This is the second in a three part series on Peter Rooke's restoration of a 1 HP IHC Mogul engine. You can read part 1 in Mystic IHC Mogul.
When I purchased the Mogul, it sported a straight piece of pipe as the exhaust and had part of an old union welded to the remains of the original muffler elbow.
The length of pipe was screwed into the union and it took a lot of heat from a gas torch and the combined use of a big vise and a large pipe wrench to part them.
I then sawed the elbow from the original muffler off the union before all the weld was ground away from it to leave the sad remains of the old and badly rust-pitted elbow.
Unable to scrounge any cast iron for this muffler, I purchased two pieces of cast iron so that the muffler could be rebuilt. Fortunately a friend had an original muffler on his Mogul, so I could take measurements to make an accurate copy.
The first part I turned was the main body, and as the supplier sent a bigger piece of cast iron than ordered and paid for, this would also include a spigot for part of the pipe to the elbow. After partially turning the faces of the cast iron, I bored a 1.4-inch hole through its center. I then turned the outer diameter to 4.375 inches, leaving a short length reduced to a diameter of 1.7 inches to form part of the inlet pipe.
Once the outside had been rough shaped, I cut the inside and baffles.
In view of the tight space inside and the need to take fine cuts on the small lathe, this involved frequent tool changes until the profiles had been finished.
Once near the end of cutting the baffles, I used a round nose tool to create a smooth curve to join between the baffles and the muffler body.
I also rounded the exposed edges of the baffles using a form tool that had been made some time ago from a discarded file to turn the ends for ball handles.
Once the body was finished I started the cap. Again I cleaned and turned true the faces of the cast iron before I cut the outside to the outer dimension of 3.9 inches, although in this case I only partly trimmed because some part of it was held by the chuck jaws. I would finish this later when the work piece was reversed in the chuck.
After rough turning to size, I cut the central core with a taper by setting the top-slide over by 18 degrees, and formed the middle baffle using the same procedures as the top.
Finally, I reversed the cap in the chuck so that the outer baffle and lip could be finished.
To finish the top of the muffler, I brazed two strips of 0.5-inch wide by 0.125-inch thick steel in place, followed by four short lengths of similar-sized steel inside the rim to support the cap.
After I cut slots in two places in the outer baffle of the cap to allow clearance for the securing bolts, I taped the cap in place on the main body with four small pieces of steel used as spacers around the edge to keep it central. I then drilled two 0.25-inch holes for the securing bolts, which had been turned with their nuts from some 0.5-inch hexagonal steel.
I then cut some iron tube as a filler piece between the body of the muffler and the old elbow. To make it easy to join it with the muffler body, I cut a step at one end to match a shoulder formed in the top of the muffler. I then brazed the three pieces together.
After assembly, I gave the muffler a coat of heat-resistant paint to complete it.
In a couple of photographs of the Mogul I had seen a thin metal guard covering the gear wheels, and there was also an indistinct picture in the Mogul parts list. This guard was in two pieces and secured to the engine by straps fitting between the magneto and its bracket. I drew a full-size plan and then cut some 0.05-inch sheet metal into two 0.5-inch wide strips, 12 inches long.
It was relatively easy to bend this to shape as the curves could be rolled using the small brake press/roller used in model making. I checked the curves of the two pieces against the outline of the plan, and when correct the sharp folds were completed against a piece of 0.5-inch square bar in the vise.
Once I shaped the two pieces, I drilled a 0.125-inch hole at the top of each piece for the joining bolt.
I used a little trial and error on a piece of thin card to get the shape and folding of the two straps to hold the guard in place. Once correct, I then copied it to some sheet steel. After folding, I brazed these into position.
I then trial-fitted the guard and adjusted it before giving it coats of primer and a topcoat.
When stripping the breather I found that the leather washer on the valve was partially broken. I cut a piece of replacement leather from an old belt, then drilled out the old rivet. I drilled the center of the new leather washer and then securely fixed it in place with a new copper rivet.
One of the oilers had suffered in transit, broken off at the feed tube to the cylinder. As the oilers were a matching pair it was worth trying to repair the broken one.
The first step was to strip the oiler. The glass was also cracked and fell into three parts when I slackened the oiler nuts.
I partially cleaned the thin, broken brass edges and it was clear that the only way to join the two pieces for a seamless match would be to use a jig to hold them together. I turned a piece of scrap steel to provide a spigot to fit inside the threaded delivery section and widened it out to hold the section for the sight glass.
