Part four in a five-part series: Restoring an Amanco Hired Man
The assembled flywheel showing the governor springs and adjusting screws. The new key and post for the starting handle are also visible.
The flywheels, as befitting an early Amanco, are 2-1/4 inches wide and 18 inches in diameter. They were very rusted so I decided to try and machine them to remove the majority of the pitting from the sides and face.
Unfortunately the maximum size I can turn on my lathe is 10 inches, and the largest lathe I could beg any time on only swung 14 inches. Fortunately my milling machine worked on the horizontal as well as the vertical, and by making a special mandrel to fit the horizontal taper I was able to true up the flywheels.
The pulley was far easier to clean up, as I was able to mount this on a mandrel on my lathe. It looked as good as new when finished with only a modest amount of metal being removed.
The springs and adjusting bolts on the governor assembly needed replacing. The springs were purchased and new adjusting stems made from 1/4-inch steel rods. I also made new square head bolts and adjusting nuts, and cleaned out the threads in the weights.
The floating guide for the governor was very thin from rust and a new one was turned from a 1-5/16-inch length of 2-1/4-inch diameter steel (dimensions for the grooves being estimated from the original, and the size of the 1/2-inch brass bush on the speed detent arm).
The brass bush on the detent arm was misshapen and a new one was made from 1/2-inch diameter brass that left a rolling fit on the arm.
The detent adjusting screw was badly scored and the knurled edge was smooth. Careful work with a triangular needle file restored this edge and a replacement ratchet pin was fitted. The hard steel catch plate was cleaned on an oilstone, as it was not worn badly enough to warrant replacement.
A new fuel tank was required with some pipe work. The fuel mixer was complete, including the ball in the check valve, but the mixture adjustment needle was bent and the whole assembly needed a good cleaning.
A new needle was made using 1/4-inch silver steel that was threaded for one inch of its 2-3/4-inch length and later brazed onto the original brass head. The pointed tip was taper-turned on the lathe. A good fit with the valve seat was ensured by lapping it in the seat with some fine grinding paste.
The spring steel pin that stops the adjustment wheel from turning freely was badly damaged so it was removed by drilling with a carbide drill. A 1-3/4-inch length of 1/16-inch silver steel was brazed in position, heated cherry red and quenched in oil to harden it. This was then annealed to make it less brittle, heated to a dull red for a couple of minutes, and then cooled slowly.
I had the choice of purchasing a completed fuel tank or just the pressings. Being economy minded I opted for the cheaper alternative.
A 1-1/4-inch hole was drilled in the top pressing for the filler and another of 3/8-inch in the side of the base casting for the pipe to the mixer. The fuel outlet was made from a 1-inch length of 7/8-inch diameter brass, of which 3/4-inch was reduced to 5/8-inch to produce a shoulder. A hole was drilled in it and 1/4-inch thread was tapped for the fuel pipe.
The two pressings needed some adjustment to fit together, particularly the top half. The corners were closed up and reformed by lightly tapping them with a mallet on a mandrel of 1-3/4-inch steel until the gaps closed. The joints in the corners of both top and bottom pressings were thoroughly cleaned, fluxed and brazed with a high-melting-point solder. The filler cap and feed pipe were next brazed into their respective halves with standard solder.
The two halves were again cleaned, fluxed and brazed using standard melting point solder. All surplus metal and excess solder was then filed off and the tank was filled with water for a test. After a couple of tests and some touch-up soldering the tank showed no leaks and was ready for the addition of the three securing tabs, which were cut from 1/16-inch steel and soldered in position.
Rather then rely on a closed adjustment needle to shut off the flow of fuel, I fitted a stop tap between the tank and the check valve, making a brass adapter to join up with the tank.
With the addition of some 1/2-inch outside diameter steel pipe fittings, the fuel system was complete and again tested with water. This revealed a leak in the check valve, which had a small crack. This crack was enlarged with a needle file to clean it out, fluxed and filled with braze then filed to make a good repair.
The steel fuel pipe-work and mixer were painted silver in a similar fashion to the original.
The majority of the pitting on the main engine body and cylinder block was masked by the application of epoxy filler and primed. All other parts had been primed with a rust inhibiting primer after cleaning.
Amanco Engines by David Edgington details the correct shade of red paint (ICI Dulux synthetic Coach Finish "Carnation Red" no. P339-224) and general color scheme. After a phone call to check the color code a local outfit was able to mix the paint.
My Amanco model is painted red except for the cylinder head, exhaust, fuel pipe and mixer, which are silver. The gear wheel sides are painted black. The pushrod could also be black, but as this was new it was left as polished steel.
A small spray gun was also used for the red paint and several coats were applied before assembly, masking all studs and apertures, to give a good thickness of paint. I preferred to leave the painting of nuts and studs until after final assembly when they were given a thin coat of paint in order to remove them more easily at a later date.
The cylinder had been fitted to the main body earlier. Using a piston ring compressor and plenty of oil, the piston and connecting rod were fitted into the cylinder block, followed by the crankshaft. The shims for the crankshaft were first replaced exactly as they were before removal and the cap nuts tightened. After scraping the crankshaft, it was a little loose and an equal amount of shim was removed from each side of a cap until there was free turning and no play.
A flywheel was then fitted on the opposite side to the gears. The original keys were damaged when removed, and in any event they did not have a head on them to aid extraction, so new keys were made by milling pieces of 3/8-inch-by-3/4-inch steel. (I favor the use of a steel wedge with a 5-degree taper for the removal of keys).
The new piston rings needed bedding-in. Light oil was liberally applied to both ends of the piston, and through the drip feed hole, then the flywheel was turned in both directions. This was a boring routine and I tended to do this for 10 minutes then go and do something else before repeating. Every so often I would clean the cylinder bore and piston with Kerosene and re-oil.
This was repeated until the piston moved smoothly and there were no sticking points. In this restoration the bedding-in did not take long in view of the poor state of the cylinder bore.
While there was some rust pitting, the gear wheels were generally in a satisfactory condition. The crankshaft gear was fitted over the woodruff key on the crankshaft and the large wheel with the cam was fitted to the body of the engine. When meshing the gears, care was taken to ensure that the single indicator brass stud on the crankshaft gear wheel meshed with the two studs on the cam wheel.
The new guide for the governor detent was then fitted to the crankshaft and the detent (complete with brass bush) pinned in position.
The cylinder head and pushrod could now be fitted, followed by the fuel system.
Finally, the second flywheel was fitted followed by the governor weights and springs. I discovered the springs supplied were too long, with the result that the adjusting bolts were at their limit. Three coils were removed from each spring and the ends reformed.
New grease cups were acquired, and the splashguard that had been spotted and purchased by a friend at a show was fitted. Finally, the pulley was replaced and a new taper peg was made for the starting handle.
Tune in next issue for the next and final job: building the trolley.
Contact engine enthusiast Peter Rooke at: Hardigate?House, Hardigate Road, Cropwell Butler, Notts, England, NG12 3AH; email@example.com www.enginepeter.co.uk