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Screen Cooler Tank

I didn't seem to come across an empty can that matched the dimensions I wanted, so I salvaged a heavily tarnished foot of 2" copper pipe and a coil of 1/8" icemaker line to see what could be done.

Slit the copper pipe lengthwise with a hacksaw in the vise, and then heated it cherry red with the turbo torch and firebrick hearth. Carefully pried it open and then flattened it using the vise jaws while turning over end for end. I have aluminum soft jaws in this vise. Then I was able to form the semisoft copper over a stub of 3" pipe to form a 3" tall by 3-1/2" OD cylinder for the tank. I then silver brazed this and cleaned it up in the lathe on some wooden formers.
The leftover copper had enough for the floor of the tank so that was silver brazed in next, and then again, and one more time until it held water. :rolleyes:
I am using Kapp Zapp 3.5% silver solder in a half pound roll as it is much cheaper per foot compared to the Harris brand. It does work okay with the white flux, but does not seem to work at all on ferrous metals.

I had planned to make three hoops out of the 1/4 OD copper tube, but only ended up using the one as a clamp for the screen. It was too large for the scale, and I ordered 1mm x 4mm half round online to replicate the "bulges" that are found on galvanized tubs and barrels. I was able to mill the tubing into half round pieces after clamping it in an aluminum jig that has a 1/4 ball end mill groove to hold the tubing flat.

Not really sure how the top sprayer part is made, so I sketched a few ideas and ended up with a 1/4" by 3/4" ring with 12 1/16 spray holes. The "hood" is a loose fit over this ring and will hopefully allow the cooling water to cascade down the screen/funnel shape. The screen material is 20 mesh copper.

I wrestled with the screen material enough until I chose to make a wooden former on the lathe. This has a base the same size as the tank (3-1/2") and tapers at 26 degrees. Pinned the screen on the wood and will attempt soldering it another day.
Thank you Chuck

Fuel Tank

I would like to try a different kind of fuel tank for this engine. I remember the old steel fuel oil tanks that people had inside their basements up North for heating. Just so happens that the dimensions are available online so I could get the correct aspect ratio for the typical 275 gallon type. It was scaled to match a piece of 1-1/2 copper pipe I had, and to use up a bit of glass tube for a sight glass.

The copper pipe was sawn in half and the other slabs squared up in the mill. Made the radius for the bulkheads using a compass/scribe and a 6" table top disc sander. I silver brazed it together so it wouldn't come loose later when the fittings and bulkheads were added using softer silver solder. The sight glass fittings were too thin to braze without melting/distorting them. The zinc melted. On the second attempt, I brazed solid pieces and plan to thread and bore them afterwards.

The Kapp-Zapp 3-1/2% solder didn't take well when using the white flux on the large end piece. Had to stop, reclean and use regular plumbers flux. Still need to finish up soldering and add the fill and vent ports to it. What do you think so far?
fuel tank.pngAST fuel tank DWG.png


The fuel tank work continued very well using the plumbers acid flux and 3-1/2% silver solder. Hardest part was the two gauge glass fittings. I would fabricate these parts using solid round bar and thread everything before drilling the internal passages next time. I had to use a 3/16" transfer punch inside the two 1/4" OD brass tubing bits in order to prevent collapsing them.

The fill and vent ports are threaded 5/16-24 with 7/32 across flats squares milled onto the plugs. The glass tube is sealed using small bits of graphite packing in compression. Water tested it both before paint for the solder joints, and afterwards for the glass gauge fittings. I am hoping this tank will be able to set at the base of the engine and not have to elevate it. It may need a structure built to raise it closer to the carburetor level.

looking at these pictures, the sight glass is not to scale but it looks okay in real life setting next to the engine.

Cooling Pump

There is a plan for a centrifugal pump included in Doug Kelley's book. I started the build by drilling the bearing cavity, tapped mounting plate holes and the radius' for the feet. Then centered it in the 4 jaw and machined the shaft bearing profile. I was then able to flip it and use a mandrel to counterbore the areas for the pump shaft lip seal and volute. The pump suction plate was then made in a similar fashion on the mini lathe. The impeller is fabricated from brass bits soldered and then loctited to a shaft. I used a 8 x 16 x 7 metric lip seal as I couldn't find a 3/16" size one anywhere I looked.

I tested the pump using a small drill and may have partially ruined it as the pulley is used to set the end play. I removed the pulley to grip the shaft in the drill chuck. It still pumps but feels "crunchy". I think I will make some brass or bronze washers to fine tune the impeller clearance.

The pump test was used in conjunction with the screen cooler tank and it wasn't a real good showing. Quite a bit of the water ran down the screen as intended, but it overflowed the clamping ring and went onto the ground. This will need improvement and I'm thinking that the screen cone needs to be recessed below the lip of the tank to be successful. I will also remake the upper spray hood out of aluminum and feed it from the side as the weight and the hose wants to tip it over.

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