Once this was made, I fitted the two parts on it, adjusting the mating surfaces using files and some light bending to get a good fit. When happy with the fit, I removed the pieces and covered the jig with a light film of oil and covered the edges of the broken parts with flux. Then I put these two pieces back on the jig and I brazed the parts together.
When the braze had cooled, I used needle files to remove surplus braze and tidy up the repair.
While it was possible to get glass to replace the sight tube, the main glass was 1.6-inch over-diameter and to date the nearest size generally available as a replacement has been 1.5-inch. If all else fails, I may have to use some clear plastic tube of the correct diameter.
Unfortunately, I was not thinking straight when setting about the repair of the oiler. While the feed tube was at the crankshaft end of the cylinder I had forgotten that this was a closed crankcase engine and there would still be pressure inside, unlike an open crank engine. There was no check ball and relief tube, and it was impossible to adapt this oiler so it had to be changed for a vented one.
The Mogul arrived on a skid, and while it was covered in dirt there were still traces of paint and even the stencilling of the IHC name.
When the restoration was well underway, I test-cleaned the skid on the underside with white spirit to see whether or not the paint would be damaged by it. This soon revealed that there was more original paint than first appeared, being hidden by a combination of the oil, grease and dirt that the white spirit removed. After cleaning a test section I left it for a couple of days to check that there would be no adverse effects. The test area appeared to be none the worse for cleaning, so I treated the whole of the skid the same way, and then left it to dry.
To protect the woodwork for another 100 years it needed some nourishment. Again, I started by testing on the underside of the skid – I painted an area with some raw linseed oil, wiping any surplus off with a rag. Again, after a few days there appeared to be no harm so all the wood was treated.
The skid had holes through it in various locations and these appeared to tally with a picture of a Mogul in an old catalog. This showed a wheel barrow arrangement, and I immediately printed this picture in as large a size as possible while retaining detail so it could be scaled to enable plans to be produced for the various parts.
I also searched the Internet and Smokstak, and following various leads I eventually got lucky in contacting Charles Wise, who not only provided a series of photographs of an original cart, but was nice enough to also let me have a detailed series of measurements, including the wheel brakes. He even offered to try and get castings made of his wheels, but I decided to have a go at making them.
I decided to draw up some plans so that a start could be made. Although time-consuming, the measurements made it a little easier.
The wheels would be the most difficult items, as they would be fabricated from numerous small pieces. The rims were not a problem as it was possible to get some 10-inch diameter steel pipe with a 0.25-inch wall thickness, and the pipe arrived already cut into two 3-inch pieces.
To keep everything in alignment when welding, I drew a full-size outline of the wheel on the computer and printed it out. I pinned this paper on a wooden board with a steel disc in the middle that the hub would fit over. I then placed the steel ring over the outline and marked the position of the six spokes on both the rim and the hub. I had already marked the center line for the spokes on both the hub and the rim using the height gauge.
I made the hub by boring some 2.1875-inch steel with a 1.125-inch hole for the axle. The six spokes were a little more difficult as they are cross-sectioned. I set the hub and the rim true on the template and then cut the first six pieces of 1-inch wide by 0.25-inch thick iron as spokes. I next cut 12 pieces of 0.375-inch by 0.25-inch iron, then brazed two of them to the wide sides of each trimmed spoke before I rounded all edges using the bench grinder.
Next, I trimmed the spokes to length to be a tight fit between the rim and the hub using the bench grinder before I ground the ends to a knife-edge so that the weld would fill in.
One by one I put the spokes in position. I used a piece of scrap steel to hold each one at the correct height before tack-welding it. After the first one the opposite was then fitted and this continued, working around the wheel.
Once I tacked all the spokes in position, more weld was added, building up the amount around the hub and between each spoke, as well as creating a curve at the rim. A tidier way to have fit these spokes would have been to create a spigot at the rim end of the spoke and then fit this in a hole drilled in the rim before filling the remains of the hole with weld, then grinding flush.
Once I finished the welding, I cleaned up and partially shaped the weld using rotary files and small grinding wheels.
The end result was not as trim as the original, but would still look the part from the other side of the safety rope.
I would use two “U” bolts and channeled blocks to hold the axle in position, using the holes for the original fitting through the wood of the skid.
