To mark the 120th anniversary of ŠKODA Motorsport, employees from the ŠKODA Museum and ŠKODA AUTO’s Prototype Centre collaborated on a project to reconstruct the ŠKODA 1100 OHC Coupé racing car. The teams began by reconditioning the original frame, chassis and engine and rebuilt the body. In the process, they used state-of-the-art technology as well as traditional techniques in body construction.
Planning for the ŠKODA 1100 OHC (internal type designation 968), which was intended for endurance circuit races, began as early as spring 1956. By the end of 1957, the first of two cars with open GRP bodywork had been completed. This vehicle is still on display at the ŠKODA Museum and regularly competes in national and international classic car events. The second 1100 OHC is part of ŠKODA UK’s heritage fleet.
In 1959/1960, the designers continued working on the project and created two ŠKODA 1100 OHC coupés with closed bodywork. Tried and tested components from ŠKODA’s production models were used. The ŠKODA 1100 OHC Coupé took advantage of a lightweight rigid truss frame welded from thin-walled tubes. Trapezoidal suspension, consisting of two triangular wishbones arranged one above the other, was used for the front wheels, while a coupling axle with trailing arms was installed at the rear.
The engine was located behind the front axle and, along with the assembly unit, comprising rear axle differential and five-speed gearbox, achieving ideal weight distribution. The ŠKODA 1100 OHC Coupé was powered by a naturally aspirated in-line four-cylinder engine. The cylinder and crankcase were made of aluminium and were derived from the ŠKODA 440 ‘Spartak’, as was the crankshaft. However, the racing car significantly exceeded the Spartak’s output of 40 hp (29.4 kW) at 4,200 rpm thanks to its optimised combustion chambers and OHC valve drive, a compression ratio of 9.3:1, two carburettors, double dynamo battery ignition from Bosch, Scintilla Vertex magnetos and many other modifications.
Its output was 92 hp (67.7 kW) at 7,700 rpm, with an impressive 85 hp per litre of displacement. For short bursts, it could reach up to 8,500 rpm. Depending on the overall gear ratio, which could be adjusted according to the specific racetrack, the two-seater with aluminium bodywork and an unladen weight of only 555 kg reached a top speed of around 200 km/h. Dual-circuit brakes always ensured effective deceleration, and to reduce the unsprung mass, rear drum brakes were mounted on the differential gear.
The racing career of the two ŠKODA 1100 OHC coupés lasted from 1960 to 1962. In 1966, they were sold to private buyers when they were no longer allowed to compete due to changes in technical regulations. Subsequently, both coupés were destroyed in road accidents. The surviving components were used in the reconstruction and the original engine was on display for a long time in the vocational school in Mladá Boleslav before it was finally installed in the reconstructed 1100 OHC Coupé.
The second coupé caught fire in an accident and the aluminium bodywork was irreparably damaged. The dismantled, one-of-a-kind rear axle with integrated gearbox had been part of the collection at the National Technical Museum in Prague before it was donated to the ŠKODA Museum 25 years ago. The ŠKODA Museum acquired the truss frame, which had been cut into three parts, along with the complete front axle and other surviving parts from a private collector in 2014.
The most challenging task was to reconstruct the aluminium body. The original designer was the former factory designer Jaroslav Kindl. The carpenters of the time built a wooden model according to his documents. A group of metalworkers hammered out the aluminium panels by hand, and the individual parts were then welded or riveted together.
Throughout the reconstruction, the Museum’s restoration workshop team worked closely with colleagues from the Prototype Centre at ŠKODA AUTO. Based on scans of the 2D drawings on a scale of 1:1, a three-dimensional grid was created. The shapes of individual elements were painstakingly examined and corrected, for example at the front of the vehicle and around the rear lights. Historical photographs were compared with the sketches and the 3D model. The experts were then able to view the car from all sides in the virtual studio and make adjustments. Miniature models were created followed by models of the front and rear body corners on a 1:1 scale.
The bodywork was created from 0.8 mm and 1 mm thick aluminium sheets that were manually welded and beaten to shape during the reconstruction. Originally, both coupés were unique, featuring an anodised finish. On the track, however, this surface treatment failed to demonstrate any benefit, and so both cars were painted red in the middle of the 1962 season.