The number that is important is cranking pressure, measured in pounds per square inch. Privacy Guaranteed - your email is never shared with anyone, opt out any time. Looks like I have alot to research. The CCP will drive the need for compression releases. Cranking Pressure Calculator - Wallace Racing When a pile of material is squished together and made smaller and more dense, this is an example of compression. Throttle position affects the accuracy, also. Repair or replace the problematic part. Changing the rod length will affect the piston location in the bore relative to cam timing everywhere except at TDC and BDC thus changing the dynamics of the engine. If youre shopping for a compression sock without a prescription, you will likely want either the 8-15 mmHg or 15-20 mmHg compression level.