KIM NEWCOMBE AND THE KONIG 500 GP
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Story by Graham Clayton I Photos Courtesy of Norman White
ieter Konig’s venture into building a 500 cc GP racing motorcycle began in 1968. Konig was the chief engineer and boss of the Berlin-based Konig Motorenbau family business that over the previous four decades had developed considerable expertise in the building of high performance two-stroke outboard engines with which they won many hydroplane races and set numerous world marine speed records. Konig had taken over a one-off road racer project started by local racer Wolf Braun when injuries and financial difficulties forced Braun to abandon the project. Braun’s racing special was powered by a Konig longitudinal 180-degree flat-four twostroke marine racing engine fitted into a much-modified BSA frame fitted with road racing suspension and brakes. The Konig ‘marine’ engine was cooled by cold water drawn from the water course on which the boat was being operated. Its conversion to use as a motorcycle engine would critically depend on the development of an effective on-board cooling system. In addition, the marine engine had a straight drive which meant that a racing gearbox and clutch had to be developed for its use in a racing motorcycle. These two area areas would prove to be problematic for the new racing machine for a couple of years as various solutions were tried, proved to be lacking and replaced. While Dieter Konig had a lot of two-stroke engine expertise, he knew relatively little about racing motorcycles. Fortunately for Konig a New Zealand-born engineer named Kim Newcombe approached him looking for a temporary job until he could take up a position with Maico in March 1969. Newcombe had worked in Australia for a marine dealership and was familiar with Konig engines. He was also a successful motocross and speedway racer in Australia where he had raced Maicos for their Melbourne importer Modak Motorcycle. The move to Europe and Maico was part of Newcombe’s motocross career plan. Konig hired Newcombe as a marine engine development engineer, but soon made him the lead man on the Konig 500 GP racer program. The Konig 500 GP engine consisted essentially of two flat twins with their cylinders facing fore-and-aft much like an early Douglas twin. The engine employed a single shared three-bearing crankshaft housed in a common bottom end, but with each side’s pairing of front and rear cylinders having their own individual sealed engine case for separate pumping chambers. The original bore and stroke were both 54 mm that produced a swept volume of 494.7 cc. The Konig ran on a premix of gasoline and oil at a ratio of 16:1. This was fed into the paired twins’ cylinders via a rotary disc valve mounted flat on top of the crankcases. The rotary disc valve was driven by a rubber toothed belt directly from the right-hand-side (RHS) main shaft. With the help of two rollers, the belt drive turned through 90 degrees, up and over the top of the engine to rotate the rotary disc valve. The two BVF carbur-
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etors fed fuel through the rotary disc to either the right or left pair of cylinders. Originally the exhausts of all four cylinders were fed into a huge crude-looking single canister-like expansion chamber. This was soon replaced. In the revised exhaust each pair of front and rear cylinder exhaust ports was fitted with a very short siamesed two-into-one exhaust header pipe. Each siamesed header routed exhaust gases through a single large expansion chamber upward and backward over the engine. Liquid-cooling for the engine employed a large rectangular radiator mounted to the frame’s front downtubes, plus a cast magnesium water tank (sump) bolted to the bottom of the engine, both of which were fed by a rubber band-driven water pump located on the right side of the motor. The use of the bottom-mounted sump to cool the engine cases required that its four cylinders be reversed so that their exhausts exited upward above the engine rather than downward. It also required that the gearbox be located at the back of the engine on its right side which resulted in a relatively long wheelbase. The primary and final drives for the bike were on the left side of the engine and utilized a toothed Westinghouse chain driven off the end of the engine’s crankshaft. The basic ignition system for the engine consisted of a battery, two sets of points and twin ignition coils. By late 1969 Kim had made significant progress improving the race-worthiness of the 500 GP and forgotten about the move to Maico. Newcombe had never planned to be a road racer, but by the fall he decided to race the Konig himself in a German Junior Championship race on the Avus street circuit in Berlin. It was his first ever road race and he won. It’s fair to say that Newcombe was a natural when it came to racing motorcycles. 1970 was another development year for the 500 GP, but Kim Newcombe found the time to enter and win five more German Junior Championship races ultimately making him eligible for an FIM GP licence. For 1971 Dieter Konig decided to hire Australian
