An Upshur Farm Engine

[RReid]

Thank you, Per!

Are you going to try and match a similar paint job on the rest ?

I might do that, just on the outside surfaces of the frames. Unless I get lazy and don't. I often have ideas about painting the engines that I don't carry out because I don't like painting much!

Some years ago I used what was called "Hammertone" spray paint on the suspension parts I fabricated for a Lotus 7 replica I was building. The color would match that blue pretty well. The "hammered" texture was fairly subtle and looked rather nice, but while I can still find that paint, I've never been able to find that color again. Maybe I'll look once more.

[Admiral_dk]

I know the feeling about painting ....

Hamertone has been banned by the EU decades ago (nasty solvents / chemicals), so I haven't seen the 'Real Stuff' since my youth ....

[RReid]

One thing I enjoy at least as much as making parts from raw bar stock is re-purposing discarded “junk” into useful parts. Flywheels made from old cart/dolly/caster wheels are one example. A fuel tank made from an empty CO2 cartridge is another.

The cartridge was originally in a self-inflating PFD, or life vest. The rip cord wasn't pulled because I fell in, but only because I wanted to test the thing (honest!). That was 5 or six years ago, and the empty cartridge has been knocking around looking for work ever since.

I started by cutting off the end with the threaded nipple. A scrap bit of 12L14 was turned with a short step to fit into the now open bore, and drilled at the lower end for fuel delivery tube (a piece of 5/32 brass tubing). The top of the cartridge was drilled 3/8” near the opposite end to accept a filler neck. This is just a hardware store flanged bushing, also from the “left overs” drawer. Another bit of steel was turned to make a vented cap. This was heated to red and dunked in veggie oil for a "blacksmith's finish".

These various pieces were finally all soldered into place (except the cap), and a coat of grey primer/topcoat was applied.
An easy-peasy job to fill some time while I wait for the ignition coil I ordered to arrive.

[RReid]

I spent most of yesterday trying to start this thing, without much luck. Today though I made progress and finally got it running, although it still quits when it, rather than I, decides. There seems to be a very very fine line with the needle valve between not enough and too much fuel.

The "proof of operation" video below only captures about half of the actual run time, which was probably the longest so far. As I was getting ready to re-start it the exhaust valve spring retainer somehow slipped off the valve stem and went flying off to parts unknown, taking the valve spring with it. I have more springs, and can make another retainer easy enough, but AARRGGH!
<a href="https://www.youtube.com/watch?v=a1WdZz6iGbU" target="_blank">http://www.youtube.com/watch?v=a1WdZz6iGbU</a>

[Admiral_dk]

Great to see it run - always includes satisfaction when it happens

I do not know if it's a serious problem on an automatic inlet Valve - but looking at the video, it looks like quite a bit of gas is blown back out of the Carb ....

[Art K]

It is good to see your engine run. It doesn't surprise me that Upshur's carb is so finicky. I built and used his single jet on my single. It would spin 5-6k with that carb, but as you opened the throttle you also had to turn open the jet. Then reverse it as you slowed down.
Art

[RReid]

Thanks Per! I don't know if that blow-back through the carb is just due to the very light spring pressure required to allow the intake valve to work properly, or if the valve itself needs to be lapped in better. Maybe both. At least I know that it's not a show-stopper as far as getting the engine to run goes, but probably is important to getting it to run its best.

Thanks Art! I agree, the throttle and the needle valve do not operate independently. Any movement of the throttle lever also turns the needle valve, unless I hold onto it.

Anyway, today was frustrating. I could never get it to run like yesterday, just pops and snorts and a few short bursts. I need to practice Per's Danish swear words, then try again tomorrow.

[RReid]

I think I got it figured out. 

The ignition timing was too far retarded. Now it's running more or less as I would expect. And with it running I could tweek the needle valve to get the mixture about right without all the guesswork. I also got smart this morning and pre-heated the top of the engine with the heat gun (it was in the mid 30's F here), which helped too. And put in a fresh Viton piston ring for good measure. But the timing seemed to be the real key. Should have thought to try that sooner!
<a href="https://www.youtube.com/watch?v=aAV9NYiZNrQ" target="_blank">http://www.youtube.com/watch?v=aAV9NYiZNrQ</a>

[Hugh Currin]

I like the engine. And it looks like you have it sorted. Congratulations.

I also noted above you silver soldered some 12L14. I know you can't weld 12L14 but never thought about brazing it. I googled and, as you've shown, it can be done. Thanks for this info.

Thanks for sharing the build.

[RReid]

Thank you, Hugh!

Since they've now been demonstrated to work, I thought it might be useful to any future builders of this engine to post the few commercial components that I used.

Exhaust Valve Spring
McMaster-Carr Part #9657K651
Compression Spring, 0.625" Long, 0.240" OD, 0.204" ID
Wire Dia. 0.018”

Intake Valve Spring
McMaster-Carr Part #9657K644
Compression Spring, 0.625" Long, 0.180" OD, 0.152" ID
Wire Dia. 0.014”

Piston Ring (O-ring)
McMaster-Carr Part #8297T126
Hard Viton® Fluoroelastomer O-Ring, Chemical-Resistant, 1/16 Fractional Width, Dash Number 016

Spark Plug
#10-40
Steve's Miniature Spark Plugs
Steve Huck (www.miniaturesparkplugs.com)

The spark plug is a little beauty. Steve Huck is a very accomplished engine builder and a nice guy. I believe he's also a member of this forum.

[Admiral_dk]

Great result 

and simple solution 

[RReid]

Thank you, Per! I think it was invoking "SATANS osse !!! " that made the difference!

[Kim]

Congratulations, Ron!

The engine runs great, glad you got the timing figured out.  I had no doubt you'd get it running!

Kim

[Don1966]

Awesome…..


 
Don

[Admiral_dk]

I'm not sure that I would like to be known as the chap that spread the use of Danish profanity to the English speaking World .... but then again - that will most likely be Danish actors, TV shows, Movies etc. ....

That said - I'm glad it worked for you