Sidecar racing engines

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.

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Sidecar racing engines

Rolf Biland warming up the Swissauto

Swissauto V4 1

Swissauto V4 2

Egbert Streuer testing the Stredor

Stredor 500

The Aprilia 250 GP bike

The year is 1985 and the debut of an extraordinary GP bike the Aprilia in the GP 250cc class is a fact. The first bike has an alloy aluminium dual beam frame with a Marzocchi fork and a rear monoshock mounted on a pro lever type suspension. The engine is a two stroke Rotax tandem twin. In the debut on 23 March 1985 in Kyalami South Africa Loris Reggiani finishes 12th. For the rest of the championship the bike performs so well that Reggiani takes a third place at Rijeka and repeats this in Imola. In 1987 the Aprilia 250 rises quickly to the top. A new chassis and V-twin engine take it to second place (Salzburg and Rijeka). Victory is within reach and comes at Misano. The date is 30 August 1987 and Reggiani rides his AF1 250 to its first success in a Grand Prix race. In 1991 the bike configuration changes from AF1 to RSV (production bikes) and RSW (factory bikes). After three consecutive 250cc world titles for Aprilia with Biaggi from 1994 to 1996, the title is in 1998 for Loris Capirossi, as he beats fellow Aprilia rider Tetsuya Harada on the last corner of the last race in Argentina. The late 1990s also saw Valentino Rossi thrilling race fans on Aprilia machines as he won the first two of his total of nine World Championships, in the smaller classes. Rossi spent his first four years in Grand Prix racing on Aprilia bikes, winning the 125cc title in 1997 and the 250cc crown in 1999, before he moved up to the premier class. In 2007 the configuration changes to RSA. The last 250 World Championship on an Aprilia was for Marco Simoncelli with a bike under the Gilera brand, he succeeded in 2008. 

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Tandem twins

V-twins

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Ex Preining AF1 250 V-twin

Kim Newcombe

Born in Nelson, Newcombe grew up in Auckland, then moved to Australia (first Brisbane, then Melbourne) in 1963, and subsequently moved to Europe in 1968. He competed in the 500cc Grand Prix World Championship finishing second to Phil Read in the 1973 season on a König 500 developed completely by himself.

Read the amazing story about Kim and the König here

Kim Newcombe not forgotten

For pics of this awesome bike see

König 500

Suzuki GSXRG500

When you think you have seen all the Suzuki RG500 frame combinations, this bike pops up at Facebook. It is a combination of a Suzuki GSXR400 rolling chassis and an RG500 engine, made by Mark Walker. 

Want to know how it sounds see 

Suzuki GSXRG500

Mark Walker also makes some very trick stuff for the Suzuki RG500, like frames and dry clutches.

For pics of his parts see

Mark Walker RG500 parts

The golden era of sidecar cross

The eighties were the golden era of sidecar cross racing, this was the time of the big two stroke twins, Startwin even produced a four cylinder boxer engine. The leading companies were EML with their Jumbo and the Swedish Folan. Dutchman Jerry van der Heiden produced a Vtwin KTM engine for Ton van Heugten. Husqvarna made a prototype, the Proof 2000 with a Folan engine. 

For more pics see 

Sidecar cross engines

Want to know how they sound?

Folan sidecar

Hi-Tac Suzuki 500

Barry Sheene on the very special Hi-Tac Suzuki 500 two stroke twin. The Hi-Tac was Peter Inchley's (ex-Norvil chief) project, started in 1972. He saw that water cooling was desirable for two strokes and designed a thermo-siphon kit for the T500 (before Suzuki's own watercooled TR III). 

For more information and pics see 

Hi-Tac Suzuki 500

Lotus Rotorvic V12

This amazing assemblage is the V12 Rotorvic two stroke which appeared in British club racing in 1965, powering a specially modified Lotus 23 sports car. It consists of six Ariel Arrow two stroke motorcycle engines disposed at an included angle of 90-degrees and driving the central shaft. Transmission was via a Hewland five-speed gearbox and the engine was cooled via huge air-scoops in the body panelling. This 1482cc V12 made a ferocious noise and it was almost impossible to tell it was misfiring on one or two cylinders. It produced 220bhp at 10000RPM. The creator was R.V. Marchant and the driver was Bill Hill.

For more pics see

Lotus Rotorvic

Want to know how it sounds?

Lotus Rotorvic Youtube