Author Topic: Rebuild time for my Upshur single  (Read 6902 times)

Offline Art K

  • Full Member
  • ****
  • Posts: 1761
  • Madison, Wisconsin USA
Rebuild time for my Upshur single
« on: March 02, 2020, 01:55:48 AM »
Hi all,
I have been working out in the shop a bit lately. Towards the end of last summer I decided it was time to pull my Hamilton Upshur based vertical single apart and figure out why it was running so bad. This is what I found.


You can see in the first photo the spots on the rod where it was hitting the cylinder & cam. On the cylinder you can see the contact point, there's a matching one on the top side you cant see in the photo. On the crank the rod throw is .003 under on the high points so a new crank is also in order. In the bottom photo you can see the .040" oblong. No fix but a new one there as well. I have made a start on some of this and will post my progress as I am able. I have a link to the other forum that I posted soon after joining there.
https://www.homemodelenginemachinist.com/threads/my-first-engine.18599/
I have made a lot of changes over the years, all have made it better or solve self inflicted problems.
Art
« Last Edit: March 08, 2020, 03:55:50 AM by Art K »
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline kuhncw

  • Full Member
  • ****
  • Posts: 232
Re: Rebuild time for my Upshur single
« Reply #1 on: March 02, 2020, 09:15:06 PM »
Hi Art,

Which grade of aluminum did you use for your original connecting rod?

Chuck

Offline Art K

  • Full Member
  • ****
  • Posts: 1761
  • Madison, Wisconsin USA
Re: Rebuild time for my Upshur single
« Reply #2 on: March 02, 2020, 09:48:39 PM »
Chuck I think it was probably 6061 t5. But I also bored it over size & filed the cap down to compensate.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7575
  • Barrie, Ontario Canada
Re: Rebuild time for my Upshur single
« Reply #3 on: March 03, 2020, 01:12:05 AM »
Art was up to Canada last summer, and stopped by for a visit. He had brought a couple of his engines with him, and ran them for me. Very nice little engines. I think the engine featured here was one of them.--Brian

Offline Art K

  • Full Member
  • ****
  • Posts: 1761
  • Madison, Wisconsin USA
Re: Rebuild time for my Upshur single
« Reply #4 on: March 03, 2020, 03:31:47 AM »
Brian,
Yes this was one of the engines I brought along last summer. Soon after getting home I started to dismantle it. I turned a blank on on the lathe to make a new cylinder head. I left the diameter and the top oversize, then left the .040" on top to give the valve guides a little extra. The bottom looks like this. The top despite being stranded in the chuck in the rotary table for 5 months I never got a photo of.

When I got my Tormach it came with a Dell PC. When I switched to Path Pilot I couldn't use that PC any more. I had a used computer built at 1/7 the price of the Tormach unit. Well in August or September the power supply blew taking the mother board with it. My computer guy had one to replace it but couldn't set it up properly (or understand why I'd want it set up that way). On top of that he was out due to surgery, had a hard time getting caught up with it. In the end I drove 3 hours dropped it off for my nephew to look at and took it home with me 3hours later, two weeks before Christmas.
I used the 4 holes on the bottom surface with screws cut off to locate it and bolted it down through the valve guide holes.

This is what it looked like after the roughing pass.
Art
« Last Edit: March 08, 2020, 04:00:17 AM by Art K »
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Art K

  • Full Member
  • ****
  • Posts: 1761
  • Madison, Wisconsin USA
Re: Rebuild time for my Upshur single
« Reply #5 on: March 04, 2020, 02:10:52 AM »
The next thing I did was to switch to the "high speed spindle" and machine the cooling fins. This is the end result.


This job took 5 and a half hours...just kidding but I did do a dry run so I did sit and watch the machine for that long. I used a .047" end mill and cut to a depth of .362" 20,000rpm@35 IPM and .0015" per pass. Theoretically Sprutcam thought it should have taken 30 minutes less, but didn't take into account the time it took to slow down going around radius & corners.
I will slowly post what I have done and get you all caught up. I am still pondering how much I want to do, for example I think the rod hitting the cam specifically damaged the exhaust valve but do I want to replace that now or later. I think time will tell as I intend to have it running for the NAMES show.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline awake

  • Full Member
  • ****
  • Posts: 303
Re: Rebuild time for my Upshur single
« Reply #6 on: March 04, 2020, 09:16:22 PM »
Beautiful!

Sent from my Lenovo TB-8504F using Tapatalk

Andy

Offline Art K

  • Full Member
  • ****
  • Posts: 1761
  • Madison, Wisconsin USA
Re: Rebuild time for my Upshur single
« Reply #7 on: March 05, 2020, 01:27:48 AM »
Andy,
Thanks for following along, it's good to know that people are keeping track of what I'm working on. I have made a few other parts like tappets & guides as well as manifolds that I can press into the head and bolt the carb & muffler onto.

