Cabin fever leads one collector to build a gas engine from spare parts
Sometimes it is just necessary to invent a project, or build a gas engine, when the weather is cold, snow is on the ground and you’re tired of staying inside.
Going through my excess inventory (junk pile), I found a set of Witte flywheels, a John Deere head, Sparta Economy piston and rod, a Fairbanks-Morse governor, and a crankshaft that worked with the Witte flywheels, though I don’t remember what engine it came from. Having a local salvage yard is certainly a big help in developing projects, so I went there looking for more parts. I found a hydraulic cylinder with an inside diameter that was a perfect fit for the Sparta piston, some C-channel for an engine base and cart rails, well pipe to use as the outside water jacket, a pump off a glue machine, a set of self-aligning pillow block bearings from a shrink wrapper and an oiler off an old metal lathe. Then, it was back to the shop with this wonderful “collection.”
Step one was to find a crankshaft gear, so I used a Fairbanks-Morse ZC 118 as I also had the cam gear and governor from the same engine.
Next, I worked on the pillow block bearings for use as main bearings, the narrow pulley to be used as a drive source for the water pump, and then the flywheels. Starting there determined the necessary width for the engine base, which was made by cutting two pieces of the C-channel from the salvage yard. I bolted the bearing to the C-channel and I had an engine bed.
Step two consisted of cutting the hydraulic cylinder to length, which meant using a few calculations to determine the crankshaft throw distance, as well as piston length and combustion chamber size when the piston is top center.
The next job began by cutting a half-inch steel plate to attach to each end of the cylinder, providing a water jacket as well as something to anchor the head. Upon welding one end to the cylinder (head end), I cut a piece of well casing to provide the outside of the water jacket and then welded this to the first plate. Next, I welded the other steel plate to the hydraulic cylinder and then to the well casing.
I then drilled a hole through the well casing and hydraulic cylinder to provide an access point for the oiler. This was fairly simple to do by drilling a hole the size of a section of 1/4-inch steel pipe through the water jacket and a smaller hole through the hydraulic cylinder to be threaded. I then welded the pipe where it came through the well casing, making the intrusion water tight. This was followed by drilling a 1/2-inch hole in the top and bottom of the well casing for an entry and exit space for water circulation. With those steps finished, it was time to pressure test the water cylinder, and I found a couple of leaks based on the soap test. I got out the grinder and rewelded the spots. The second soap test revealed just one leak, so I fixed that spot again.
Step three consisted of affixing the head to the steel plate, and this was fairly simple by marking the head bolt location on the plate and drilling and taping the holes for the head bolts. I used some recycled 1-1/2 HP John Deere bolts as well as a 1-1/2 HP John Deere head. The advantage of the JD head was the carburetor was cast as part of the head as well as the rocker arm support.
Step four involved attaching the cylinder to the C-channel and keeping everything in line and the correct distance for the piston travel. Luckily, a friend came by the shop and helped hold and clamp everything prior to welding.
At this point, weight was beginning to be a problem with the project so it was time to build a set of trucks. This was rather easily accomplished by cutting four pieces of flat stock and rolling them into a ring. Next, I welded the ring and made a jig for the spokes and center hub. I welded this together and made axles, bolsters and the front turning fifth wheel, cut two pieces of C-channel from the junk yard and assembled. I then welded this assembly to the C-channel that I cut to form the engine base.
I made another trip to the salvage yard to find something to use for a cooling tank, pipe and gas tank. Luck was with me as I found some 1/2-inch brass pipe, a section of box tube and some 16 gauge sheet steel.
Step five was fabrication of the cooling tank. This was not a big deal as I cut the parts with a plasma cutter and MIG welded the tank together. Finding a piece of expanded metal in inventory completed the tank. I then welded a pipe coupling to the bottom of the tank for the pump suction line, and mounted the tank to the engine trucks.
Step six was finding the proper location for the water pump and fabricating an adjustable bracket for belt tightening.
Step seven was the most difficult as it involved making a bracket to support the camshaft gear, camshaft and governor. Getting everything to properly align and making the teeth mesh correctly took several tries. I also had to consider how to leave room for developing a latch-off, as I wanted this to be a hit-and-miss engine.
Step eight consisted of the fabrication of a pushrod, rocker arm, latch off and a set up for contact points to operate a buzz coil. The pushrod and brackets for supporting it were rather simple, and making an adjustment screw to adjust the exhaust valve was no problem. The big difficulty was getting the latch off to work correctly. Fact is, I had to fabricate it a couple of times after the engine was completed to get everything working correctly. The spring tension was very critical.
The remaining issues involved using the junk yard box tube to make a gas tank, installing a check valve and pipe to hook up the gas system, cutting and threading the brass pipe for the cooling tank, and drilling a series of holes in the pipe over the cooler screen. It was also necessary to fit a flat belt to the water pump and crankshaft pulley. I then installed the oiler, an Associated pulley on the crankshaft, and hooked up the buzz coil.
Step nine was trying to start the engine, which went amazingly well except for the hit-and-miss part. It took numerous tries, several modifications and a few bad words for the amalgamation to work. Finally, it was a running engine, except extremely noisy, so I installed a 2 HP Fairbanks-Morse muffler. My wife decided it sounded like a bumble bee, hence the name and color pattern. A local sign shop made the vinyl letters and I attached a brass serial number tag that states “1001.”
In all, the project took four weeks to build, not including painting, and cost less than $200. It sure beat staying in the house looking out the window and complaining about the weather.
Contact Jim White at 7821 Dewberry Lane, Cedar Hill, MO 63016.