checking compression with engine out of car

[e30serg]

So-how can it be done? Pull out all plugs, install compression checker, turn crank by hand with long bar and large socket on crank bolt? I guess that would work...

[trent]

no you need to build pressure faster

put a starter on the engine and fire it with a battery

[Mr.SWISS]

Maybe an impact on the crank if you have a good compressor.

[equate975]

Hit the starter terminals with a battery?

[gazellebeigem3]

better make sure that bitch is secure, or theres gonna be some movement!

[Addissimo]

take a nylon strap and secure it to something, then wire up the battery correctly to a battery, or just terminals, then wire a switch from walmart or something as the solenoid engagement.

[BigD]

How much should you expect the compression figures to vary between having the engine out of the car (cold) and after warming it up inside the car to operating temperature?