An Upshur Farm Engine (slight return)

[chuck foster]

i keep reading these posts and my head hurts.............i think  ALL the neat little tricks you guys are showing. they are stretching my brain to the limit 

example: i would have NEVER thought of making one piece valves they way you did tim.
that cutter is just the greatest idea. i have always made 2 piece valves (silver solder the head to the stem)
or one piece, but i took lite cuts till i got down to the right stem size.

i must stop reading these posts............................yeah right, i will be reading all i can 

chuck

[tvoght]

Thanks for watching Chuck.

Here's some simple stuff to get things started on the fresh posts.

The upper and lower pushrod guides are made of brass.

The lower guide screws to the side of the frame just ahead of the cam.
It's a real straightforward piece, and I'm not showing the machining steps.
Here it is finished.



The upper guide clamps under a nut on one of the cylinder studs and is
.032 brass. I scratched around on a shelf where I keep little scraps that
ordinary people would throw away and found a .062 thick piece of brass that
had been previously thinned down from 3/16 stock for another project. I
clamped it down on a sacrificial tool plate and thinned a section down to
.031. I milled across the free end to establish a DRO reference, and then
drilled the two necessary holes. Then I milled down through the side outlines
(photo) and then across the top to separate it. The remainder went back on the
scrap shelf!



One end was to be rounded. I hung the piece on a drill bit over the
mill vise jaws and and clamped it. I located my end mill from the drill bit
shank, and then clamped the piece in a few positions to mill facets and form
the radius.



Here is the piece before I file the facets down to complete the part.



Thanks to everyone looking.
--Tim

[Bearcar1]

Some really nice work Tim. Thanks for sharing it. I am likin' it very much.

BC1
Jim

[Dean W]

Nice work, and again, great job showing it.  I've cut quite a few valves, but I'll keep your valve cutting jig in mind
for the next time.  That's a good trick!

[cfellows]

Lots of great pictures, Tim.  And the work is first rate.  I've always loved the Upshur engines for their simplicity and elegant lines. 

Chuck

[tvoght]

Jim, Dean, and Chuck: Thanks for your comments. I'm glad you all looked.

A few posts back I showed how I intended to make a valve leakage fixture to
screw the head onto and apply pressure into the combustion chamber.

To further that idea, I made a plug to screw into the spark plug hole. I
have a spark plug I could have screwed in there, but I felt better about using
this plug. I threaded it on the lathe, which is still not something I'm very
good at, but practice, practice, practice. I cut flats on it for tightening.
 


I lapped the valves with toothpaste. As I had heard recommended by gbritnell,
I put the stems in a small drill chuck which gave me a good handle, and I could
use the weight of the chuck to provdide a steady pressure as I rotated back
and forth, sometimes lifting up off the seat a little to distribute the
compound. I have no meaningful pictures of that operation.

I printed out outlines for head gaskets and clamped the printout over a
piece of .010 teflon film (which you can't see here), and that over a cutting mat; then used an x-acto
knife to cut out a couple of gaskets. The small circles are gaskets for the
spark-plug hole plug shown above.



Here's the head on the leakage fixture with gaskets and plug in place. A
hole for the rocker arm post goes all the way through the head, but it's
plugged from the inside.



I submerged the fixture in water and blew on the hose as hard as I could.
Well, the fixture worked... I saw quite a few bubbles coming out of the
exhaust pipe hole. Heavy sigh. I lapped the exhaust valve some more, examining
the valve under magnification for a tell-tale dull gray band I had read about. I did see a band
on the intake valve that was not quite so pronounced or complete on the
exhaust valve. I lapped til the band looked similar on the two valves.

Back on the fixture and under water, and guess what? No matter how hard I blew
there were no bubbles.

I admit I don't know if breath pressure is enough to prove anything, but I'm
actually very hopeful. I'm kind of glad I got bubbles the first time so that I
had a point of comparison. I'm going to call the head done for now.

Thanks,
--Tim

[vcutajar]

Tim

Glad you used the testing fixture and put some photos of it.  Still need to lap my valves so that helped a lot.  I liked your idea of immersing it in water as it gives a better indication of leaks.

Vince

[steamer]

Nice build Tim....gotta get me a small tube of Colgate total!

Dave

[tvoght]

Vince, if you should try a similar trick, keep in mind that if water gets past the valve, it will no longer seat properly until it's carefully dried off.

Dave, the small tube of lapping compound was given to me by my dentist in lieu of a lollipop. Now how did he know I had a valve job coming up?

--Tim

[dsquire]

Vince, if you should try a similar trick, keep in mind that if water gets past the valve, it will no longer seat properly until it's carefully dried off.

Dave, the small tube of lapping compound was given to me by my dentist in lieu of a lollipop. Now how did he know I had a valve job coming up?

--Tim

Tim

Look what the lapping compound did to the valve. Imagine what prolonged use would do to your teeth.

You are doing some nice work there Tim. Thanks for letting us watch over your shoulder.

Cheers 

Don

[vcutajar]

Vince, if you should try a similar trick, keep in mind that if water gets past the valve, it will no longer seat properly until it's carefully dried off.

Thanks Tim.  I did not think of that.  Thanks for the heads up.

Vince

[ironman123]

This is kool.

Ray

[NickG]

Brilliant work Tim  Love I.C. engines, am in the process of designing a simple one that I could make ... whether I actually get around to making it is another matter!

[Russel]

Wow! Great work! I'll be following this thread, and learning. Darn it! Now I'm going to have to try making valves... Thank you for posting.

Russ

[Dean W]

Nice work, Tim.  Knowing that your valves seat well will save you a lot of messing around when it comes
time to crank her up.  One less thing to worry about!