Ok, so I have a 1940 model buick straight 8 engine I bought as a spare. Motor is complete. I have two separate starters. I am trying eitjier starter with 12 volts, no other vehicle electronics hooked up. From what I read the starter can handle the 12 no issues. When I try these starters outside of the vehicle (testing with jumper cables) they function flawlessly. When on the car both starters will barley crank the engine when the bendix is engaged. I thought maybe the engine may be tight or trying to lock up, but the engine has no belts currently and can be turned by hand fairly easily. Thanks!