Author Topic: Upshur Horizontal Farm Engine - Mike's Version  (Read 4728 times)

Online mikehinz

  • Full Member
  • ****
  • Posts: 294
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #45 on: October 22, 2021, 11:07:06 PM »
I'm now down to the last major item to build for this engine:  the carburetor.  I spent a considerable amount of time trying to learn the basics of carburetion for small model engines and what the alternatives are.  In the end, I decided to attempt to build the carb first documented by Chuck Fellows, with well documented builds by Brian Rupnow and Andrew Wakefield and I'm sure others as well.  I liked this carb as it seemed relatively simple to build and it offers a throttle option.  I did end up building a 3d CAD model of this carb for my version of this engine and generated 2d drawing which I used to build the engine. 

So to start I milled a small piece of Al to the required dimensions for the body of the carb and then spotted the off-center hole on the body using the mill.  I drilled a small center hole at the spec'd location and moved to the lathe.



On the lathe, I put my spring loaded centering rod in the tail stock and then used a dial indicator to center the rod which in turn puts the to be drilled hole in the correct location.  As you can see, I used my 4J chuck and had to use some thicker packing under the jaws in order to actually grip the material.  My 4J is an 8" model and that's really too big for this sort of work, but I did manage it.  One of these days I'd like to get a 4" or 5' 4J for work like this. 



Then drilling thru at the just located point.



Then turning down the OD to round.  This is on the intake end of the carb.



Then, I changed the 4J back to the collet setup and turning down the outlet end to .25"



Threading the outlet side 1/4-32 with my tailstock mounted die holder.  Rather than using a slip fit and Loctite, I decided to thread all the ports on the head the same as the spark plug since I have the 1/4-32 tap and die on hand.  On the Webster I build, I noticed that the Loctite wouldn't necessarily hold well when the head got hot. 



Next I moved back to the mill and drilled thru the body as called out on the drawings and also tapped 10-32 in what will become the throttle hole.  Here's the body with the work completed on it as compared with the print.



Next part to be made was the jet.  I started with a piece of 3/8" hex brass stock and turned the first end down and then drilled .052" to start forming the jet.  I was careful as this hole has to be drilled to .625" so i was careful to clear the chips often while drilling.  Shown is the drilling operation with a 20P coin for size comparison.



Threading 8-32 on the longer end of the jet.  This was done with my tail stock die holder and rotating the holder by hand. 



Back over the mill with the jet held in a collet block.  After finding center of the block and the end of the part, shown is drilling a .040" hole thru the side of the jet, being careful NOT to drill into the other side of the ID.  The Queen is observing the operation. 



Back to the lathe, holding the part in a collet by the just finished end and  turning down the opposite end to .125" OD.  This is what becomes the fuel input port.



After drilling the initial .063" hole, shown is shown drilling thru the remaining material in the jet with an .040" drill.  The 20P coin is there for size comparison.



And here's the jet after it was finished laid on the drawing.



The next part to be built is the needle assembly.  The first problem I ran into was that I had no idea what a '#18 darning needle' was.  So I went over to a local sewing store and ask the question.  They came up with 2 items, both packages only about $2 so I bought them both, just in case.  On the left is what is known as a '#18 chenille needle' and on the right is a '#18 darning needle'.  It turns out they are both the same diameter that being .049" to .050" and the #18 refers to AWG.  As you can see the differences are the overall length and the eye, but either works fine to make a carb needle from.  Hopefully this info helps someone out!



Shown is how the needle fits within the jet.  It seemed like it fit properly so I decided to proceed with what I had.



I knurled a short piece of 3/8" brass just to give the needle adjuster just a bit of grip.



Next was turning down the small end to .22" and parting off the adjuster.



I didn't show the lathe operations, but they were pretty simple, just drilling and tapping from one side, then turning the part around and drilling thru for the needle.  Shown is the finished part on the print, and you can see where I needed to hand-correct a mistake I made when doing the CAD model. 



Here's the needle after cutting it to length, ready to be soldering into the adjuster.  I used Harris lead-free plumber's solder.  This is the stuff with 4% silver content that melts at a low temp, typically about 430F or so.  I find it quite easy to work with.  I also used the matching Harris flux.  The needle is gently inserted as deep as it can go into the jet and the adjuster is backed out about 2 full turn.  Both parts had flux applied and a very small piece of solder was laid right in the center of the adjuster where the needle passes thru it.  I made a very small countersink on the hole in order to give a place for the solder to flow to.  A small plumber's torch was used to apply heat.



