This is Part II of the feature we have been presenting here showing Czech motorcycle restorer, master machinist and fabricator Pavel Malanik’s progress replicating the 1909 North London Garage Record Holder. He is building the entire motorcycle from scratch and machining the engine from aluminum and steel alloys without using any castings whatsoever.
In Part I, Malanik had finished milling the two crankcase halves out of aluminum alloy in multiple operations. The timing side half (above) and the sprocket side half (below left) are shown after many hours of careful hand finishing and are seen assembled as they will be positioned in the finished bike (middle below).
The next step in building the engine can be seen in the right hand photo (above). It shows one of the two pieces of solid steel alloy chosen for the cylinder barrels in the lathe. It’s held in place on the left in a three jaw chuck and on the right by a live center in the lathe tailstock. Cooling fins will be machined into the cylinders during the turning operations and both will later be lined with a cast iron sleeves.
The work piece can be seen (below) revolving during rough turning operations to get it to the size and form that it can be finished to in the lathe. The cutting tool is held in the top left of the square tool post by a pair of the square-headed set screws. The blue hose dispenses cutting fluid to cool and lubricate the work piece and cutting tool while the cutting operations proceed.
After roughing out the barrel to near net size, it is repositioned in the lathe (below left), with the bottom mounting flange to the right and the top to the left. This photo shows a square grooving tool cutting the first of many cooling fins.
The middle photo (below) shows the drilling operation that precedes boring the cylinder out to a size large enough to hold a cast iron sleeve, which will be inserted later.
The right hand photo (below) shows one of the barrels after it has been finished to size in the lathe and is ready for secondary operations in the milling machine.
In the left picture (below), the head of the milling machine has been rotated to the horizontal. In one of the first milling operations, a cylinder barrel is shown being held vertically in a chuck atop a rotary table to mill the base square in four operations.
In the center photo the now square base is being held in a vice elevated on blocking to raise the work to the milling machine spindle. The holes that are drilled in the flanges in this operation will be used to attach the cylinder to the crankcase. Studs threaded into the top of the crankcase will pass through them to hold the cylinders in position.
In the right thumbnail (below) the top of a cylinder is being machined. The housing containing the intake and exhaust valve assemblies and ports will mount on this top surface of the cylinder. The valves will open down through these holes.
You can take a look back to Part I here and to Part III to learn more about the project. Check back in the coming weeks for our continuing coverage of this amazing undertaking. The next installment will show the machining of the the valve housing assemblies and the intake and exhaust ports.