turn v-12 pos. grnd. with a 12 volt batt. for a compression test

[charlie1942lc]

i do not currently have a 6 volt battery, and no need to purchase one at this time, but i do have a spare 12 volt that i would like to use to turn the engine over to do a compression test.  having never tried this before i want to be sure not to do any damage. if anyone has done this before i would like to hear from you. also i know the engine will turn when pushed in gear. thanks in advance for any help.

[abelincoln]

Starter likes 12 volts just fine.  I disconnected the car electrics from the starter relay, and ran about a two ohm large (50 amp) resistor in series with the ignition circuit.  To avoid coil damage, check voltage at the points when running, should be 2-3 volts.  Resistor still got hot, but engine ran on 12 volts.