1" Bore x 1" Stroke Vertical I.C.

[mnay]

Great job as usual.
I am following along here in North Salt Lake, Utah
The company I work for is owned by a Canadian Company called Westpower in Calgary.
Mike

[Brian Rupnow]

Hi Mike--glad to hear you are following. This morning I lapped the cylinder with a 1" expanding lap using 400 grit lapping paste (you can just see a corner of it in the foreground.) until it was about 1.002 finished diameter. I had turned the piston to 1.003" diameter yesterday, An expanding lap will always leave a small "bell mouth" at the end of the cylinder, and it can work to your advantage. Once the piston would just start to go into the cylinder end, I mounted the cylinder in my 3 jaw chuck on the lathe, and using a handle I had made up to hold the inside of the piston, coated the piston liberally with 600 grit compound and slowly worked it into the cylinder with the lathe running at about 50 rpm. Once it would pass completely thru the cylinder I stopped and cleaned everything up with laquer thinners. The piston to cylinder fit is perfect.

[Brian Rupnow]

Not a lot of machining done today, but some. I made up the fittings for the discharge end of the gas tank and got everything silver soldered or J.B. Welded together and cleaned up. Gas tank is now ready for paint.  Gas tank, gear case, flywheel and rocker arms will be painted, and maybe the cooling fan. I haven't thought much about a color yet, but it will be a Tremclad color. Laying on the desk behind the engine is a piece of 1144 stress-proof steel I picked up today to become a one piece crankshaft, and a length of 1/2" brass round rod to make miscellaneous bits and bobs from.

[Mike Bondarczuk]

This engine is really taking shape now and very well done on then home design 

Mike

[Brian Rupnow]

And at the closing of the day---We have two valve cages and two valves. The valves haven't been separated from their parent material yet, as I will use that for a "handle" when lapping the valves into their seats in the valve cages. The valve cages will get a hole thru the side, but won't be drilled until after they are Loctited into the cylinder head. That way I can drill the cylinder head and the valve cage at the same time. The cages will get the valve seat cut into them after they have been loctited into the head. In an earlier post I mentioned that I had picked up a weird size endmill. The maximum diameter of the valve cages is 0.375" diameter. They are sunk into a counterbore in the cylinder head. A   0.375" counterbore would have been too small, and a .438" counterbore would be too big. My "weird size" counterbore is 0.406" diameter, which should be "just right".(Makes me think of Goldilocks and the three bears).

[Brian Rupnow]

Today I used my odd size endmill and put the counterbores for the valve cages into the cylinder head. The cages were coated with #638 Loctite and then pushed into place. You can't really call it a press fit, because if it was a press fit the brass cages would collapse. It's more of a "perfect sliding fit". I will wait 24 hours for the Loctite to cure, then drill inlet and exhaust ports thru the cylinder head and the valve cages at the same time. Then I will lap the valves into the seats. I also made the timing adjustment handle today. I took a quick look thru all my available compression springs to see if any of them would work as valve springs, but I haven't made up my mind yet. Also made the adapter for the Traxxas carb but forgot to include it in the picture. I attached the gas tank into it's snazzy support using J.B. Weld. I'm running out of small things to make. Still have the cams and the crankshaft to machine. The cams and lifters will be made from 01 steel and flame hardened.

[Brian Rupnow]

Today seen the cylinder head drilled for intake and exhaust ports, and the muffler, carb adapter and carburetor mounted to the cylinder head. The oil filler tube was machined, along with the brass screw-on filler cap. I drove up north to see my 100 year old mother today, but she is fading badly. The nursing home is all locked down under Covid rules, and I had to get a test earlier in the week to confirm that I didn't have it.

[Art K]

Brian,
Glad to hear that you were able to see your mom, sorry to hear she's not doing well.
Art

[Brian Rupnow]

I'm doing a bit of assembly this morning, and these three shots are interesting. In the bottom of the main bearing cavity in this half of the gearcase, you will see the heads of four #6 flat head capscrews. They pass thru the gearcase and attach a steel ring on the outside of the gearcase. The plate with the handle on it is the plate to which the ignition points are attached. Screwing the handle in locks the points mounting plate in place. Unscrewing the handle half a turn lets me rotate that plate while the engine is running. Since the ignition points are attached to this plate, this lets me advance or retard the ignition timing while the engine is running.

[Brian Rupnow]

A shot of the other half of the gear case shows the oil filler tube pressed and Loctited into place.

[Brian Rupnow]

Elvis has not left the building---Elvis has struggled all day with cams and tappets.   I don't make cams often enough to have all the steps memorized. Basically, that means that every time I make a cam, I have to refer to a bunch of notes I have made and try to decipher what I actually meant when I wrote them. Here we have one cam, setting in place with a mushroom head tappet. Tomorrow I will make the second cam. Piece of cake, now that I have refreshed all my memories by making the first cam.

[Brian Rupnow]

And now we have two finished, hardened, oil quenched cams. That cam nearest the front looks a bit ragged on the edge, but it's not. The macro setting on my camera finds little flaws so small that they can't be seen by the naked eye. I have to go out to the hardware store and look at the paint color chart for Tremclad paint, and then it's almost crankshaft time.

[Brian Rupnow]

Uh-Oh--Something just happened. I was happily milling away a whole lot of 1144 stress-proof that wasn't going to be part of the crankshaft. Milling machine just stopped---lost all power. First I looked for the ratty little glass fuse that my old mill had, but this mill doesn't seem to have any separate little glass fuse. Next I checked the breaker in my electrical box.---It was okay. I don't know if the motor has a thermal overload cut out or not.---Doesn't have any visible reset button. Well, Poop!!! I didn't feel that much like working anyways, but I have to figure out what is happening with the mill before I can do any more.

[Admiral_dk]

Oh man  - that is really annoying .... and I hope not to expensive.

Best wishes

Per

[Craig DeShong]

Uh-Oh--Something just happened. I was happily milling away a whole lot of 1144 stress-proof that wasn't going to be part of the crankshaft. Milling machine just stopped---lost all power. First I looked for the ratty little glass fuse that my old mill had, but this mill doesn't seem to have any separate little glass fuse. Next I checked the breaker in my electrical box.---It was okay. I don't know if the motor has a thermal overload cut out or not.---Doesn't have any visible reset button. Well, Poop!!! I didn't feel that much like working anyways, but I have to figure out what is happening with the mill before I can do any more.

Well, BUMMERS!!!   hope it’s nothing serious.