LightAutoA Simple History of the Rear Engined Passenger car

Part Two, Realization.

Dr Ferdinand Porsche set the engineers in his design bureau on project number 12 at the end of September 1931, the design of an economy car. He didn't have a commission for the car, but this was something he wanted to do for some time. By December 1931 the design for a small car was sufficiently advanced for Porsche to look for a possible manufacturer. The main features of the design were, independent suspension on all four wheels using trailing arms at the front and swing axles at the rear, with Porsche patent torsion-bar springs. A three cylinder air-cooled radial engine that was complete with the gearbox and final drive located at the rear of the chassis.
The first prototype of the Tatra Type V570 designed by Erich Ledwinka, the son of Tatra's chief engineer Hans Ledwinka was produced in 1931. Although this prototype had a body of conventional form, the inspiration for the rear engined Tatra came from the idea of taking full advantage of the streamlined forms proposed by the aerodynamicist Paul Jarey. By locating the engine in the long tail, a low hood or bonnet line could be achieved. It had a platform chassis and the air-cooled flat twin engine of 845cc; gearbox and final drive was located at its rear.
Dr Neumayer head of Zundapp, a German motorcycle company was looking for a small car design to produce and the Porsche project No 12 proved of interest. The result was the Zundapp "Volksauto", project. The major change from the original project was the engine. A one litre capacity five cylinder water-cooled radial engine was fitted. Three prototypes were produced in 1932 and extensively tested but the project didn't continue due to financial and business factors.

The Zundapp "Volksauto" Chassis and Body

The first prototype of the Tatra Type 77 was running by 1932, it was a large car in the manner of the Burney and Crossley with a streamlined body. The three litre air-cooled OHV V8 engine at the rear of a platform chassis drove the rear wheels via Tatra type swing axles, that used a pair of crown wheels and pinions that allowed the half axles to articulate each side of the final drive unit. A double wishbone type of front suspension was fitted and transverse leaf springs were used at front and rear.
Tatra 77 Limuzina 1934
Skoda produced the 932 prototype in 1932; it had a backbone chassis with an air-cooled flat four engine at the rear. Skoda didn't develop the design but produced the 420, a front-engined car that had some of the features that were innovative at the time, namely a backbone chassis with swing axle rear suspension.
Skoda 932
Tatra produced a second Type V570 prototype with an aerodynamic body in1933, the project was not continued as the Tatra board decided that the streamlined rear engined concept was to be reserved for limited production high cost cars concentrating on the type77 that was put into production in 1933. The Type 77 and the Type 77A with a 3380cc engine, were in production until 1938 and 249 examples were made. The existing Type 57 would continue to fill the roll of their economy car, which it did until 1948.
Tatra Type V570 second prototype
The next manufacturer that Porsche was able to interest in his design was NSU another German motorcycle company. The next version of the design the NSU Volksauto was a complete redesign, the engine was again changed this time to an air-cooled flat four of 1500cc giving the car a maximum speed of 72 mph. Three prototypes were produced 1933 but again business factors unconnected with the cars design caused the project to be dropped.
NSU Volksauto prototype
Mercedes-Benz produced two rear engined cars in the middle of the nineteen thirties, the 130H and the 150H, “H” stood for Heckmotor. The former had a 1308cc side valve engine located behind the rear axle and produced 26hp. The 130H designed by Hans Nibel had a backbone chassis with independent front suspension by transverse leaf springs and swing axles at the rear. The 150h had a 1500cc engine producing 55hp that was located in front of the rear axle. Ten thousand of these models were produced. between 1933 and 1938.
Mercedes-Benz 130H
Ferdinand Porsche finally found someone interested in his ideas that could find the money and had the power to see them into production. This was Adolf Hitler the new German Chancellor. After Porsche had written a memorandum outlining his proposals, he was given a contract to proceed; this was in January 1934.
The first Volkswagen’s, the three Series 3 prototypes were completed in 1936, after many engine variations had been explored, the design was as the car was eventually produced with a 995cc flat four engine.
The Tatra Type 87 was similar in concept to the Type 77 but was a completely new design, with an all-steel body whereas the Type 77’s body was made of steel over a wood frame. A redesigned front suspension and a new single overhead camshaft V8 air-cooled engine of 2968cc. It was lighter and smaller in overall size than the Type 77 and was in production from1936 until 1950 with a few small breaks due to the onset of war and then peace, in which time 3023 examples were produced. Its survival throughout this period was due to its popularity amongst those in power at that time, from German dictators to Communist dictators.
Tatra 87
The Tatra Type 97 was designed and developed about the same time as the Type 87. The by then classic Tatra form was followed, this time with a 1749cc single overhead camshaft flat four air-cooled engine that produced 40ps, in the rear of a streamlined five seat body. The front suspension with two transverse leaf springs and the rear with Tatra pattern swing axles were similar to the Type 87. With a weight of 1150kg and a wheelbase of 2600mm, it was not a small or inexpensive car but complimented the Tatra range and was in production in 1937. Five hundred and ten examples were produced by 1939 when the production ceased. A myth has grown up over the years, that production of the Type 97 was discontinued by orders of the German government, because it paralleled the Volkswagen.
Tatra 97 Prototype 1936
If you look at the basic similarities in the design this could seem possible, but if you compare the specifications in more detail the idea is unlikely. The Volkswagen only had a one litre capacity engine producing 25bhp, and it weighed 730kg it was an economy car, and designed to be produced at a rock bottom price. If you compare this to the Type 97’s details you can see they were totally different cars. Another factor than emphasised the difference between the two cars was the possible market. The total annual production of the Tatra factory in a year spread through seven different models was similar to the planned daily production of the Volkswagen. An indicator of their possible potential can be gained by studying the post war successors of both cars. As car production ceased all over Europe with some exceptions and turned over to production of war materials, this may have been a bigger factor in its demise.
The true threat to the Volkswagen was the Opel Kadett that at 1450 Marks was near to true cost of production of the Volkswagen. Wilhelm Von Opel boasted to Hitler at the 1937 Berlin Motor Show at the time the Kadett was introduced, that “ This is our Volkswagen”, and for his temerity had his steel quota restricted, limiting Opel’s production capacity.
Thirty prototype Volkswagen cars were completed in1937, the series 30, and used for extensive road testing. In1938 another sixty prototype Volkswagens, the series 60, were completed for more testing.
Volkswagen prototype
As the Volkswagen was being developed, a factory for its production was being built. This and the tooling for production were not ready before the beginning of the Second World War. The first Volkswagen wasn’t produced until August 1940 and only 629 were produced, none of the cars going to the general public, before the factory turned over to producing war materials and military vehicles.
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