Corvette XP-897GT Two-Rotor, 1973. A mid-engined prototype with a 180hp twin-rotor Wankel engine which was built on the platform of a Porsche 914 by Pininfarina. It was displayed at the 1973 Frankfurt Motor Show but the cancelation of the GMRCE (General Motors Rotary Combustion Engine) program meant the XP-897 never made it into any Chevrolet showrooms
Citroën GS Birotor, 1973. A version of the GS fitted with a 109hp twin rotor engine built by Comrotor, a joint venture between Citroën and NSU, and a semi-automatic gearbox.The Birotor was more luxuriously trimmed than a regular GS, featured 4-wheel disc brakes and flared wheel arches. It cost 70% more than a GS making it similar in price to the larger DS. It used more petrol than the DS as well and was launched in the midst of the 1970s oil crisis. Naturally it was a sales disaster with 847 cars being sold in total. In fact Citroën attempted to buy back all of the GS Birotors they had sold rather than face the need to honour warranty claims (they quickly developed a reputation for unreliability) and supply servicing and spare parts. A few cars have survived in the hands of collectors.
I think the GS Birotor (sometimes also referred to a the GZ) is my ultimate car that never made it. Consider the ambition behind the engineering, hydropnuematic suspension, rotary engine, highly aerodynamic design. In 1973. It helped to bankrupt Citroën driving them into the arms rival Peugeot
Corvette Four Rotor, 1973. The ultimate development of the Corvette rotary program, the Four Rotor used two twin rotor engines bolted together to create a 420hp mid-engined supercar. The design was by Henry Haga under the direction Bill Mitchell and the car was displayed at the 1973 Paris motor show. The 70s fuel crisis and cancelation of GMs rotary engine gave it no chance
Corvette XP-895 Reynolds, 1973. Designed at GM’s studio under Charles Jordan and William Mitchell, the second XP-895 was built by Reynolds Metals Company modifying the first steel body in aluminium. Instead of the twin rotor engine this prototype is fitted with a 454ci V-8. Chevrolet’s general manager of the period, John DeLorean, explored productionizing the aluminium-bodied mid-engined XP-895 but found it too be uneconomic.
A Bristol Type 192 Belvedere displaying at Farnborough in 1961. Though their service life was short these twin-engine British
tandem rotor helicopters served well during the Aden Emergency and later in Borneo. Just three complete airframes survive today.