1" Bore x 1" Stroke Vertical i.c. Engine

[Brian Rupnow]

So, there we have it. The design is essentially finished. My computer tells me that there are a total of 74 individual components, not counting fasteners. The two crank-case halves are designed to be cut from 3" x 1" aluminum flat bar. The base can be cut from a piece of 2" x 1" aluminum flat bar. I haven't included the poppet valve which screws into the crankcase to keep the crank-case in a semi vacuum condition (to avoid oil leaks around the bearings), because I'm not really sure that I need it. If I find out "after the fact" that I do need it, it can always be added later. The oil filler tube and cap have been added, as well as a drain plug in the very bottom. An "oil level check" hole and plug have been added to the side of the crankcase. You can see it just to the left of the outer gear case. You take out the plug and add oil in the filler tube until it starts to run out that hole. That hole is positioned so that when oil starts to run out of it, you know the oil level is correct. All of the tapped holes and clearance holes for fasteners have been added. The only thing I haven't totally decided on is how to attach the outer gear case to the crank case. If I make it from brass $$$, I can silver solder a couple of mounting tabs to it. If I cheap out and make it from aluminum, then it becomes a different story because I can't weld aluminum.

 

[awake]

Brian, one possible concern that occurred to me in the previous set of renderings - it looks like the fuel line from the tank to the carb may wind up rather close to the flywheel - ?

 

[Brian Rupnow]

I sent out a request for pricing this morning for material to make the two crank case pieces and the base from aluminum, enough brass to make the gas tank support, the rocker arm tower and the gearcase, and a piece of grey cast iron to make the cylinder from. I have scraps of material laying around here to make almost all of the remaining pieces. I have a section of heavy wall pipe sufficient to make the flywheel from, with a machined aluminum center.

 

[Brian Rupnow]

Awake--Many of the models used in this engine were imported from other older machine files. It just so happened that when I imported the gas tank assembly, the discharge spigot was as you see it.--Same as the inlet port on the carburetor. In reality I will be changing their position a bit to ensure that the fuel line is well clear of the flywheel.

 

[Brian Rupnow]

The aluminum bar for the crankcase and base was the easy part.---$30.

 

[awake]

Awake--Many of the models used in this engine were imported from other older machine files. It just so happened that when I imported the gas tank assembly, the discharge spigot was as you see it.--Same as the inlet port on the carburetor. In reality I will be changing their position a bit to ensure that the fuel line is well clear of the flywheel.

I wondered if that might be the case. Looking forward to seeing this take shape!

 

[Brian Rupnow]

Hah!!!--Sometimes a nights sleep helps out your thinking process!!! I can attach the gear case with two #10 shcs. I wanted to do that yesterday, but I was thinking that the bolts would break through the side of the crankcase in the thin area behind the ball bearing. This morning I see that that is not so, there will be lots of "meat" for the screw threads which hold the gear cover up against the side of the crankcase.

 

[Eccentric]

Brian, don't put steel wool in your muffler, I love the sound of these engines un-muffled. I make it a practice not to count the number of parts I need to make, that way I am always "just a couple of parts away from being done." Looking good, you don't mess around when puttin an engine together, I fiddle with one part longer than it takes you to crank out a whole new design.

 

[Jasonb]

I'm still trying to work out where all those 74 parts are, mine only came to 58 excluding fixings and 8 of those were for the carb

Another vote for an open exhaust stub pipe.

 

[Brian Rupnow]

The two crank-case halves will be right and left hand on a lot of the major features, but there will be a number of features which apply only to one side or the other. The first thing to do before I start cutting and carving is to drill and ream each half for a 3/16" diameter locating dowel. These holes will have virtually zero clearance between them and the dowels so that I don't end up with two crank-cases that don't match up in some of the critical areas. The dowel holes are put into the crank-case halves in areas where they don't interfere with anything else.

 

[Brian Rupnow]

Jason--I do trust my computer on the quantity of parts, but it looks at every individual part. For instance, I have the carburetor designed as a part file, so it only gets counted as one part. The gas tank assembly is counted as 10 or 12 individual parts, and if there are three parts that are identical, the computer counts each one of them.

 

[Larry G.]

