The design of the Prinz III’s replacement was all set for production, until BMW launched its 700 model in 1959. Bearing an uncanny and completely co-incidental resemblance to the new BMW, the NSU board decided that changes had to be made to the styling, otherwise there was a very real danger that the new 1961 Prinz 4 would look like a clone of a two-year old BMW.
Claus Luthe, the man who had developed NSU’s design department was instructed to overhaul the Prinz 4 and he drew inspiration from a board member who had recently visited the USA. The result was that the Prinz 4’s eventual design was so thoroughly reworked that instead of resembling a BMW 700, that it looked like a Chevrolet Corvair which had been shrunk in the wash.
Mechanically, the Prinz 4 was just like its predecessors – incredibly well engineered. Powered by a rear-mounted, air-cooled vertical two-cylinder engine which owed its eccentric rod-driven camshaft design to NSU motorcycle engine practice, it also featured a clever combined starter/generator – dubbed a Dynastart – which was built into the crankcase. Suspension was all round coil springs with the front benefiting from double-wishbones and incredibly, coilover units. It even had the option of ditching the beautiful alloy finned drums, for disc brakes at the front.
In 1963, the Prinz sired the larger bodied NSU 1000, 1000TT, 1200TT and TTS models – cars which were powered by over-head cam, aircooled four-cylinder engines with conventional starter motors and alternators. The 1200TT and 1200TTS in particular went on to forge very successful motorsport careers, because of their combination of low kerb weight, excellent handling and engines packing plenty of pizzazz.
Two years later, NSU introduced the ‘extra-large’ model, the Type 110 (later renamed NSU 1200 – not to be confused with the 1000-based TT and TTS) – it may have offered more passenger room, but sadly it wasn’t as much fun as the 1000-based models.
Ironically, given that NSU built the Type-32 – a car which would turn into the Nazi-sponsored Kdf-Wagen – VW would once again benefit from NSU’s engineering expertise. In 1969, after NSU was weakened by warranty problems with the clean-sheet, rotary-engined Ro80, the company was bought by VW and merged with Auto Union to form Audi.
In 1973 the Prinz 4 and its rear-engined relatives were phased out, because production capacity was needed for the new upmarket Audi models. The NSUs were therefore replaced by the Audi 50 – later Volkswagen Polo – in 1975, a car that sat beneath 1974 Golf in the VAG range.
Few contest the argument, that without NSU, VW would have remained unable to effectively replace the ancient Beetle and the hot-hatch revolution would have started elsewhere. Indeed, it is often speculated that the real reason the Prinz 4/1000/1200 range was canned, was that it was too hot for VW’s old bug to handle…
Crawl up, over, around and through a Prinz and you’ll see that NSU were years ahead in the art of rust-prevention. However, good though it is, you will encounter the odd breakout here and there. Depending on the year of the Prinz you’re checking, floorpans can either be good news or not so good news. Generally speaking, the later the car, the better the floor’s ability to withstand rust’s unwanted advances. Doors tend not to suffer from corrosion, but it’s better to be paranoid than sorry. Under the bonnet you can find rust on the sides of the wheelarches, while all four wheelarches can rust through. Also pay close attention to where the front wing meets the scuttle panel. Finally, bootlids and bonnets are pretty good at not turning all lovely-bubbly – so if there is any rust, move on in for a closer look because this isn’t usual.
Here is one of the reasons that the Prinz’s offspring were really rather handy on the track – all round independent coil suspension. Although an inexperienced driver would soon find out why they became known as the ‘Heckschleuder’ or ‘Tail Spinner’… Check the front nearside kingpin which can seize and while you’re down there, examine the nylon seals on both sides because these can fail if the kingpins haven’t been greased. At the rear, the telescopic dampers are located by circlips and its essential that these are still in-situ. Unlike many German cars of the period, the Prinz features rack and pinion steering – so if there is excessive slop, don’t mistakenly presume it’s because there’s a steering box up front. If you hear a thud, then you should check immediately to see of the rack’s adjusting bolts are loose.
