Says 53 Guzzi - wish this one had some backstory I could find cause it's clearly got some kind of pedigree.
Oh internet, is there anything you don't know?
Moto Guzzi 500 Four 1953
1953 GUZZI FOUR. An interim development in the 500 c.c.
I-1 class between their 1200 twin, which had been raced since the
early thirties, and their famous Vee-eight was the four-cylinder machine, with its crankshaft in line with the frame, introduced by the Italian Guzzi factory in 1953.
It scored its first victory, in May of that year, at Hockenheim track in Germany where Enrico Lorenzetti won at a record average of 10780 m.p.h., the lap record going to Fergus Anderson on a similar machine at 113-27 m.p.h.
Notwithstanding its impressive debut, the machine turned out to be virtually a failure, suffering from a succession of retirements and "non-starter" trouble—one of the few post-war Guzzi racers that haven't been all conquering!
Technically the machine was very interesting; it was the first four-inline to be raced in modern times (F.N. had similar models in the 1908 T.T.!) and, by virtue of its crankshaft's disposition, the choice of shaft final drive was obvious. The drive shaft casing actually formed one "leg" of the rear pivoting-fork suspension. Front suspension was similar to that of the "250" racer from the same factory.
The engine had no carburetters—fuel was injected direct into each inlet port. No megaphones were fitted to the four separate exhaust pipes, all tucked in under the rider's left foot.
For 1954 the machine had full "dustbin" style streamlining and a frame that was nearly identical with the factory's 500 c.c. single-cylinder model—which was to prove more of a success than its complicated brother.
SPECIFICATION
Engine: four-cylinder-in-line 500 c.c. d.o.h.c; water-cooled; gear drive to overhead camshafts. Ignition: magneto.
Transmission: shaft drive via gearbox in unit with engine.
Frame: multi-tubular "space-frame" with engine unit forming part of structure; swinging-fork rear suspension. Forks: leading link.