To make the support blocks, I machined some scrap cast iron into 3.5-inch long blocks, 1.5 inches wide by 0.75 inches thick. I then drilled these with the 0.375-inch holes for the bolts to match the holes in the skid. To create the groove for the axle, I bolted these blocks together using some threaded rod and eight nuts, leaving a fixed 1.3-inch gap in the middle. I set this up using the four-jaw chuck so that the boring bar could cut through the center leaving a 1.25-inch radius curve, a little bigger than the 1.125-inch diameter of the axle pipe.
To slope each end of the block, I held each in the mill vise at an angle to cut away the surplus before I rounded all the sharp edges with the grinder.
To make the “U” bolts, I cut some 0.375-inch steel rod 2 inches over length to allow for inaccuracies when bending and started the 0.375-inch UNC threads at each end. It is easier to start a correctly aligned thread using the lathe and a die holder in the tailstock, rather than freehand after they have been bent.
I held a piece of 1.35-inch diameter pipe in the large vise, then heated the center of the rod red-hot before holding it in a pair of locking pliers and bending it around the pipe. When further bending was needed to get the right shape, I heated the section of the rod to be bent the hottest.
When the bolt was nearly the finished shape, I first inserted the red-hot rod into an axle block, which I then slid over the pipe-former enabling the bend of the bolt to be finish-formed with the heavy hammer.
Once the bolt was shaped, I trimmed the two arms to the correct length after the threads were completed. This required the use of a die-holder with a long reach so the handle would pass over the second arm of the bolt. Finally, I made the four nuts (copying old UNC dimensions) and the washers.
To support the cart near the handle, I needed two pieces of bent iron. Copying the plan, I traced the outline onto a piece of wood with a marker pen (flat steel plate would have been better) to be used as a guide when forming.
I heated a length of 0.25-inch by 1.25-inch metal until red-hot using the brazing hearth, and then bent it to shape using the vise. I wore heavy gloves and I gripped the hot metal with locking pliers. When I needed to make an adjustment to a bend, I heated the section to be bent very hot so that it bent easily. I used a long length of metal bar so there was plenty to grip, and it also gave better leverage. Gradually I formed each of the bends. Then I trimmed the flats that were to rest against the skid to length and drilled the bolt holes to match the old holes through the skid.
Once the two supports had been completed, I made the four 0.375-inch thick bolts and then two plates from 0.25-inch thick steel to fit the other side of the spar.
The original cart had a clamping brake on each side to lock the wheels and prevent them moving when the engine was running, thus providing a solid platform with no vibration. The original bolt holes were again in the side of each spar.
Having a few measurements and photographs of a broken brake, I drew up a rough plan, the holes in the sled indicating that the central bolt was 0.4375 inches in diameter.
For the first step, I used a piece of 0.875-inch steel for the main body of the brake, drilled through with a 0.4375-inch hole for the bolt. While I could calculate the length, I initially cut this oversize to be trimmed to length when all the parts had been made and test-fitted. Eventually, this core piece was 3.5 inches long. I reduced 0.5-inch at one end of this to a diameter of 0.625 inches to slide the inner lip support onto.
I next cut some 1.5-inch wide, 0.5-inch thick steel for the outer lip. I cut this 2 inches long and then drilled a 0.875-inch hole through, half an inch from the top. I then used the milling machine to mill away a depth of 0.25 inches to leave a rib 0.25-inch wide down the middle before I profiled the piece to match a photo of an original. To get the rounded profile, I reduced a piece of scrap 1-inch bar to 0.875 inches to be used as a filing button. I sawed off some of the surplus with a hacksaw before shaping to the round button.
I then cut the packing piece/inner lip to fit between the body of the brake and the wood of the skid to a length of 2 inches from some 0.3125-inch thick steel, 1-inch wide. I drilled this 0.5 inches from the top with a 0.4375-inch hole for the mounting bolt to pass though.
The final piece was the edged arm to fit on the inside to keep the packing piece/inside lip aligned with the outer lip. To save milling a lot of metal, I fabricated this from some 1-inch by 0.75-inch steel, with a 0.875-inch hole through, to which I brazed a 1-inch wide piece of 0.25-inch steel for the top overhang. Once cool, I ground both pieces and then filed to shape.
Finally, I brazed the outer lip in place and made a 6.5-inch long bolt.