These are the lifters and guides. I am planning to redo the lifters because I put divots in them when I chucked them on the second side to face them to length.

This is the family photo so to speak. With the new & old head side by side. I am missing a photo so I will have to add one later. The aluminum bits are the press fit manifolds that I've done the oval treatment to and drilled & tapped 2-56. this now gives me a platform to bolt on anything on that I can make an attachment for. previously to remove the carb, manifold ect. I had to twist it out with a pliers.

This is what it looked like at the 2019 NAMES show. I've had the intake straight out 90 degrees down as designed and as shown in the photo. I only set it up this way cause I didn't like it spitting gas under the carb. More later, please if you have any questions, ask.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline AlexS

  • Full Member
  • ****
  • Posts: 269
Re: Rebuild time for my Upshur single
« Reply #8 on: March 07, 2020, 07:37:48 PM »
Great job of your start on rebuild this engine! May I ask how your build en designed the PCV on your crankcase? I have to build that for me engine soon. Are you redesign the conrod or cylinder so they don't hit each other? This engine is a full plan build or own design? I am wondering what reason is if it is a plan build.

Greets Alex Succes! :wine1:

Offline Art K

  • Full Member
  • ****
  • Posts: 1761
  • Madison, Wisconsin USA
Re: Rebuild time for my Upshur single
« Reply #9 on: March 08, 2020, 03:38:40 AM »
Alex,
If I understand what you are asking about the PCV, you are asking about the crankcase ventilation? If so that would be the round brass cap with holes in it. This is just behind the cylinder in the previous photo. It is where Hamilton Upshur designed it in a dry corner. Its just stainless tubing with one end pressed into the case & the other into the hollow brass breather which has green scrubby pad wrapped around the inside. I wasn't planning to change any of the internals. There was only a problem when the rod wore and then shifted a portion of the rod with a larger diameter upwards. There is clearance for the point where the rod is designed to pass, but not the larger diameter. I had thought about redesigning the rod but because of the restricted clearance inside opted to go as designed.
« Last Edit: March 08, 2020, 04:45:17 AM by Art K »
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Art K

  • Full Member
  • ****
  • Posts: 1761
  • Madison, Wisconsin USA
Re: Rebuild time for my Upshur single
« Reply #10 on: March 08, 2020, 04:43:00 AM »
Ok I had said I was missing some photo's earlier, so here they are. After doing the cooling fins I flipped the rotary table so the holes around the diameter could be done. Here are the manifolds pressed in as well.


Pressing the manifolds worked really well. I mounted the fixture in an angle plate lined up the holes with the 1/4 shank of an end mill then the manifolds with a 3/16 drill and pushed them in right on the drill press. The hardest part was trying to line up the 2-56 holes straight.
Then I moved on to the crank. I had a piece of 1144 so I cut and faced it to length. Mounted it in the v-block indicated it center drilled the two centers. Then flipped it and repeat. I was then able to use a lathe dog and turn the crank throw.

I used a standard cutoff tool to rough it out.

Then spent what seemed like forever on my wimpy grinder making a tool that could cut the rest of the groove. It started out as 1/4 X 3/4 I was concerned but it worked great, I needn't have worried. Today I spent spent turning the gear side of the shaft with it's three diameters .329 for  the gear .315 for the bearing and .3125 for the shaft.

Well I think this is enough for now.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Don1966

  • Full Member
  • *****
  • Posts: 6817
  • Columbia, MS
Re: Rebuild time for my Upshur single
« Reply #11 on: March 08, 2020, 08:12:07 PM »
That looks great Art!!....


 :cheers:
Don

Offline AlexS

  • Full Member
  • ****
  • Posts: 269
Re: Rebuild time for my Upshur single
« Reply #12 on: March 08, 2020, 08:14:03 PM »
Thanks for reply Art!

Offline Art K

  • Full Member
  • ****
  • Posts: 1761
  • Madison, Wisconsin USA
Re: Rebuild time for my Upshur single
« Reply #13 on: March 09, 2020, 12:28:33 AM »
Don,
Thanks it's great that people are following along.
Alex,
I hope that my info was helpful. I originally didn't want it there, thought it would clutter the cover. I now have a nice oil filler plug in my first choice. Think about rotation of the engine, where splash lubes will push the oil. Right where I put it. :wallbang:
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7575
  • Barrie, Ontario Canada
Re: Rebuild time for my Upshur single
« Reply #14 on: March 09, 2020, 12:44:51 AM »
Okay---I have to ask---What is holding the hex nut in place between the cheeks of the crankshaft? I don't see any glue (I use a hot melt glue gun). Sure hope you didn't just wedge it in there.---Brian

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal