Compression Ratio
Calculate geometric compression ratio from swept and clearance volumes.
How to use
- Enter swept volume.
- Enter clearance volume greater than zero and calculate.
Capabilities and scope
It divides total bottom-dead-centre volume by clearance volume at top dead centre.
How it works
CR=(swept+clearance)/clearance.
Example
Swept 450 and clearance 50 give 10:1.
Useful for
- Calculate geometric engine compression ratio
- Study how chamber volume changes compression ratio
Before you use it
- Dynamic compression, valve timing, and actual cylinder pressure are not included.
Frequently asked questions
Which volume unit should I use?
Any common unit works if both volumes use the same unit.