. Maybe the corian insulation is too thin. Have to make a new one........

Stefan

Attached you find some pics.....

 

[AussieJimG]

Maybe cleaning the spark plug with clutch and brake cleaner would help. It only takes a little bit of dirt to create a track on the plug.

Jim

 

[GailInNM]

Stefan,
Looks great!
I had one plug that failed after about 10 hours running, as I recall. It would spark OK outside the engine. I have a tester made up that I can pressurize
the plug with with shop air to about 40 PSI. It has a acrylic window in it so I can view the gap. It would not spark when under pressure. I assume that there was a thin crack in the insulator within the body of the plug.

This was an early plug and the center electrode was a tight fit in the inslulator so I suspect that it cracked, or started to, during assembly. All my later plugs I made with an easy fit between the center electrode and the insulator and got a good epoxy bond between them. Never had a problem with any of them. A friend has one of my early "Tiny" engines in a locomotive and the spark plug has failed. He has about 30 or 40 hours on it. He is sending me the plug to examine. I had given him a spare plug and it cured the problem he was having. He is in Canada so I have not seen it yet.

I am getting ready to make some more plugs for some more engines to go in two Gauge 1 locomotives. Engines are about 1/2 done and am drawing the locomotives. The locomotives are Baldwin Mechanical trench locomotives as were used in World War 1 for moving supplies behind the lines on 2 ft gauge tracks.

Gail in NM

 

[putputman]

Stefan,
I am curious about that third gear under the crank shaft. I don't recall seeing a set up like that before. What is the purpose of that gear.

Looking forward to seeing another Tiny running.

Arv

 

[Stefan-K]

Hi Jim , Gail and Arv

Cleaning the Plug with brake cleaner was the first thing i did, but it didn`t help. I remember, as i turned the corian insulator, that the thinnest part (2mm) broke off. I glued the parts together hoping it might work. But as Gail already said, a little crack in the insulator will allow the High Tension to jump over at that point. We are talking about 5 to 15 thousand volts or more, depending on the ignition system and coil you are using. I am using a selfmade CDI system which runs on 6 volts and puts about 400 volts on the primary side of the ignition coil and that leads to an output of aproximately 15 K volts. Once it jumped over it will create a very little path of carbon in the crack from burning the material. And this will conduct the electricity even better. That explains the behaviour of the sparkplug. I´m sure that this was the reason for the failure.
Arv, you asked for the reason of the third gear. Well, i use it for the ignition timing. On the inside of the gear you can see a narrow ring of Plastik (Delrin) wich contains the small magnet. I set the ring on the axle and clamp it on with 2 little screws. So i can set the timing where ever i need it. I attached 2 Pics to make it more visible. I wanted to make smaller gears, but i have only one set of Modul gear cutters (m 0,75). And these were the smallest gears i can make with them.
Hope the new Plug works as expected....
Keep you updated.....

Stefan

 

[Stefan-K]

Hi together

I have good news.

I finished the new Sparkplug, put everything tentatively together and gave it a try. I don`t use a liquid gas carburator, cause they are difficult to build in these small dimensions. And they often make problems. I use a vapour carburator instead.
What can i say, It runs. I´m so happy. All the hours in the shop pay off when you see it run the first time.

I attached pics from the new sparkplug and try to upload a video of the running Tiny.

Here´s the video link: http://youtu.be/-TvEvwgvQxs

Here`s another link about testing the new Sparkplug: http://youtu.be/nn1kUhR41ko

Stefan

 

[AussieJimG]

Congratulation Stefan, it runs well.

Jim

 

[putputman]

Congratulation Stefan, another great little runner. This is the first one I have seen use a vapor carb. That should solve the problem of standard carbs vapor locking from too much engine heat transferring to the carb. If you get a chance could you show photos of the vapor carb along with some dimensions. I think I would like to try it on my engine.

 

[Stefan-K]

Thanks a lot.

