ALFA had just been incorporated by Nicoli Romeo in February 1918 and became Alfa Romeo and Nicola Romeo, with the zest only the truly converted can muster began to develop his new company. Nicola Romeo was not a car enthusiast before he purchased ALFA he produced mining equipment. With the beginning of the first world war he produced compressors for the Italian Army who were fighting against the Austro Hungarian Empire and at this time he needed to acquire as much factory space as he could to produce compressors and shares in ALFA were being sold of by Banca Di Sconto and he bought them, As a self made man who's company had grown by over 1000% in one year this was, at the time just business sense.
With the coming of peace he realised he had an asset that could be exploited and the first design the factory bought out was the G1 a design that harked back to the Edwardian era. However Alfa Romeo had managed to recruit one Enzo Ferrari to their racing team and he partnered by Ascari, Campari and Ugo Sivocci, the three musketeers, proceeded to make a name for themselves, it was at this time that Francesco Baracca presented Ferrari with "Il Cavallino Rampante" which has graced the flanks of many of the greatest cars in history. Ferrari had a talent for organisation that far outshone his gifted driving abilities and together with Nicoli Romeo they recruited Vittorio Jano to help produce racing cars and so began one of the most successful racing partnerships ever.
The first car Jano produced was the P2 and this was a 2.0 litre which was supercharged to produce 140 bhp at 5500 rpm, not an excessive amount by today's standards but good enough in its day to win a GP or two. In order to exploit their racing successes the road cars were to copy many of the racing cars design features, The Alfa Romeo NR, which was soon renamed the 6C 1500 was a six cylinder engine rather than an 8 cylinder but the bore and stroke were very similar the bore being increased by 1 mm and the stroke was decreased by 3mm to give a capacity of 1487 cc. the cylinders were cast in a block and this was bolted to a light alloy crank case, the valves were arranged in a single row and operated by a single overhead camshaft, the fundamental difference between this engine and the P2 being the lack of the extra camshaft, the single cam was driven by a bevel gear from a vertical shaft as was the P2. The mixture was fed from a single Carburettor to all six cylinders and the mixture was compressed by a very slightly domed piston and ignited by a spark plug which came in at right angles to the bore and this was fired by a coil not a magneto which also was a major advance on its predecessors.
The chassis was also a significant advance on the RM while the chassis was widened by a small amount and the wheel base was maintained the chassis was lightened by 1/2 a ton this coupled with an engine that produced 4 bhp more (a 10% increase) was a significant advantage and the 6c 1500 could top 70mph. The 6C 1500 was first shown at the Milan Motor Show in April 1925 and was highly acclaimed by those in the know (where have you heard that before) and it was not until the sport version was released that the 6C 1500 really came into its own.