Upshur's twin opposed cyl. engine

[Brian Rupnow]

As work on my inline twin engine comes to an end, (and no, it isn't running yet) I've been feeling the urge to design something.  Last week I purchased the plans to "Upshur's opposed twin engine". The drawing package is really well done, and is in 2D format. One of the big pluses about this engine is that it runs a distributor cap and rotor, something I have wanted to know more about. I have redone the plans in 3D format to familiarize myself with all of the components, and it really is a sweet looking engine. I won't be selling the plans to this engine, but it should make for a very interesting build. Andrew Whale of the U.K. just happens to be building this same engine currently.  I will follow the plans for this engine---to a point. I may use a purchased set of ignition points instead of the spring brass with tungsten points soldered to it, which is used in the original plans.  Stay tuned, as after I get my inline twin engine running, this will be my next build.----Brian

[Art K]

Brian,
One of the engines I brought along when I stopped in for a visit was built from the plans for Upshur's vertical single. You should have fun building this one!
Art

[Brian Rupnow]

Hi Art---It's nice to hear from you. I'm building this engine "on the cheap". I have found enough material laying around in my shop to make the bottom plate, front plate, rear plate, cylinders and cylinder fins. The plans call for 0.156" machinists tooling plate for the sideplates, as they have to be silver soldered to the cylinders. I don't have any of that, but I think I have a way to substitute something else. I roughed out the plates on the bandsaw, and this afternoon I hope to machine them to finished size and put in any tapped holes and threaded holes.

[Brian Rupnow]

Now, this makes me very happy!! I machined the cylinders from cold rolled steel and machined what will become the fins from aluminum, both exactly as per the plans. The interface between the cylinders and the sleeves is a "heat shrink" fit. I machined the hole in the aluminum .003" less in diameter than the outside of the steel sleeve. Then set the aluminum in my heat treat furnace for half an hour, then used my vice and a big hammer to seat the steel sleeves into the aluminum. All went well. I have been told by someone else who is building this engine that it is much better to assemble the aluminum fin section to the steel cylinder before you cut the fins. There are always "score" marks from the assembly on the aluminum sleeves (It's kind of a brutal operation) and these marks can be machined away when the fins are cut.

[Brian Rupnow]

 I got up bright and early this morning and machined the fins into the aluminum on the cylinders. It went very well. A bit of butt clenching plunge cutting to 0.188" to make the fins, but lots of cutting oil and fairly low speeds got the job done.  Now I have to call and order some ball bearings and sparkplugs.

[Brian Rupnow]

Worked hard all day and didn't get much done!!---Some days are like that. I went across town today and bought some material---If you need any 5/16" drill rod, don't come to Canada to buy it. 36$ for a three foot length of it. I completely finished the baseplate, and half finished the front and rear plates today. I had enough 1/4" steel plate to make the front and rear plates from, but considering the price of #4-40 taps versus the cost of a bit of aluminum flatbar, I decided that it would be smarter to buy the aluminum. Tomorrow I'm off to a steam show with a friend of mine.

[Brian Rupnow]

Just got back from the steam museum at Puslinch, Ontario. A friend who I had done some machining for took me down for a tour. Many amazing large machines from a different era, very impressive to see. It was nice to get away from home for a day and do something different.

[Brian Rupnow]

Does anybody know where to buy 1/4"-32 sparkplugs in Ontario, Canada? I like the Rimfire VR2 series sparkplug and I'd like to buy a pair of sparkplug boots as well.---Brian

[Brian Rupnow]

After what seemed like an awful lot of drilling and tapping, I was able to assemble the crankcase body and "pose" the two cylinder assemblies in it. They are not soldered yet. ---I have to go across town and pick up some ball bearings and try to hunt down the silver solder that the plans call for.

[Jasonb]

Should not be too hard to find as it is the common mix for "Lead Free" soft solder 4% Silver and 96% Tin

[Brian Rupnow]

I checked thru one of my boxes of "Keep forever chit" and found three 1/4-32 sparkplugs. Good on me. I picked up my ball bearings for the crankshaft, fitted them with a piece of the 5/16" drill rod thru both bearings , and Loctited them into the crankshaft plates.--Also found a store that sells the special blend of silver solder that is called out in the plans, along with a small bottle of flux and an application brush. Tomorrow I will attempt to silver solder the cylinders to the appropriate crankcase plates.

[Brian Rupnow]

So--Today I built a crankshaft. I crazy glued the three plate sections together before drilling and reaming, but as is my usual luck with crazy glue, they came apart while in the vice being drilled. I was able to make a save however, and things worked out okay. Right now everything is in place, and I will wait 24 hours for the Loctite 638 to set up good before I drill and pin them. After the drilling and pinning is finished, I will cut out the pieces of the main crankshaft from between the webs.

[Brian Rupnow]

 I didn't like that one crankshaft web, that got kind of mangled when the crazy glue came unstuck, so this morning I replaced it.
The bad crank web is out, the new crank web is in. All went well, now to decide if I'm going for pistons next or for con rods.

[michaelr]

Brian you seem to be getting off to a good start on the Upshur twin, but you did say (Quote  Stay tuned, as after I get my inline twin engine running, this will be my next build.----Brian )

I was looking forward to seeing the Inline Twin running, so did you get the engine running.

Mike.

[Brian Rupnow]

Michaelr--Nope. haven't taken any time out to play with the inline twin. I will go back to it after I complete this new engine. Sometimes when engines won't run, the best thing you can do is to just walk away from them for a while. So, my main work today was to make a couple of pretty pistons. All turned out well, I used up some more "shorts" out of my "extra material bin". There are a lot of set ups to making pistons. Nothing scary, just a lot of set ups. Good wife has just appeared and given me a list of things to do, so that's it for today.

.