Bore Stroke Ratio

The Bore Stroke Ratio calculator computes the ratio between a cylinder's bore length (b) and its stroke length (s).  

INSTRUCTIONS: Choose units and enter the following:

• (B) Bore of Cylinder
• (S) Stroke Length

Bore Stroke Ratio (BSR): The calculator provides the ratio of the bore (diameter) to the cylinder stroke length. 

The Math / Science

The formula for the bore stroke ratio is:

     BSR = B / S

where:

• BSR = bore stroke ratio
• B = Bore Diameter
• S = Stroke Length of the Piston Travel

Combustion Engine Calculators

Ratios and Lengths

• Cylinder Bore Diameter: Computes the diameter (bore) based on the engine displacement, number of cylinders and the stroke length.
• Bore Stroke Ratio: Computes ratio based on the diameter of the bore and the length of the stroke.
• Combustion Ratio: Computes ratio base on the minimum and maximum displacements of the cylinder at the beginning (1-Induction) and compressed (3-Power) portions of the combustion cycle
• Displacement Ratio: Computes ratio based on the volumes at the beginning and end of the stroke.
• Rod and Stroke Length Ratio: Computes ratio base on the rod and stroke lengths. 
• Stroke Length: Computes the required stroke length based on the total engine displacement, number of cylinders and the bore.
• Piston Position:  Computes the piston position based on the crank angle, crank radius, and rod length.
• Piston Deck Height: Computes deck height based on Block Height, Rod Length, Stroke Length, and Pin Height.

Volumes and Displacements

• Total Volume (displacement) of a Combustion Engine: Computes volume based on the bore, stroke and number of cylinders.
• Volume (displacement) of a Engine Cylinder: Computes volume based on the bore and stroke.
• Volume (displacement) of an Engine with an Overbore: Computes volume based on the stroke, bore, overbore and number of cylinders.
• Equivalent Volume of a Rotary Engine: Estimates rotary engine volume based on the swept volume and number of pistons.
• Carburetor Air Flow: Estimates the volumetric flow of air through a carburetor based on a four-stroke engine's displacement, RPMs, and volumetric efficiency.
• Compressed Volume of a Cylinder: Compute volume when the piston is at the end of the stroke and the chamber is at its smallest (and most compressed) volume, based on the chamber, deck, crevice, chamfer, gasket, valve relief and dome/dish volumes.  This is the second volume (V2) in the Compression Ratio calculation.
• Volume of a Gasket: Computes gasket volume (displacement) based on the inner and outer diameters and the gasket's thickness.
• Volume of a Cylinder Deck: Computes the deck volume based on the deck height and the bore.
• Volume of a Cylinder Crevice: Computes crevice volume based on the piston diameter, cylinder bore and the crevice height.
• Volume of a Cylinder Chamfer: Computes chamfer volume based on the cylinder diameter and the chamfer height and width.
• Clearance Volume of a Piston: Computes the volume remaining in the combustion chamber when the piston is at its top dead center (TDC) which is the space above the piston crown when it's at its highest point in the cylinder.
• Engine Compression Ratio: Computes the ratio of the volume of the combustion chamber with the piston at its bottom dead center (BDC) to the volume with the piston at its top dead center (TDC).

Speeds and RPMs

• Piston Speed (mean): Computes the mean (average) piston speed based on stroke length and RPMs.
• Max Piston Speed: Computes max speed based on stroke length and RPMs
• RPMs: Computes revolutions per minute based on piston speed and stroke length.

Vehicle Calculators

• Approach (Departure) Angle: Computes the maximum angle of a ramp onto which a vehicle can climb without scraping.
• Degree to Percent Grade: Converts a grade to a degree angle.
• Camber angle - Wheel camber (tilt) calculation of angle
• Camber offset - Wheel camber (tilt) calculation of offset
• Breakover Angle: Compute maximum angle that a vehicle can drive over without the ground touching the vehicle's undercarriage.  
• Time to Overtake: Computes the time for one object to overtake another.
• Distance to Overtake: Computes distance traveled to overtake another.
• Speed to Overtake: Computes the average velocity to overtake another.
• Distance Traveled: Computes the distance traveled over a period of time.
• Speed from Skid Marks: Estimates the speed of a vehicle based on length of skid marks.
• Braking Distance: Estimates distance to stop a vehicle based on initial velocity and braking coefficient.
• Total Stopping Distance: Computes the distance to stop a vehicle based on the initial velocity, reaction time and a braking coefficient.
• Speed from the Braking Distance: Estimates the initial speed based on the distance to stop a vehicle and the a braking coefficient.
• Used Car Price Comparison: Estimates the better value between two vehicles based on their mileage, cost and expected lifespan (miles).
• Belt Length: Computes the length of a belt that goes around two pulleys based on the pulley diameters and the distance between the axles.
• Belt Speed: Computes the speed at which a linear length of belt travels around a pulley  based on the diameter of the pulley and the rotation rate.
• Pulley RPMs: Computes the RPMs of a pulley based on the belt speed and diameter of the pulley.
• 2nd Pulley RPMs: Computes the RPMs of a second pulley based on the the RPMs and Diameter of the first pulley and the diameter of the second pulley.
• 2nd Pulley Diameter: Computes the diameter of a second pulley based on the RPMs and diameter of the first pulley and the RPMs of the second pulley.
• RPM of 4th pulley on three shafts: Computes the RPMs (rotation rate) of a pulley when the RPM and Diameters are known for a series of pulleys on three axles.
• 2nd Gear RPM: Calculates the RPMs of a second gear when the RPMs and number of teeth are known for the first gear and the number of teeth of the second gear is known,
• 2nd Gear Torque: Calculates the torque of a second gear when the torque and number of teeth are known for the first gear and the number of teeth of the second gear is known,