And finally here's the finished carb on top of a 123 block.  I ended up NOT using the slits on the adjuster to apply tension, but made an additional spring to apply tension to it.  The issue I had when I tried to use the slits for tension is that they simply didn't' work all that smoothly and tended to bind at different point on the thread.  I made both of the springs from .022" music wire using one of my spring winding mandrels.  I have enough experience making springs now that I find it fairly easy.



So now all the major parts are finished!  Nothing left to do but to do the final assembly and then try to start it up!

All for now.

Enjoy!

Mike
MIke
Wichita, KS, USA

Offline RReid

  • Full Member
  • ****
  • Posts: 826
  • Northern California
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #46 on: October 23, 2021, 02:26:34 PM »
Quote
Nothing left to do but to do the final assembly and then try to start it up!
Great Mike! Looking forward to your first pop! :ThumbsUp:
Regards,
Ron

Offline Admiral_dk

  • Full Member
  • *****
  • Posts: 2724
  • Søften - Denmark
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #47 on: October 23, 2021, 07:47:12 PM »
Me too ...!

Offline ART

  • Full Member
  • ****
  • Posts: 34
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #48 on: October 23, 2021, 10:16:56 PM »
Hello Mike, I have enjoyed watching your build of this engine, as I have built several of them, one of which I have posted on my You Tube channel. I, also, made several changes similar to yours, and had the pleasure to have exhibited with Mr. Upshur for a few years where I talked with him about his designs. He deliberately designed these engines to be slow runners with a compression ratio of about 5:1 hence the .312 clearance at TDC. I noticed your flywheels are a little larger than designed. This may contribute to a slow running engine also. My flywheels are bronze and machined to the design. They each have a mass of around 17.5 oz., and my engines run about 350 - 400 RPM. I hope you have it running soon.
Earl

Offline 90LX_Notch

  • Full Member
  • ****
  • Posts: 1591
  • North Eastern Pennsylvania USA
    • YouTube Channel
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #49 on: October 23, 2021, 10:18:09 PM »
Eagerly awaiting the video of it running Mike.

-Bob
Proud Member of MEM

My Engine Videos on YouTube-
http://www.youtube.com/user/Notch90usa/videos

Online mikehinz

  • Full Member
  • ****
  • Posts: 294
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #50 on: October 25, 2021, 12:03:46 AM »
Gents, thanks very much for following along with this build.  Just for reference my flywheels are from Martin Model and ended up 4 1/8" OD and weight about 19 oz each.  Hopefully using these flywheels was a good decision and I'll end up with a running engine!

Mike.
MIke
Wichita, KS, USA

Online mikehinz

  • Full Member
  • ****
  • Posts: 294
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #51 on: October 25, 2021, 12:48:29 AM »
This post will cover the final assembly of the engine. 

I tore the cylinder off and installed a viton o-ring on the piston and then reassembled the cylinder to the frame.  I knew I had interference between the rocker arm post and the 6-32 nuts, so I made some model scale nuts and washers.  This took a bit too much time as I had to make a bit of hex stock out of round as I didn't have the correct hex stock on hand.  But in the end, here's what I ended up with as compared to the standard 6-32 nuts and washers.  The model scale fasteners are smaller in diameter but are considerably taller than the standard fasteners.



Here the head is refitted to the cylinder with the new model scale fasteners.  They fit correctly and looked good to my eye.



Here's the head fully assembled on the engine.  I spent a considerable amount of time making sure that there was no binding anywhere in the valve train.  I also modified the rock arm just a bit, filing and grinding a better radius on the bit that touches the top of the exhaust valve so its action was as smooth as possible.



Here I have the engine on my welding table, secured temporarily to a scrap bit of 2x4 lumber using some very crude toe clamps that allowed me to screw it to the 2x4 with a couple of deck screws.  You can also see the spark plug is removed and is clip leaded to the S/S ignition system.  I wanted to make sure that I had proper spark and I also set the timing to be right at or slightly before TDC.   The LED timing light on the S/S ignition module makes timing very easy to set. 



