Upshur's twin opposed cyl. engine

[Brian Rupnow]

Today I cut cylinder head fins and made up a couple of rocker arm support towers. Not terribly exciting, but it took up most of my day. There is something a little fishy about the bearing support tower in the drawing package from Upshur. Haven't quite figured out what it is yet, but there is something about the #5-40 threaded holes tapped in the rocker arm support towers and in the head.

[Jasonb]

I see two little fishies

1. The thread into the head is quite shallow so you need to make sure you avoid the spark plug thread and also don't overtighten things and strip the shallow thread.

2. If the rocker post is also threaded as shown you may find it hard to get things to line up

[GordonL]

Today I cut cylinder head fins and made up a couple of rocker arm support towers. Not terribly exciting, but it took up most of my day. There is something a little fishy about the bearing support tower in the drawing package from Upshur. Haven't quite figured out what it is yet, but there is something about the #5-40 threaded holes tapped in the rocker arm support towers and in the head.

See note #9 on the Upshur drawing. The rocker arm support is not drilled through. It is fastened with a threaded stem locktited in place.

[Jasonb]

Funny enough I suggested that over on HMEM, Would I had not seen the note

https://www.homemodelenginemachinist.com/threads/upshurs-opposed-twin-engine.36037/post-410481

Is that note on the original Upsure drawings as I  can't see it on the MEB ones? They also show it with a single cap head screw through the whole lot.

[Roger B]

I understand that many people have successfully built Upshur's engines but that does seem a somewhat dubious design with the spark plug recessed at the end of a small hole and the limited engagement of the rocker tower holding bolt. A stud and nut would be a better solution.

[Brian Rupnow]

Today I broke out my gear cutting stuff, and made gears for the Upshur. These gears actually fit inside the crankcase, but I stuck them on the outside just to be sure that they meshed properly and to take the picture. I haven't had lunch yet and it's 3:52 here, so I'm up up and away to eat something!!!

[Art K]

Brian,
Maybe the twin is different, but my Upshur vertical single has a drilled hole. The post is square on top turned on the bottom. The head opposite the spark plug has a set screw to hold it in place
Art

[Jasonb]

The twin is different as the sparkplug goes where the single has the grub screw due to wanting to keep the spark plug high to avoid problems if the engine floods

[Brian Rupnow]

No machining over the weekend. This weekend was devoted to leaf raking. My one acre lot is surrounded on 2 sides by oak and maple trees, and I have an awesome amount of dead leaves to get rid of every spring. With the help of two grandchildren and good wife we raked up 33 bags of leaves and got them out to the curb for pick-up. Every spring I breathe a sigh of relief when that job is finished.--Now, on with my build.

[Brian Rupnow]

This morning was devoted to tappets and tappet guides. The tappets are as per Upshur drawings. I added a 0.050 thick flange to the end of the tappet guides. The guides are pressed and Loctited to the crankcase plates.

[Kim]

No machining over the weekend. This weekend was devoted to leaf raking. My one acre lot is surrounded on 2 sides by oak and maple trees, and I have an awesome amount of dead leaves to get rid of every spring. With the help of two grandchildren and good wife we raked up 33 bags of leaves and got them out to the curb for pick-up. Every spring I breathe a sigh of relief when that job is finished.--Now, on with my build.

Glad you got all your leaves picked up!  Around here, fall tends to be the time of year people pick up their leaves.  But maybe it's different up north where it's so cold in the fall!

Kim

[crueby]

No machining over the weekend. This weekend was devoted to leaf raking. My one acre lot is surrounded on 2 sides by oak and maple trees, and I have an awesome amount of dead leaves to get rid of every spring. With the help of two grandchildren and good wife we raked up 33 bags of leaves and got them out to the curb for pick-up. Every spring I breathe a sigh of relief when that job is finished.--Now, on with my build.

Glad you got all your leaves picked up!  Around here, fall tends to be the time of year people pick up their leaves.  But maybe it's different up north where it's so cold in the fall!

Kim

Its not being farther north, its the type of tree. Many of the oak trees have leaves that turn brown but stay on the tree over the winter, and they fall in the spring. Some other trees that drop in the spring are Hickory, Holly, Southern Magnolia. Most maple trees turn color and fall off in the fall as you are used to unless there is another issue like fungus on the tree.

[Kim]

Well, that's fascinating!  The things I never knew!  I thought all deciduous trees lost their leaves in the fall.  Guess that's what you get for living in the same part of the country your whole life, eh?

And to keep Brian's build log on topic, I just want to say, your engine is looking good! 
You are quite prolific and make a lot of engines very quickly!  Much faster production than I have!

Kim

[Brian Rupnow]

Today has been a laid back kind of day. I made the oil filler tube and Loctited it into place, made the oil filler cap and right now it is mounted on a short piece of 3/8" shaft so I can cross drill it. I also made up the distributor ignition adapter plate and made up both exhaust pipes. That's not a lot, but somehow it has filled up most of my day.