Engines
Formula One currently uses four-stroke V8, naturally-aspirated reciprocating engines. They typically produce 224 kilowatts (300 bhp, 304 PS) per litre of displacement, far higher than most internal combustion engines. For comparison, the naturally-aspirated piston engine production car with the most specific power is the Honda S2000 engine with 92 kW (123 bhp, 125 PS) per litre.
The power a Formula One engine produces is generated by operating at a very high rotational speed, up to 20,000 revolutions per minute (RPM). This contrasts with road car engines of a similar size which operate safely at typically less than 7,000 rpm. However, the torque (turning force at a given speed) of a Formula One engine is not much higher than a conventional petrol engine. For example, the 2006 2.4 litre Toyota RVX-06 V8 engine produces 552 kW (740 bhp, 751 PS) at 19,000 rpm and outputs 274 N穖 (202 lb穎t) of torque giving the engine a 14.3 bar (1.43 MPa) mean effective pressure. This is comparable with the 14.3 bar maximum MEP of the 2003 BMW E46 M3 CSL, the best production car in this respect.
Consequently, high power is obtained by making an engine turn faster, a goal sought ever since research into performance engines began. The basic configuration of a naturally-aspirated Formula One engine has not been greatly modified since the 1967 Cosworth DFV and the mean effective pressure has stayed at around 14 bar MEP. Until the mid-1980s Formula One engines were limited to around 12,000 rpm due to the traditional metal valve springs used inside the engine to close the valves. The speed required to operate the engine valves at a higher RPM is much greater than the metal valve springs can handle and they were replaced by Pneumatic valve springs introduced by Renault. Since the 1990s all Formula One engine manufacturers now use pneumatic valve springs with the pressurised air allowing engines to reach speeds nearly 20,000 rpm.
The bore is the diameter of the cylinder hole in the engine block for the piston and the stroke is the distance the piston travels from Top Dead Center(TDC) to Bottom Dead Center(BDC) inside the cylinder. A shorter stroke enables the engine to produce a higher rotating speed at a constant mean piston speed but also increases the speed at which the piston must travel in each revolution. Shortening the stroke however requires enlarging the bore to produce a Formula One engines 2.4 litre displacement resulting in a less efficient combustion chamber. The stroke of a Formula One engine is approximately 39.7 mm (1.563 in), less than half as long as the bore is wide (98.0 mm) producing an "over-square" configuration.
A 2.4 litre Formula One engine at 19,000 rpm has a 25 m/s mean piston speed (39.7 mm9000 rpm / 60), the same value as the previously mentioned Honda S2000 engine (84 mm900 rpm/60). This value is typically limited by increasing intake port velocities and frictional losses, but is attained by commercial vehicle engines, like the Honda S2000, BMW E46 M3's S54B32 with 24.5 m/s as far back as 2001, the Audi RS4 with 24.2 m/s or the Yamaha YZF-R6 motorcycle with 23 m/s.
A Formula One engine's high RPM output has been made possible mainly due to advances in metallurgy and design allowing lighter pistons and connecting rods to withstand the accelerations necessary to attain such high speeds. At each revolution, the piston goes from a null speed to almost two times the mean speed (approx. 40 m/s) then back to zero, and then another similar cycle to terminate the circle. Maximum piston acceleration occur at TDC and is in the area of 95,000 m/s, about 10,000 times standard gravity.
The power a Formula One engine produces is generated by operating at a very high rotational speed, up to 20,000 revolutions per minute (RPM). This contrasts with road car engines of a similar size which operate safely at typically less than 7,000 rpm. However, the torque (turning force at a given speed) of a Formula One engine is not much higher than a conventional petrol engine. For example, the 2006 2.4 litre Toyota RVX-06 V8 engine produces 552 kW (740 bhp, 751 PS) at 19,000 rpm and outputs 274 N穖 (202 lb穎t) of torque giving the engine a 14.3 bar (1.43 MPa) mean effective pressure. This is comparable with the 14.3 bar maximum MEP of the 2003 BMW E46 M3 CSL, the best production car in this respect.
Consequently, high power is obtained by making an engine turn faster, a goal sought ever since research into performance engines began. The basic configuration of a naturally-aspirated Formula One engine has not been greatly modified since the 1967 Cosworth DFV and the mean effective pressure has stayed at around 14 bar MEP. Until the mid-1980s Formula One engines were limited to around 12,000 rpm due to the traditional metal valve springs used inside the engine to close the valves. The speed required to operate the engine valves at a higher RPM is much greater than the metal valve springs can handle and they were replaced by Pneumatic valve springs introduced by Renault. Since the 1990s all Formula One engine manufacturers now use pneumatic valve springs with the pressurised air allowing engines to reach speeds nearly 20,000 rpm.
The bore is the diameter of the cylinder hole in the engine block for the piston and the stroke is the distance the piston travels from Top Dead Center(TDC) to Bottom Dead Center(BDC) inside the cylinder. A shorter stroke enables the engine to produce a higher rotating speed at a constant mean piston speed but also increases the speed at which the piston must travel in each revolution. Shortening the stroke however requires enlarging the bore to produce a Formula One engines 2.4 litre displacement resulting in a less efficient combustion chamber. The stroke of a Formula One engine is approximately 39.7 mm (1.563 in), less than half as long as the bore is wide (98.0 mm) producing an "over-square" configuration.
A 2.4 litre Formula One engine at 19,000 rpm has a 25 m/s mean piston speed (39.7 mm9000 rpm / 60), the same value as the previously mentioned Honda S2000 engine (84 mm900 rpm/60). This value is typically limited by increasing intake port velocities and frictional losses, but is attained by commercial vehicle engines, like the Honda S2000, BMW E46 M3's S54B32 with 24.5 m/s as far back as 2001, the Audi RS4 with 24.2 m/s or the Yamaha YZF-R6 motorcycle with 23 m/s.
A Formula One engine's high RPM output has been made possible mainly due to advances in metallurgy and design allowing lighter pistons and connecting rods to withstand the accelerations necessary to attain such high speeds. At each revolution, the piston goes from a null speed to almost two times the mean speed (approx. 40 m/s) then back to zero, and then another similar cycle to terminate the circle. Maximum piston acceleration occur at TDC and is in the area of 95,000 m/s, about 10,000 times standard gravity.
Source: Wikipedia