The Vapor Carb i used for the Tiny test run is from another engine. I attached some Pictures. The dimensions i used here: The Glass tube has an inner diameter of 22mm and 24 mm outer dia. and is 80 mm long. it is glued with a loose fit to the aluminum side walls with Loctite 648. On the right side is a 5mm brass tube for the air inlet. The air is sucked in and goes straight down to the surface of the gas. On the left side is another 5mm brass tube which goes to the engine via an "extra air" valve to adjust the mixture. The dimensions are not critical at all. You can even use a small jar to test it. I found most of my information on Jan Ridders website, who had the idea. Here`s a video link about the Vapor Carburator:[ame]https://www.youtube.com/watch?v=xWBWhRZiZ9E[/ame]

And here is the link to Jan´s website with the Carburator.:
http://ridders.nu/Webpaginas/pagina_benzinedamp_carburateur/dampcarburateur_frameset.htm

He will send you a free plan if you ask him for it via email.

Since i`m using the Vapor carb i never had any Problems with fouling or wet Plugs.
Hope this helps

Stefan

 

[Stefan-K]

@ Gail
I´m just watching the pictures on post #128. The neat exhaust flap you made ! I like it very much and want to build one for my Tiny. Can you please give me an idea on how you made these parts?

Stefan

 

[GailInNM]

Stefan,
I thought I had some detail photos of the exhaust flap posted but I mayo not have. I have a set of parts here of one for an upcoming project that I can photograph and post but I won't have time to do it for a week as I have house guests here for a while. I can include some notes about it then.

Your Tiny looks and sounds good. Congratulations on a successful build.
Gail in NM

 

[Stefan-K]

Gail

That would be nice. Thanks a lot. I still have a lot of work to do on the Tiny to make it look good. The exhaust flap is one of the latest things i can do.


Stefan

 

[GailInNM]

Stefan,
Here is a quick JPG of the parts drawing with just elementary dimensions. Just make the operating arm so the flap can not open enough to stay open. Flap part needs to have enough weight to be self closing. I had to adjust the stop part of the arm a little bit to get the most pleasing action.

If you need more information let me know.
Gail in NM

 

[Stefan-K]

Hi Gail

Thank you very much for the nice drawings. I appreciate sharing the drawings and i`m sure they will help me a lot. I´m just brooding here about how to design the Tank/Vapor Carb for the Tiny. Have to keep in mind that the Carb needs about 15 to 20 cm² (gas)surface to work and vaporise enough gas while the air flows through it. So the minimum size is limited. I wanna use glass to see the action inside but keep the focus on the running engine. I have one design in my mind that i will try to draw and post it here to see what you and all the others think about it.

Keep you updated.....

Stefan

 

[Stefan-K]

Hi
Here's a little update on the progress. I decided to build the Tank and post a picture rather than drawing it first. I also finished the exhaust with the flap. These little parts took me almost a day to build them.
Stefan

 

[GailInNM]

Looks good Stefan. You do nice work.
Gail in NM

 

[GailInNM]

Stefan has finished his very nice model of Tiny and the finished model is shown in the Finished Projects section with more photos and video. Sample photo shown here and the link to the thread showing the rest is here:

http://www.homemodelenginemachinist.com/showthread.php?t=24158

Very nice Stefan.
Gail in NM

 

[GailInNM]

I was just up on YouTube to answer a comment on the video of the first TINY that I built. It is amazing how much attention the Tiny's have attracted from the general public. My first video has over 70,000 views and is still plugging along at about 500 views per month. And, there are a lot of other videos of Tinys in a variety of configurations from other people on YouTube and other places.

Thanks to Arv (Putputman) for getting this whole thing started.
Here is a link to the video of my first Tiny.
https://youtu.be/mLn7xG8vuPQ
Gail in NM

 

[AussieJimG]

Hi Gail

I´m just brooding here about how to design the Tank/Vapor Carb for the Tiny. Have to keep in mind that the Carb needs about 15 to 20 cm² (gas)surface to work and vaporise enough gas while the air flows through it. So the minimum size is limited.

That is a beautiful engine Stefan and I like the carby too. Where did you get the information about the required surface area? Is it related to the swept volume of the engine?

Jim

 

[Stefan-K]

Hello Jim

Thanks for your nice comment. I have all my information about the Vapor Carburator from Jan Ridders Website. I think he invented the principle of this carb. Here is the link to his website: http://ridders.nu
He lives in the Netherlands and is a very nice guy. You can see many videos of his engines running with this carb. He explains the vapor carb in detail on this site:
http://ridders.nu/Webpaginas/pagina_benzinedamp_carburateur/dampcarburateur_frameset.htm The site is in dutch and english language.

Many greetings Stefan