Tuesday, January 1, 2013


Somewhere around August or September while browsing the HEME website, I happened to see a picture of Jan Ridders version of an Atkinson Cycle engine that intrigued me. Although it uses the Atkinson Cycle, it is not a scale model such an engine. This one has a timing belt driven overhead cam shaft. Not vintage at all, but still interesting. I happened to mention seeing the picture to correspondent friend Reg Ingold of Australia, and would you believe by return email he sent a PDF of the plans for the model. I happened to be out of a project at that time and thought what the heck, it is as good a candidate as any, so I started gathering materials.
Just happened that materials to build it were already on hand, so it was a matter of cutting them out and start making chips. Progress was slowed by the fall cleanup (leaves etc.) and care taking responsibilities, but never less it proceeded at a rate about as fast as a snail tied to a stump, and parts slowly started to emerge.
                        Here are just a few of them.
The ignition is powered by flashlight batteries using a coil from the magneto of a Lawn mower type engine. The breaker points, not shown, are a Micro switch operated by a cam on the crank shaft. The spark plug is also home made. It is a spare left over when I built the 4 cylinder Panther Pup engine.
This engine is equipped with a Vapor Carburetor, where the intake air is drawn through the fuel tank, where it picks up vapors to run the engine. While this concept dates back to some of the very first gas engines ever built, it is new to me. I'm not sure how good it works. At the time of this posting I have not yet had the engine running, so I'll have to do a bit more fine tuning, but I feel confident that it will work. Videos of them show them working very well.
      During construction I took a short video while turning the engine by hand. It can be seen much easier how the mechanism works turning at that speed than running anyway.


Nora Henández said...

Hi! i found this blog by searching on Google about designing an Atkinson Cycle motor, I've been searching for a while, and I haven't found something really definitive. I'm right now a student of mechatronics engineering, and I have a project due to next week about the design of this type of motor, and I'd like to know if you would share with me the plans for the model, I promise it's not for commercial purposes and would be exclusive for my use. Thanks for your consideration. PS. Sorry for my bad English, I'm form Mexico.

Mark Smith said...

I'm interested in your ignition system. Is there any way that I can get more information on the coil. I've been using automotive coils and they're rather large. Thanks