The Asso XI was a family of

water-cooled Cooling tower and water discharge of a nuclear power plant Water cooling is a method of heat removal from components and industrial equipment. Evaporative cooling using water is often more efficient than air cooling. Water is inexpensive and no ...

supercharged In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. It is a form of forced induction that is mechanically powered (usually by ...

V12 piston

aeroengine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Aircraft using power components are referred to as powered flight. Most aircraft engines are either piston engines or gas turbines ...

s produced in the 1930s by Italian manufacturer

Isotta Fraschini Isotta Fraschini () is an Italian luxury car manufacturer, also producing trucks, as well as engines for marine and aviation use. Founded in Milan, Italy, in 1900 by Cesare Isotta and the brothers Vincenzo, Antonio, and Oreste Fraschini, in 195 ...

, and fitted to a number of aircraft types built by

CANT CANT may refer to: *CANT, a solo project from Grizzly Bear bass guitarist and producer, Chris Taylor. *Cantieri Aeronautici e Navali Triestini CANT (''Cantieri Aeronautici e Navali Triestini'', the Trieste Shipbuilding and Naval Aeronautics; also ...

Caproni Caproni, also known as ''Società de Agostini e Caproni'' and ''Società Caproni e Comitti'', was an Italian aircraft manufacturer. Its main base of operations was at Taliedo, near Linate Airport, on the outskirts of Milan. Founded by Giova ...

and others.

Design and development

Isotta Fraschini produced a long series of engines with the name Asso (Ace in English). The Asso XI R.C. was a liquid-cooled V-12 engine with maximum power output in the range depending on the degree of supercharging. There were two variants, differing only in their supercharger speed: the R.C.40 ran at a little over 10 times the crankshaft speed and enabled the engine to maintain a rated power of to an altitude of whereas the R.2C.15 held to with a supercharger gearing of 7. All variants of the R.C.40 had much in common with construction of the earlier Asso 750 R.C., though they had two, rather than three, banks of 6 cylinders and 4 rather than 2 valves per cylinder. The

cylinder A cylinder () has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infinite ...

barrels were machined from

carbon steel Carbon steel is a steel with carbon content from about 0.05 up to 2.1 percent by weight. The definition of carbon steel from the American Iron and Steel Institute (AISI) states: * no minimum content is specified or required for chromium, cobalt ...

with flat-topped heads and

valve seat The valve seat in an internal combustion gasoline or diesel engine is the surface against which an intake or an exhaust valve rests during the portion of the engine operating cycle when that valve is closed. The valve seat is a critical component ...

s. Each barrel had a separate sheet steel water jacket. Cast aluminium head blocks were bolted to each of the two banks of cylinders, providing valve ports, guides, coolant passages and

camshaft A camshaft is a shaft that contains a row of pointed cams in order to convert rotational motion to reciprocating motion. Camshafts are used in piston engines (to operate the intake and exhaust valves), mechanically controlled ignition syst ...

supports. The pistons were also aluminium castings. The

crankshaft A crankshaft is a mechanical component used in a reciprocating engine, piston engine to convert the reciprocating motion into rotational motion. The crankshaft is a rotating Shaft (mechanical engineering), shaft containing one or more crankpins, ...

was a 6-throw design with 8 plain bearings and a double row ball thrust bearing between the front two. The

connecting rods A connecting rod, also called a 'con rod', is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the crankshaf ...

had bronze bush little ends and white metal

big end Big or BIG may refer to: * Big, of great size or degree Film and television * ''Big'' (film), a 1988 fantasy-comedy film starring Tom Hanks * ''Big'', a 2023 Taiwanese children's film starring Van Fan and Chie Tanaka * ''Big!'', a Discovery ...

s. The

crankcase A crankcase is the housing in a reciprocating engine, piston engine that surrounds the crankshaft. In most modern engines, the crankcase is integrated into the engine block. Two-stroke engines typically use a crankcase-compression design, res ...

was cast in two parts, the upper one with the housings for the crankshaft bearings.

Variants

;Asso XI R:(R - ''Riduttore'' - reduction gear) ;Asso XI R.C.:(C - ''Compressore'' - supercharged) ;Asso XI R.C.15 :Supercharger speed 75/7 times crankshaft; rated power at . ;Asso XI R.2C.15:(2C - second supercharger gearing) Supercharger speed 7 times crankshaft; rated power at . ;Asso XI R.2C.16:(2C - second supercharger gearing) Supercharger speed 7 times crankshaft; rated power at . ;Asso XI R.C.40:Supercharger speed 75/7 times crankshaft; rated power at . ;L.121 R.C.40:A version of the Asso XI, ;A.120 R.C.40: Inverted version of the L.121

Applications

* CANT Z.501 * CANT Z.505 * CANT Z.508 *

CANT Z.1007 The CANT Z.1007 ''Alcione'' (''Kingfisher'') was a three-engined medium bomber designed and produced by the Italian aircraft manufacturer CANT. It was regarded by some as "the best Italian bomber of World War II", although its wooden structure ...

* CANT Z.1011 * Caproni Ca.124 idro * Caproni Ca.134 * Caproni Ca.135 * Caproni Ca.405 *

Caproni Campini N.1 The Caproni Campini N.1, also known as the C.C.2, is an experimental jet aircraft built in the 1930s by Italian aircraft manufacturer Caproni. The N.1 first flew in 1940 and was briefly regarded as the first successful jet-powered aircraft in h ...

* IMAM Ro.45 *

Piaggio P.32 The Piaggio P.32 was an Italian medium bomber of the late 1930s, produced by Piaggio, and designed by Giovanni Pegna. It was a modern design for its time, but was a failure due to lack of powerplants commensurate with its high wing loading. Des ...

* Piaggio P.50 * SAI Ambrosini S.S.4 *

Savoia-Marchetti SM.79 The Savoia-Marchetti SM.79 ''Sparviero'' (Italian for sparrowhawk) is a three-engined medium bomber developed and manufactured by the Italian aviation company Savoia-Marchetti. It may be the best-known Italian aeroplane of the Second World War. ...

(originally)

Specifications (R.C.40)

Note

References