Editor’s note: In the December/January issue, we began a three-part feature on Peter Rooke’s latest restoration project. We conclude below with Part 3.
Pushrods and trips
All pushrods and trips had either been sawn through during disassembly or were in need of replacement; easy threading exercises.
The replacement hardened steel roller for the cam follower and its pivot were made out of drill rod. When drilled and turned to the correct dimensions the roller was hardened by heating to cherry red then quenched in brine. It was then tempered by heating to 340 to 390 degrees Fahrenheit (a yellowish color) and then held at this temperature for 10 minutes before being allowed to cool slowly.
The exhaust pushrod and ignitor trip required simple turning and fabrication tasks to copy the originals.
The follower arm for the eccentric strap was cleaned, and the rod and locking bolt threads were cleaned with a tap. A new retaining plate, screws and gib key were needed as they were missing or damaged.
There are several components to the governor in addition to the rod and butterfly beneath the mixer.
The pivots for the governor weights fit in a frame held on the flywheel hub by a locking bolt. The pivot pins for the weights were cut and drilled during the stripping of the engine, as they were rusted solid and not worth saving. New links were made from some 3/16-inch steel, first drilling the holes for the pivot pin and spring. Two discs of steel were turned to match the radii of the link with steps down to the size of the drilled holes. The discs were then used as filing guides to shape the links, which were brazed to the ends of each new pin. Replacement springs were purchased to complete this part of the repair.
The model M being restored is an early model with a threaded speed adjustment knob under the crankshaft bearing housing – dangerous to use when the engine is running. It was necessary to make a replacement, and despite being badly rusted, the governor fork and collar were still useable.
The original collar on this particular engine was not pinned to the bearing housing, unlike some models, and was free to rotate with the flywheel.
Greasers and oilers
The shafts of the greasers were broken or badly rusted, and the caps were little better. Fortunately the cups were not too badly damaged and could be salvaged. It is better to use them with their female threads as they provide a better look than using modern male threads with a connector. Luckily, some caps were found that fit the old cups. And by making new stems, the greasers were as good
The lack of a drip feed oiler was solved by buying a modern replacement, but it did not look right so I decided to make one. Thankfully the bottom thread and drip glass part of the original oiler were found in the sludge of the water hopper, which gave me some dimensions to start with. Using a few photographs it was possible to make a good-looking replica.
The magneto was beyond repair as the alloy casing had crumbled in many places. A replacement was found on eBay and after waiting for three months, it eventually turned up, the postal service presumably sending it via Alaska and Australia! After a clean up it produced a spark. It was given a boost on a magnetiser and was just good enough to run the engine, although starting was a little difficult.
The blanking off plate between the magneto and the main casting had to be replaced so I copied the estimated thickness of the original, 1/16 inch. When fitted, this plate did not press tightly against the engine casing, so rather than enlarge the mounting holes to move the magneto closer, a metal ring was brazed on the sheet metal to fit between the plate and the magneto.
Making a cart for the engine was made easy with all the information available on the late John Hammink’s website (www.oldengine.org/members/hammink/web), where dimensions are provided as well as sketches. The dimensions differed from information provided by other users of SmokStak, which led me to believe that sizes were not set in tablets of stone and were changed by the manufacturers over the years.
It would also appear that different colors were used to paint the wooden skids; the engine color and the lettering style and content varied.
The timber used was cut from some oddments left over from a roofing project, which was sawn and planed to size. It did not matter that the timber consisted of different shades as it would be painted.
The next task was to locate some cast iron wheels. While the word had been passed around farmer friends that I was looking for wheels, nothing suitable had turned up. I was therefore left to use the “best” I had in stock and eventually decided to use a pair of 11-by-5-inch spoke that had been recovered from a ditch and a pair of 9-1/2-by-4-inch spoke wheels that I removed from a two-wheel cart I had made some years ago. I could replace the latter with two solid cast iron wheels that turned up on the doorstep several months ago. The smaller wheels would just pass under the main members of the cart if I followed John’s dimensions. The front turntable support was fashioned from some 3/16-by-3-inch steel plate. As I do not possess suitable bending equipment, other methods had to be used. At the bend points a hacksaw was used to cut a slot on each side. The required shape of the turntable support was measured out and drawn on the metal worktop of my bench, and the support bent to the correct shape using a vice. Narrow v’s were then ground out at the bends and the support clamped on the workbench following the shape which had been drawn earlier. The corners and v’s were filled with weld, and when cool, ground smooth.