Here's the S/S ignition system all rigged up and ready to go.  I'm using some rechargeable NiMH AA batteries and the seems to last a long time when running the engine. 



And as they say, 'that's that!'  Nothing left to do but try to start it up.  So after a bit of time spent varying ignition and exhaust timing all over the place with no joy, I noted that I couldn't see any movement on the intake valve nor could I hear that 'snorting' sound that some describe.  So I thought that the intake valve spring might be too strong.  So after quite an adventure of removing the existing spring, losing somewhere on the shop floor and making a new one and shortening it by 1 coil, I got this to occur:

<a href="https://www.youtube.com/watch?v=5_hhxoa1hRo" target="_blank">http://www.youtube.com/watch?v=5_hhxoa1hRo</a>

I then played with the carb setting quite a bit and managed to get another run with the carb throttle set to run about as slow as I could manage to get it to run.

<a href="https://www.youtube.com/watch?v=XDS8Rb1_fNA" target="_blank">http://www.youtube.com/watch?v=XDS8Rb1_fNA</a>

Notice that I'm just using a fuel tank from a hobby R/C plane for now.  The fuel I'm using is some Echo brand 50:1 pre-mixed gasoline.  This is the stuff that comes in a 1 liter container and is said to be ethanol free.  I also noticed that the carb is quite sensitive to the needle adjuster position and it seems to need adjustment as the engine warms up and as I varied the rpm.  I think I had it open only about 1/4 turn when the engine was warm. 

That's it for now!!  I'm now starting to work on the hit-n-miss parts and will post the progress of that work as it occurs and hopefully will have a better video of the engine running in h-n-m mode!  I also will make a better wooden base and put some sort of a plaque on the base.

Enjoy!

Mike
MIke
Wichita, KS, USA

Offline 90LX_Notch

  • Full Member
  • ****
  • Posts: 1591
  • North Eastern Pennsylvania USA
    • YouTube Channel
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #52 on: October 25, 2021, 03:17:14 AM »
Mike-

Nice! Congratulations, it is always a great feeling when they come to life. Well done.

-Bob
Proud Member of MEM

My Engine Videos on YouTube-
http://www.youtube.com/user/Notch90usa/videos

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 5525
  • Portland, Oregon, USA
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #53 on: October 25, 2021, 06:27:59 AM »
Excellent!  She runs!  :ThumbsUp:

And your cute little carb seems to work just great!

Kim

Offline Admiral_dk

  • Full Member
  • *****
  • Posts: 2724
  • Søften - Denmark
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #54 on: October 25, 2021, 10:13:19 AM »
Sounds and runs fine - you should be happy with the result  :cheers:

Offline MJM460

  • Full Member
  • ****
  • Posts: 1513
  • Melbourne, Australia
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #55 on: October 25, 2021, 11:35:55 AM »
Well done, Mike.  A great result.

MJM460

The more I learn, the more I find that I still have to learn!

Offline RReid

  • Full Member
  • ****
  • Posts: 826
  • Northern California
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #56 on: October 25, 2021, 01:51:18 PM »
Congratulations Mike! Excellent work all around. :ThumbsUp: :cheers:
Regards,
Ron

Offline ART

  • Full Member
  • ****
  • Posts: 34
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #57 on: October 25, 2021, 03:22:44 PM »
Congratulations on a sweet running engine.  Earl

Offline sid pileski

  • Full Member
  • ****
  • Posts: 136
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #58 on: October 25, 2021, 04:51:11 PM »
Very nice and congratulations!
I love that your flywheels don't wobble! I personally hate that.
Are you going to enclose the SS ignition in the model, or have it to share on other engines?

I've included one ignition to an engine. That can get expensive, but makes for a cleaner looking build in the long run.
Also, I've used rechargeable batts with a charging port so that I don't have to tear the base apart to change batteries.

Sid

Offline Don1966

  • Full Member
  • *****
  • Posts: 6630
  • Columbia, MS
Re: Upshur Horizontal Farm Engine - Mike's Version
« Reply #59 on: October 26, 2021, 12:12:43 AM »
What a cutie little engine and runs a treat. Awesome results Mike and ………..I…………likeeeeeeee….  :Love:



 :cheers:
Don