Friday, October 03, 2008


So this is the notorious 'Blue Box' which lurked in the basement of the NSU dep't at the Audi plant in Neckarsulm, containing one ultra-rare NSU Works Four-cylinder RS54 dohc 500cc engine.

The engine itself is awaiting some remedial work; while the critical components are in place and in good condition (even the 2 magnetos and 4 Amal-Fischer RN carbs, now priceless - I tried to find a pair for an R51SS, but no dice). The engine isn't in the chassis for this machine as it lacks a sump casting; I'm sure Wolfgang will correct me but I understand this particular engine was used for another purpose (or perhaps just testing), at the end of its racing life, and the sump was removed, and ultimately lost. It will be a relatively simple matter to cast a new one, as it doesn't support the bearings or oil pump, just a cover essentially, and at that point it will be reunited with the chassis. I can't wait to hear it running.

The photo below is from my own archives; it was taken by a US soldier who was an amateur photographer / motorcycle enthusiast, and shows the NSU RS54 in action at the Nurburgring ca 1951, and is probably Heiner Fleischmann aboard. Note the enthusiastic response of the children in the background! 'Go!'

In the two boxes marked 'Spare parts for T.T.' were other NSU gems, including one of the early R11 Rennfox 125cc engines from 1951, with shaft-and-bevel driven dohc, and the funny canted angle of the cylinder head, desaxe the crankcase; see the photos of the whole machine, taken at the Deutsches Zwierad Museum in Neckarsulm (just a few minutes away from the Audi plant, and with a wonderful collection of machines in a converted Schloss). There has been much speculation about why this cylinder head was designed off-angle in this way, but the simple truth is the pressed-steel frame wouldn't permit this large head to fit in the frame any other way. In later models, the cylinder head was redesigned, and sat straight relative to the crankcase.

The R11-51 model also used a petrol tank which was stretched and modified from the original steel roadster item, and lacked the graceful hammered alloy bodywork of the later models.

Still, it has a rustic charm, and was certainly effective on the track, producing 12.5hp @ 9500rpm. I'll make a more thorough investigation of the Works versions of the NSU Max/Fox models as time permits this year; their history is amazing, including the all-conquering 'if it started the race, it won the race' Rennmax model of 1954.

1 comment:

vintagent said...

Hi Paul,
well done great Story. I wonder about reactions of the US Motorcycle Fans about this.
Yes the 1951 Rennfox was built in just 5 Weeks, after a big mess in the 125 Class with naked Lambretta Scooters(which NSU built with a Italians Innocenti License since 1950) - looked like a Cicus Joke not a GP Bike (Italian Rider Romollo Ferry´s weight should´t be more tha 45 kg?).
NSU Racing Team mounted just one original 4 Cylinder Unit(Conrod,Piston,Cylinder,Head) on a modified (after adding special cast roadgoing FOX crankcase with its 4 speed Gearbox to Racing Spec) and put it in a Road FOX Chassis with some modified forks and larger brakes. The first Tanks show that there wasn´t much Time for this.
The Engine you saw in the Box was the last Version of the Schiefkopf Roder R11 Engine.
4 speed shaft and bevel drive right Hand, the last version of the Cylinder Heads wheren´t 4 Cylinder Units, but cast in one Piece with bigger Valves. The First R 11 Schiefkopf had his 4 Cylinder Head with a separate mounted Magnesium Cam Cases, you can see also on the 4 Cylinder Machine.
The last R11 Schiefkopf Heads had also larger Finns for better Cooling (you can see it in the Box). the Secret of the 1953 and 1954 Engines 125 and 250 where the 'bathtub' Cylinder heads with High Compression special Hand made absolutely round Piston Tops. All Engines with this Works Secrets where in these Boxes until VW said in 1969 "all this Motorcycles Stuff should be troughn away,to cast new steel of it" With a great Luck Wilhelm Herz was the Man with the Lorry,to bring this Waste to the Shredder(no he brought it to his Hockenheim Basement,and there the Collection was shown from 1983 in the new Museum.After Wilhelm Died,his Sons shared the money by selling it back to Neckarsulm,because AUDI remeber back his Roots around 1998 when NSU celebrates his 125 anniversery.
Back to the R11 4 speed:
The First update of the 1951 Engine had a terrific international Start: Winning the First GP(1952 Solitude by Werner Haas) for Germany aound 15 HP now and was also used at his last Raced with nearly 17 HP in the Mid of 1953.
This Engine shares the World Title of Werner Haas with its new brother,the fabulous R1153 first 6 Speed Machine on Earth designed by Ewald Praxl wich wasn´t earlyer Redy than the GP of Holland in Assen,the first 6 Speed GP Win.
DOHC left Hand bevelshaft Drive and of course a very good looking Outfit with his straight Head.This Engine didn´t need much Modification to have 18 HP when the Season 1954 began(It won every Race which start,most 1,2,3 in this Year)Most Modifications in 1954 where the Aerodynamics,the used 3 different Fairings in this season,and appeared in MONZA with these ugly looking Full fairing even on the Back of the Bike.This Thing should be the answer of Hollaus´s deathly Crash.H.P.Müller,who was behind him,saw that Hollaus came on his Footrests on the right Hander Lesmo 2.So the rear Alloy Fairing with his Steel Fitments should have had stronger Rear Supension Springs in fact of Downforce and additional weight.The 100 % truth isnt there,but the Internal Papers show this.There are Drawings and mathematic Formulas during the Research of these Fairings in the Windcannel in Stuttgart.Everybody knows how much mass of Wind flows on the Back of a Motorcycle Rider at a Speed of 190km/h,and when you Spoil this on a Thing like This whis was aroung 1mm lenght,thats massive!

The R1154 Engine with a Compression of 1:10,5 had around 20HP in the BAUMM II Hammock when it runs his last Competition in Utah 1956.This was enough for some Years to Beat the Italiens also after 1954.But its over,the Money for trading Roadbikes was gone,and the need Millions to swap from a Motorcycle Manufacturer to a Car Manufacturer.........