A 7/16-inch hole was drilled in the bottom plate for the pivot bolt and four holes in the top plates, filed out to squares for 3/8-inch coach bolts.
A disc of 1/2-inch thick steel was center drilled with a 1/4-inch hole as a pilot hole, and a piece of 1-inch pipe was welded to it. The two axles were made from 3/4-inch nominal pipe, and the middle of the piece for the front axle was centered in the 1-inch pipe. Using the pilot hole in the plate to position the drill, the pivot hole drilled right through. A piece of steel was used as the clamping washer after shaping one side to the profile of the 1-inch pipe.
The wheels that were used had different sized hubs and bores, and neither would fit the 3/4-inch pipe. While the larger wheels could be bored out, the smaller ones did not have the metal, so for both axles I decided to make stub axles, one end of which would fit inside the pipe axle for 3 inches or so. These stubs were held in place with 1/4-inch pins, the ends of which were domed over with a hammer.
The pivot bolt was put in upside down to minimize the overhang underneath the axle and was secured by two locking nuts. A 3/8-inch hole was drilled in the front of the support and pivot plate for a locking pin, and a pin was turned from some scrap steel. The locking pin prevents the axle from turning if you are winching the turntable onto a trailer.
With the front axle completed, the center height of the wheel could be accurately measured. After some simple mathematics the wooden spacing blocks and U bolts were made for the rear wheels. To get the right profile for the U bolts, the 3/8-inch rod was first threaded at both ends, then the center heated and bent round a piece of 1-3/4-inch round steel.
Finally, after painting the wheels and axles, some 1/2-inch steel was shaped to act as the handle. To get the shape right, it was first marked out on a piece of wallpaper. Two pieces, each 52 inches long, were used, with the rings to fit around the axles being formed first by heating and hammering the rod around a piece of 1-inch steel. The two sides of the handle were then shaped to the template and trimmed to size before being welded together.
As I’m not a sign writer, I had to find an easy way to complete the words on the side of the cart. The computer was used to print these out in an appropriately sized type on thick paper, then a modelling knife was used to convert this into a stencil, keeping small tabs in place to support some letters. Masking tape was then used to hold the stencil on the cart side struts, and a thick short-haired brush was lightly loaded with paint and dabbed down at an angle so that the template was pushed against the wood first, before the brush touched the wood. Continuing to use a lightly loaded brush, this was repeated for each letter and again after the paint had dried, until the paint was at the required density. Taking this approach eliminated paint runs and helped to ensure a clean edge to the paint.
Once the lettering had been completed the cart was assembled, and any bolts were trimmed to size then painted.
All painting took place before assembling the engine. Before painting could start, the main casting and other components needed preparation. After stripping, all parts of the engine were cleaned of any dirt and given a good wire-brushing to remove any remaining rust. Unfortunately this meant that all traces of the original paint had disappeared.
In order to get the casting to near its original factory condition, the main areas of rust pitting were given a coat of auto body filler and rough sanded. Next, some powder decorators filler was mixed with an anti-rust primer to make a creamy paste, and several thin coats of this were painted onto the main casting and other rusted components. It is easier to paint several thin coats rather than one thick one, which would require more sanding. The one exception to this was the muffler on which some heat resistant repair putty was used.
Once the filler coats had been sanded smooth, the entire engine was given a final coat of standard primer.
For the top coat, some paint had been ordered from a business that advertised color matched paint for stationary and other engines. They were found from an editorial in an engine magazine that had access to old color charts. The shade of paint they produced was a good match to the originals I had seen.
Several weeks were spent applying paint, first brushing several layers then rubbing down with fine wet and dry sandpaper to get rid of any blemishes. The paint was slow drying and excellent for brushing.
