Formulary Generally Axle Load Distribution Payload Distribution Braking Distance Driving Force Work/Energy Radian Measure Tension (brake) Brake Force Brake Pedal Brake Force (wheel) De-/Acceleration Braking Distance Braking Period CO2 emission Density Torque Pressure Injection Quatity Electrical Power Riding Speed Centrifugal Force Gas Speed Speed Coaxial Gearbox Lever Ratio Hollow Cylinder Stroke-bore Ratio Displacement Power Output p.l. Hydraulic Ratio Capacity Piston Speed Piston Force Force Crank Mechan. Forces Fuel Consumption 1 Fuel Consumption 2 Fuel Consumption 3 Ciruit Area Circuit Ring Circumference Clutch Pedal Power (mechanical) Power (effective) Power (indicated) Efficiency Weight Wire Resistance Steering Ratio Volumetric Efficiency Air Ratio Venturi Air Resistance Parallel Circuit Planetary Gearbox Percent Rectangle Rectangle Column Friction Force Tyre Calculation Serial Circuit Rolling Resistance Cam Dwell Dwell Period Slip Spread of Gears Climbing Resistance Ratio Circumference speed Conversions Not Coaxial Gearbox Valve Opening Area Valve Opening Angle Valve Opening Period Compression Ratio 1 Compression Ratio 2 Amount of Heat Resistance Efficiency Cube Ignition Interval Cylinder
The stroke length is compared with the bore diameter. This stroke-bore ratio has an influence on the operational behaviour of the engine. Whereas the short-stroke engine (left picture) has less stroke than bore, with the long-stroke engine this is (right picture) the other way around. If bore and stroke are approximately the same, one then speaks of an over-square engine.
Whereas long-stroke engines provide more torque in the lower RPM range, short-stroke engines are more capable of particularly high revs and large valve openings. An extreme example is the current (2007) Formula 1 engine being a 2,4 Liter-V8 and with about 98 mm of bore and a 40 mm stroke-length.The latter ensures the fact that the average piston speed, despite the maximum RPM of 19.000 1/min, does not increase the average piston speed much more than 25 m/s. In order to keep the weight of the pistons low, there is no oil ring, almost no piston shaft and a gudgeon pin, which is much shorter and found directly under the piston crown.
