[PAR] [TLE] Rolls-Royce Peregrine [SEP] The Rolls-Royce Peregrine was a 21 l , 885 hp liquid-cooled V-12 aero engine designed and built by the British manufacturer Rolls-Royce in the late 1930s.  It was essentially the ultimate development of the company's Kestrel engine, which had seen widespread use in military aircraft of the pre-war period. [PAR] [TLE] V12 engine [SEP] A V12 engine is a V engine with 12 cylinders mounted on the crankcase in two banks of six cylinders each, usually but not always at a 60° angle to each other, with all 12 pistons driving a common crankshaft.  Since each cylinder bank is essentially a straight-six which is by itself in both primary and secondary balance, a V12 inherits perfect primary and secondary balance no matter which V angle is used, and therefore it needs no balance shafts.  A four-stroke 12 cylinder engine has an even firing order if cylinders fire every 60° of crankshaft rotation, so a V12 with cylinder banks at a multiples of 60° (60°, 120°, or 180°) will have even firing intervals without using split crankpins. By using split crankpins or ignoring minor vibrations, any V angle is possible.  The 180° configuration is usually referred to as a "flat-twelve engine" or a "boxer" although it is in reality a 180° V since the pistons can and normally do use shared crankpins.  It may also be written as "V-12", although this is less common.
[PAR] [TLE] Rolls - Royce Peregrine [ SEP ] The Rolls - Royce Peregrine was a 21 l , 885 hp liquid - cooled V-12 aero engine designed and built by the British manufacturer Rolls - Royce in the late 1930s . It was essentially the ultimate development of the company 's Kestrel engine , which had seen widespread use in military aircraft of the pre - war period . [PAR] [TLE] V12 engine [ SEP ] A V12 engine is a V engine with 12 cylinders mounted on the crankcase in two banks of six cylinders each , usually but not always at a 60 ° angle to each other , with all 12 pistons driving a common crankshaft . Since each cylinder bank is essentially a straight - six which is by itself in both primary and secondary balance , a V12 inherits perfect primary and secondary balance no matter which V angle is used , and therefore it needs no balance shafts . A four - stroke 12 cylinder engine has an even firing order if cylinders fire every 60 ° of crankshaft rotation , so a V12 with cylinder banks at a multiples of 60 ° ( 60 ° , 120 ° , or 180 ° ) will have even firing intervals without using split crankpins . By using split crankpins or ignoring minor vibrations , any V angle is possible . The 180 ° configuration is usually referred to as a " flat - twelve engine " or a " boxer " although it is in reality a 180 ° V since the pistons can and normally do use shared crankpins . It may also be written as " V-12 " , although this is less common .
How many cylinders were in the engine of 885 hp, late 1930's Rolls-Royce?
How many cylinders were in the engine of 885 hp , late 1930 's Rolls - Royce ?
12 cylinders
12 cylinders