When satisfied with the finish I left the paint to harden for several days before starting to assemble the engine, and any unpainted nuts and bolts were given a thin coat of paint after they were assembled. This took several days, so that by the time the engine was finished the paint was well cured.
For the trial run, the fuel tank was filled with gasoline and immediately there was a problem. Any fuel splashing the new paint did not just mark, but also washed it away, unlike any I had seen before. When I complained that the paint was not fit for a stationary engine I was advised to use their two-pack paint. This was not for amateurs as it contained toxins, which require an air face mask and independent air supply when spraying. Furthermore, it has a short shelf life when mixed.
I experimented with a number of lacquers to see if they would offer protection, but the ones that did had an adverse reaction to the paint. There was nothing else to do other than strip off the old paint and start again. My local auto paint shop matched the color of my original paint, and this time I had a tough finish that was resistant to the fuel.
Assembly was straight forward. Before starting however, I put dabs of white paint on the timing marks of the gears so that they would be easy to pick out when in the casing.
The shims for the crank and big end bearings were adjusted so that there was minimal play in the bearings, yet the crank shaft still moved easily. While tight, the main bearing bolts were not over tightened.
Any joints on the pipe fittings and pipe work were made leak proof, using gas-proof PTFE tape, which also made it easier to unscrew and remove fittings.
New keys were made for the flywheels as the originals had been destroyed by drilling. To get a good fit and at least 70 percent of the key touching the flywheel, they were draw filed to size.
First the keys were filed until the width was a close fit in the key way. Secondly, the flywheels were fitted and engineers blue was thinly painted on the top of the key. The key was lightly tapped into position before being removed again. Where the blue was rubbed off, the high metal was filed down and the process repeated until the key, when fitted with light tapping, had a gap of just over 1/2-inch between the hub and the head of the key.
To draw file, I held the key in the vice, then grabbed the file in both hands and pushed and pulled it, keeping it square to the key at all times.
New decals had been purchased for the hopper block but these had been made from a vinyl type material and did not look as good as the old water transfer decals. In addition, despite trying to store then safely, they had been marked so I decided to try and make some water transfer replacements using my computer.
The images of the old transfers were scanned into the computer and then a photo touch-up program was used to repair the blemishes. The improved images were then printed out on special transfer paper and, following the instructions provided with the paper, the new decals were applied to the engine casting.
Once fully assembled, the engine was checked over to ensure that all nuts and bolts were tight, the timing was right, and that everything moved when it should. As already mentioned, kerosene is more expensive in the UK than gasoline, so there seemed little point is trying to run the engine on kerosene. I will at some stage do it, if only to prove that the engine can run on kerosene and water just as it did when it first left the factory.
The grease cups were filled with grease and turned down until grease could be seen oozing out of the bearing. Then the cup was refilled. The hand plate was taken off to check the big end bearing grease. Squirts of oil were given to all rods, pins, followers and the valve stems, and we were nearly ready. After checking the drain cock was shut, some water was added to the hopper.
Fuel was poured into the tank, the tap on the mixer was set to “Run” rather than “Start” and the pump was pushed by hand to fill the fuel reservoir. Not only did this save me the fiddly job of pouring some fuel into the mixer but it proved that the pump worked.
The drip feed oiler was filled with oil, adjusted to give six drips a minute and left switched on. The choke plate on the mixer was closed and the fuel needle opened half a turn.
Using a starting handle that was a perfect fit, the engine was turned over while the inlet valve was held open to pick up some momentum before releasing the inlet valve. Starting the engine in this manner helped to reduce any risk of kick back and the starting handle damaging your hand.
Nothing happened, and despite some fiddling the result remained the same – not even a chuff. While the magneto had already been tested and found hot, I next found a coil and battery, disconnected the magneto and I tried again. Success! It continued to fire after changing back to the magneto while the engine was running. The magneto just did not have enough umph to start the engine, and at some stage the magneto might benefit from a further session on the magnetiser.
For the next few days, numerous adjustments were made to the magneto timing, the length of the trip rod, governor weights and the butterfly, until the engine was ticking over 500 RPM, slightly below the original 600 RPM, with a steady beat. Another successful restoration completed.