Horizontal Air Cooled Engine

[Brian Rupnow]

So, as of this morning I have parted off 13 cast iron rings from my new stick of iron from Wisconsin. The o.d. is equal to the bore of my cylinder. The i.d. is calculated so that when installed there will be 0.003" radial gap between the inside of the ring and the bottom of the groove in the piston. The rings have been deburred and had the edges broke on one side---they were deburred and sanded on the exposed side before they were individually parted off. They are all "over thickness " by .004 to .005 and that will be addressed when I dress the side which is not deburred on a cast iron surface plate with a sheet of 600 grit aluminum oxide paper on it. They have all been examined under a magnifying light and the "bad side" marked with a black marker.

[Brian Rupnow]

The rings have been fully deburred and taken down to the correct thickness. They have been split using a very sharp cold chisel, then the ends have been filed so that when inserted into  my cast iron cylinder they have a 0.004" gap. Here they are mounted on my heat treat fixture and spread over a 0.131" drill and ready to go into my heat treat oven for 4 hours at 1100 degrees. The extra rings which didn't fit on the fixture will be appropriately identified and kept for a future build.

[Brian Rupnow]

This is a picture of the rings on the heat treat fixture after 4 hours at 1100 degrees. The fixture and the rings look like crispy critters, but some scrubbing with a brass bristle brush and  liquid dish soap cleans them up to a much better look.

[Brian Rupnow]

This is the rings after removal from the heat treat fixture. They will still require a bit of clean up, but they are essentially finished. Note that each ring has now taken a "set" to the 0.131" diameter of the drill between the ends of the rings. When compressed into the cylinder, that gap narrows down t 0.004", and that spring force is what keeps the ring tight against the cylinder sides.

[Johnmcc69]

 
 Nice work Brian!

 John

[Brian Rupnow]

After more trials and tribulations than you want to hear about, this is my 7/8" horizontal engine running with cast iron rings. This was much more of a struggle than I anticipated, but the fault was mostly that the grub screws holding the bottom timing gear had slipped enough that the engine was out of "correct valve timing".  To me, this is wonderful. This is the first 7/8" bore engine that I have installed cast iron rings in. In this video my engine is running on Coleman fuel.---Brian
<a href="https://www.youtube.com/watch?v=WifDJa8tBZ4" target="_blank">http://www.youtube.com/watch?v=WifDJa8tBZ4</a>

[Brian Rupnow]

Today I'm going to call this engine "finished". It is doing everything I set out to accomplish, and is running with cast iron rings. There is a bit of a write up with the video. Thank you all for watching the build and for the helpful hints and suggestions. ---Brian
<a href="https://www.youtube.com/watch?v=2j1gQ2O3dDs" target="_blank">http://www.youtube.com/watch?v=2j1gQ2O3dDs</a>

[crueby]

Lots of work, but a wonderful result!!

[Admiral_dk]

Great final result Brian 

[Kim]

Very nice, Brian! 
Kim

[Art K]

Brian,
Good to see you have a runner!
Art

[Brian Rupnow]

This video, made 17-Feb 2022 shows my most recently designed and built single cylinder horizontal engine running with a home made sparkplug. I had issues with the cylinder head, mainly because I messed up the  1/4"-32 threads for a standard sparkplug, so had to redrill and tap to a 5/16" fine thread. I had Steve Huck make me a "special" sparkplug with a 5/16" fine thread, but could never get it to work consistently. Then I made a sparkplug, but my design was a bit fishy, with a 0.060" spark gap. It would spark to get the engine running, but as soon as it warmed up, the spark would jump across the outside of the sparkplug to ground and the engine would stall. Finally, a redesign of the sparkplug with an 0.025" spark gap worked successfully, and the fact that the sparkplug is 3/8" longer than the first home made sparkplug keeps it from arcing to ground on the outside of the sparkplug. I am happy, the engine runs fine, and now I can put this project to bed. If you want to buy a complete set of plans to build this engine, contact me at brianrupnow@gmail.com---Brian <a href="https://www.youtube.com/watch?v=gTnwDFAI-MU" target="_blank">http://www.youtube.com/watch?v=gTnwDFAI-MU</a>