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.