Hispano-Suiza 12N

12N
Type	V-12
National origin	France
Manufacturer	Société Francaise Hispano-Suiza
Designed by	Marc Birkigt
First run	1928
Unit cost	250,000 FF (1931)
Variants	Hispano-Suiza 18R

The Hispano-Suiza 12N was one of two new V-12 engine designs first run in 1928 and was manufactured by Hispano-Suiza's French subsidiary for the Armee d'l'Air. It produced about 485 kW (650 hp), was the first to use gas nitride hardening and introduced wet cylinder liners into Hispano-Suiza's aircraft engine range. It powered the first non-stop flight from Europe to the United States.

Up to 1927, Hispano-Suiza's many engine types, of various layouts and cylinder numbers, were all recognisable developments of the World War I V-8 Hispano-Suiza 8. 1927-8 saw the introduction of four completely new engines, two V-12s and two with six cylinders inline. The Hispano-Suiza 12N, known by the manufacturers as the Type 61, was the larger of the V-12s, with a displacement of 36 L (2,200 cu in), the other being the 27 L (1,600 cu in) 12M. Apart from capacity and power, these two engines had much in common. The 12M first ran in 1927 and the 12N a year later.

Both 12M and 12N were 60° V engines with carburettors, inlets and exhausts on the outer faces. There were three carburettors per bank, each charging a pair of cylinders. Much of the new technology was in the cylinder design: these types introduced wet liners, an Hispano automobile engine innovation which brought the cooling water into direct contact with the steel cylinder barrel rather than by screwing it into an aluminium water jacket. This improved cooling, simplified assembly and allowed larger cylinder bores without increasing their separation. The cylinder barrels were open at top and bottom and threaded for screwing into the block only near the top, with valve seats ground into the aluminium cylinder head. The lower end of the barrel extended into the crankcase, simplifying both manufacture and assembly. Block and crankcase were bolted together.

...
Wikipedia