Evening Gentlmen
Found an interesting little article.
Cheers
Gilera signed Bossaglia
In the first half of the eighties, Gilera , which was achieving excellent results with its small-displacement "two-stroke", decided to enter the four-stroke single-cylinder road enduro sector.
The engine project was entrusted to Ing. Cesare Bossaglia , who opted for water cooling and for a four-valve dual - shaft distribution controlled by a toothed belt (used to also drive the water pump). The auxiliary balancing shaft was placed in the upper part of the crankcase, and the crankcase lubrication was wet.
Robust and reliable, this single cylinder had several very advanced features , some of which showed a strong influence of automotive technology. The use of a one-piece forged crankshaft (with connecting rod with a cap) that worked entirely on bushings, and an oil pump of the internal gear type, unusual for the motorcycle sector, stood out.
The four valves lay on two planes forming an angle of 30 °; they were equipped with finger rockers with chrome skids when they were driven. The adoption of screw registers greatly simplified the regulation of valve clearance (which is important when performing "on-site" interventions). Inside the cylinder, equipped with integral barrel with a nickel-carbide filler, a forged piston was housed .
The first motorcycle driven by this single cylinder, called Dakota , was presented in the second half of 1985 . The engine was produced in versions of 350, 500 and 560 cm3. The latter had a 98 mm bore and a stroke of 74 mm, and equipped famous models such as the RC 600 and NordWest , which appeared respectively in 1989 and 1991.
“There is a delicate ridge one must ride between fear and reason on a motorcycle lean too far in either direction and there will be consequences.”
Lily Brooks-Dalton, Motorcycles I've Loved: A Memoir
Joachim 
Joachim 
