Enter the bore diameter, stroke length, and number of cylinders into the calculator to determine the cranking pressure of an engine. This calculator helps in estimating the pressure exerted by the pistons during the cranking phase of an engine’s operation.
Cranking Pressure Formula
The following formula is used to calculate the cranking pressure.
CP = (BD^2 * SL * CN * 0.7854)
Variables:
- CP is the cranking pressure (PSI)
- BD is the bore diameter (inches)
- SL is the stroke length (inches)
- CN is the number of cylinders
To calculate the cranking pressure, square the bore diameter, multiply by the stroke length and the number of cylinders, and then multiply by 0.7854.
What is Cranking Pressure?
Cranking pressure is the pressure generated inside an engine’s cylinders when the engine is being cranked by the starter motor before it starts running. It is an important parameter for diagnosing engine health and performance. Higher cranking pressures generally indicate good sealing and compression within the engine’s cylinders, which is critical for efficient engine operation.
How to Calculate Cranking Pressure?
The following steps outline how to calculate the Cranking Pressure.
- First, measure the bore diameter (BD) in inches.
- Next, measure the stroke length (SL) in inches.
- Determine the number of cylinders (CN) in the engine.
- Use the formula CP = (BD^2 * SL * CN * 0.7854) to calculate the cranking pressure.
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
bore diameter (BD) = 4 inches
stroke length (SL) = 3.5 inches
number of cylinders (CN) = 6
Using the formula, the cranking pressure (CP) is calculated as:
CP = (4^2 * 3.5 * 6 * 0.7854) = 351.03 PSI
