Category Archives: Technical Features
Here is the latest installment of the ongoing 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.
Today we’re showing the complete fabrication process of the valve housing and port assemblies from start to finish. The design differs considerably from those you might be familiar with in that both valves and ports are contained in a separate housing that then attaches to the head on the top of the cylinder.
The top photo shows a partially milled piece of alloy steel placed between the three jaw chuck and tailstock on his lathe. In the first thumbnail (below), the port areas have been turned and threaded. Milling operations to remove excess material are shown in the second and third images.
Below you can see the partially machined assembly. Note the smaller threaded female holes visible on top, into which the valve guides will be threaded. The larger diameter male threaded sections are the ports. Another unique feature of this design is the use of a single exhaust valve with two exhaust ports which can be clearly seen in this photo. The solitary intake valve with port are in the foreground. The theory behind this configuration is that the larger area of dual port arrangement would hasten the exit of (expanding) exhaust gases from the cylinder, a practice that has proven incorrect in following years. Today’s engines have just the opposite setup with intake valves and ports of a larger size than the exhaust.
In the next three thumbnails (below) visible progress is being made as Pavel moves from finish milling operations to fine hand filing to remove the milling marks. The right photo shows the machining operation of the ports where they meet the head of the barrel.
And finally (below), you can see how the completed parts fit atop the cylinder barrels. While some last milling marks are still visible on the left, the one on the right hand piece is in it’s finished condition.
When Malanik is finished building this machine, we hope to see it in action at the 2015 Montlhéry Vintage Revival. The photos below show him on his W-4 Torpedo along with his son Pavel riding his replica inline 4-cylinder 1904 Laurin & Klement replica (right). You can look back here to Part II on The Old Motor at the earlier installments of this feature and more of Malanik’s work.
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 of this feature here on The Old Motor 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.
Early, large-engined racing and record setting motorcycles and automobiles have always been captivating to us. Recently we learned of the The North London Garage, J. A. P. Engined Record Holder and did a post on it, telling you all about it and W. E. Cook. In 1909, he set a speed record of 90 m.p.h. (144 km/h) on the Brooklands track in England aboard the behemoth, which carried a huge 165.62 c.i. (2714 c.c.) engine.
Many of the photos in that earlier feature came from master Czech motorcycle restorer, machinist and fabricator Pavel Malanik. The original machine no longer exists, but Malanik, having built other early motorcycle replicas from scratch, does not let minor details like that bother him. He is now in the process of building The North London Garage machine replica and we will be covering the complete project here on The Old Motor.
He has built three other motorcycle replicas in the past that you can see in operation in the following links to videos ; an early single cylinder Laurin & Klement, a 1904 Laurin & Klement with an inline four cylinder engine and a 1908-1909 Trojan & Nagl W-four powered machine, shown above with Pavel in the saddle. You can also see much of his work building that beautiful machine in an earlier post on The Old Motor, watch it in operation in a short video, and use it as a primer for the series we are starting here.
So how do you go about building something that no longer exists? The first step is to find good photos of the motorcycle for reference, and then make complete drawings of the project. The scale drawing seen here (above) was one made in the early planning stages of the project. Key to reproducing the subject is to first establish accurate dimensions and proportions by scaling the drawings and measurements to a part of it that has a known size. Using this method, mechanical drawings of the other components can be made. Those can then be used to fabricate correctly sized parts.
Next you need plan how you are going to machine them using the available equipment and tooling and then work up an order of the metal stock to needed to craft it. The photo (above) shows all of the various special steel alloys needed for the engine. Since making an engine from scratch is the most time consuming part of the project, that is where Malanik started.
The logical place to begin when was with the aluminum crankcase halves, the foundation of the engine. Being an expert machinist, he chose to machine them out of a solid piece of metal instead of having castings made. Both sides of the two piece crankcase are roughed out to the needed inside and outside diameters and width on a large lathe, visible in the center and right photos (above).
After the turning is done on the lathe, the next operations are to machine each roughed out half on a universal milling machine. The left hand photo (above) shows the mill and a crankcase half set up on a rotary table. This allows rotation of the work to facilitate positioning the part, so that all of the different areas required can be machined and indexed precisely at the same time. Also shown in left hand photo (above) is the roughing operation. You can see the timing side half beginning to take shape in the center photo. Most of the fine details, including the lettering, have been completed in the last shot.
The photos above left to right show: slots being cut in the top of the crankcase halves for the connecting rods, face milling the sprocket side crankcase half, and tapping threads for the lifter housings.
In our next post, we will cover the finishing of the crankcase, and then move on to the work involved to machine the cylinder barrels and heads. Check back here on The Old Motor, as it will be a fascinating project to watch as it unfolds. Link to Part II.