So, there we have it. The design is essentially finished. My computer tells me that there are a total of 74 individual components, not counting fasteners. The two crank-case halves are designed to be cut from 3" x 1" aluminum flat bar. The base can be cut from a piece of 2" x 1" aluminum flat bar. I haven't included the poppet valve which screws into the crankcase to keep the crank-case in a semi vacuum condition (to avoid oil leaks around the bearings), because I'm not really sure that I need it. If I find out "after the fact" that I do need it, it can always be added later. The oil filler tube and cap have been added, as well as a drain plug in the very bottom. An "oil level check" hole and plug have been added to the side of the crankcase. You can see it just to the left of the outer gear case. You take out the plug and add oil in the filler tube until it starts to run out that hole. That hole is positioned so that when oil starts to run out of it, you know the oil level is correct. All of the tapped holes and clearance holes for fasteners have been added. The only thing I haven't totally decided on is how to attach the outer gear case to the crank case. If I make it from brass $$$, I can silver solder a couple of mounting tabs to it. If I cheap out and make it from aluminum, then it becomes a different story because I can't weld aluminum.

Make the flat gear cover out of thin (cheap) brass sheet and the thicker curved portions out pf aluminum?

 

[Brian Rupnow]

That doesn't work so well as there is no good way to attach them together.

 

[Brian Rupnow]

I picked up my aluminum for the crank case and base today after lunch, and spent a quiet afternoon detailing. When right and left hand parts are simple, you can get away with one drawing, specifying "One as shown and one opposite hand". When they get fairly complicated there is much less chance of something getting machined wrong if two drawings are made, one of the right hand part and one of the left hand part.

 

[werowance]

Brian, i just saw the start of your build and am posting to subscribe.

one thing i thought might help is on the cylinder, the upshur solders the cylinder to the square mounting plate and works well. could save some cutting and stock waste. but im watching to see how you do it.

also sorry to hear about your fall, i stepped out the door the other morning and slipped, slid across the concrete porch and down 4 steps then halfway across the little stepping stones before i stopped. i got lucky, nothing broken. that black ice will get you.

 

[Larry G.]

That doesn't work so well as there is no good way to attach them together.

Some people like the look of old time riveted pressure vessels. Lots of 4-40 button head SHCS around the perimeter? Black steel alloy or silver SS...

 

[Jasonb]

That's a big crankcase Brian, have you just made it to the original sizes and are going to put a small 1" bore cylinder on it as it looks to measure up more to suit the originals 1.25" bore, and you also have the large 4.5" flywheel.

Although slightly smaller than your 1" my 24mm bore version has a crankcase 62mm tall and 80mm flywheel

You could solder up the gear cover from brass, just a flat plate with a rebate machined around it and then bend some thing strip to form the edge and solder together. If you leave the overall size of the plate larger than needed it can be filed flush to the sides after soldering.

 

[Brian Rupnow]

This morning the 3" x 1" aluminum bar was cut to 2 pieces the correct overall length and then both pieces were drilled thru and reamed for 3/16" alignment rods loctited into the holes to keep the plates perfectly aligned. The two holes for the shafts passing thru were both drilled and reamed to the shaft size (They will be opened up for clearance at a later stage of machining). The five counterbored holes were first drilled completely thru with the correct tap size for #10 thread, then opened up as #10 clearance holes 1" deep thru the first plate, then counterbored. Next step will be to tap the five holes for #10 thread and profile the outer edge of the two plates (while still pinned together).

 

[Brian Rupnow]

So---the "easy" part is done. The sides have all been profiled and the holes drilled, tapped and counterbored. I have some more profiling to do on each side of the crankcase, and then the exciting part starts---machining the inside cavities. The reason that I drilled and reamed the shaft holes "on size" is to aid me when setting up in the four jaw chuck to machine the cavities. I just think it will be easier to indicate off a shaft stuck in the reamed hole than trying to pick up center from the reamed holes.

 

[Brian Rupnow]

Using my time honored tradition of "make it up as I go along"---In order to turn that boss on the side of the crank-case, it's a trick. What I really have to do is machine all the material away except the boss. To do that, I have to be able to hold the crankcase in my rotary table. I need something to "grab onto" with the 3 jaw chuck which is permanently mounted to the rotary table. I can mill 90% of the material away by just mounting the crankcase in my swivel based vice. However, the corners need to be milled away, and for that I need the rotary table. So---I've loctited a piece of 3/8" shaft into the 3/8" bore in the crankcase, letting it stick out about 1" on each side. That will let me do the radius on both sides on the big end. Then I will press that shaft out and loctite a 5/16" shaft into the other end to allow me to radius the other end. Not a really good method for production, but should work fine on a "one off".