Through the years I collected a lot of pictures of two stroke racing sidecar engines. It all started with König and their 4 cylinder boxer engine, at the same time Rudi Kurth created a triple Yamaha 500. After that four cylinder Yamaha TZ500's were used. They were replaced by TZ500 clones made by JPX, Krauser and ADM, these engines had reed-valve crankcases and could use more modern barrels with power-valves. They still used a lot of TZ500 parts, such as the cranks and clutch. The unreliable gearbox was often replaced by aftermarket ones like ARCO from Italy. Egbert Streuer kept using TZ500 engines and modified the uppercases for reed-valve use and modern barrels.
In the early ‘90s Swissauto developed its own version of the Krauser 500cc inline-four crankcase reed-valve two-stroke motor by then ubiquitous in the Sidecar GP class, and Switzerland’s four-time World champion Rolf Biland raced the result, winning a further hattrick of World Championships in 1992/3/4. “We made everything new inside, including the gearbox,” said Wenger, “and though we used the original Krauser crankcases, we modified the upper half quite heavily, because we were the first people to use the 54 x 54.5 mm configuration in the Sidecar class. We developed it to give more than 180 bhp by the end of the ’94 season.
When the two stroke engines were replaced by four strokes it all ended with the great Swissauto V4 raced by Rolf Biland. Wenger claimed the V4 engine was originally only intended for solo use. “The inline four-cylinder engine is absolutely the best format for Sidecar racing,” he asserted, “but only for that. However, the V4 engine is much lighter, so even though we designed it for solo racing, the Sidecar guys wanted to use it, too. We took pole position with it in every Sidecar GP in 1995, won five out of the seven races, but lost the title because our drivers Biland and Guedel took points away from each other, and let Darren Dixon win on the ADM!” However, fast as the five Swissauto V4-powered rigs were in every race, they also suffered a series of mechanical failures that were an inevitable part of the new engine’s R&D.
Egbert Streuer and Rinus Dorgelo made the Stredor, unfortunately Egbert never raced it. It is a two stroke boxer engine with 200 hp. First they
used Honda and Yamaha cilinders, at the final version Aprilia ones.
For more pics see
Rolf Biland warming up the Swissauto
Egbert Streuer testing the Stredor
Wietse Veenstra on his Norsaki 500. In 1969 Wietse started racing in the 500cc national class in the Netherlands. First on a standard Kawasaki 500 triple, after a hard crash the Kawa was total loss. With the engine out of the wreck and a Norton featherbed frame he made this bitza. The thing was very fast and in 1971 he became the Dutch national champion in the 500cc class with 5 wins and 2 second places. I would really like to know what became of the bike, you can email me via the contact page on this site. 