- Engine NSU 598cc rear-mounted, air-cooled, vertical two-cylinder with eccentric link rod drive OHC, 76 x 66mm, single down-draught carburettor with air silencer, mechanical fuel pump, twin coil ignition. Maximum power: 36bhp @ 5500rpm. Max speed: 75mph. Fuel consumption: 50mpg (approx).
- Transmission Single-unit drivetrain incorporating engine, gearbox and rear axle casing. All-synchromesh, four-speed gearbox with remote central gearchange. First: 18.74:1; second: 10.0:1; third: 6.39:1; top: 4.52:1; reverse 24.35:1. Single-plate dry clutch, spur final drive.
- Suspension All around independent via coil springs and telescopic dampers. Front: double wishbones with coilovers; rear: swing axles with separate coil springs and telescopic dampers. Steering: rack and pinion.
- Brakes All around hydraulically assisted aluminium finned drums. Front discs optional.
- Wheels Five-stud pressed steel wheels with 4.80-12 tyres.
- Sept 1961: Prinz launched in Germany
- Feb 1962: Prinz launched in the UK for £687 10s 7d 19d
- Dec 1962: Roof and bonnet given strengthening ridges
- Feb 1963: De Luxe model introduced, featuring full-width bumpers and over-riders
- Aug 1964: Base model introduced
The complicated valve gear should be quiet, but such was its complexity that it dissuaded many owners from servicing the car themselves – so if it’s noisy, there could be a problem. Pre-’64 cars suffered from camshafts that, because they were soft, suffered from premature wear. Later camshafts were harder and NSU had a cam replacement programme in place during the Sixties, so it’s highly unlikely a car you’re looking at has the earlier type.
The engine is shrouded by cooling ducts but beware of oil leaks on engines fitted with a pressed-steel rocker cover – if it’s been over-tightened it will warp, which in turn leads to oil leaking. Later models used an aluminium cover that is less likely to warp.
One delightful component is the dynastarter, which combines the starter motor, generator and distributor in one neat unit; it’s built into the end of the crankcase and is permanently attached to the end of the crankshaft. If properly maintained it should be quiet and efficient in use, if not, neglect could will lead to a charging problem. The bushes and springs should be checked regularly.
The gearbox should be quiet in operation and gears should be easy to select – well, as easy as a remote gearchange can be. Problems selecting reverse? This could be due to tired engine mountings, which can lead to the engine sitting on the selector rod.
NSU Owners’ Club UK – see www.NSUOC.co.uk Thanks To: Mike Bevan, NSU owner and enthusiast extraordinaire, The National Motor Museum.
Alright, the Prinz 4 doesn’t come with a lovely little screaming engine like an Imp or a FIAT does, but then the NSU won’t turn into a pile of sludge at the first whiff of rain… You only have to look at its five-stud 12 inch wheels to realise that this is one over-engineered little car.
Yes, it is tempting to install a four-cylinder from an NSU 1000 or 1200, but the Prinz has a shorter wheelbase and the four-cylinder has a different transmission design. So even if you could find one of these engines, it would be quite a job to install one. To be perfectly blunt, why bother? When there is plenty of room back there and we have the benefit and choice of modern power units from which to choose. (Oh and if you think we’re all talk and no trousers, keep logging on and we’ll prove this point).
Look at the quality of the Prinz’s suspension design – particularly that double wishbone coilover front – and it’s begging for something spicier to punt it at along than a mere 36bhp. It’s unusual, individual, full of period Sixties loveliness and it wreaks of quality, so what are you waiting for? Get busy.
Dep-O Needs You!
This Prinz 4L was rescued from a scrapyard in Gloucestershire just as it was about to be baled and weighed in. Unfortunately, we can’t find any clue of its past life or more importantly, its registration plate.
Do you know anything about our car or do you know someone who might? Why was it taken off the road? The brakes have been disassembled and the clutch appears to be AWOL.
All the previous owner has left as a clue is a ‘The Prisoner’ Number Six sticker in the rear screen and a Microcar Club sticker in the windscreen.
Get in touch and give us a clue, because we want to get this little orange oddball back on the road as soon as possible.