Brought home a 1956. 235 engine. Put a little oil in spark plug holes waited awhile. With plugs out engine turned over well by hand. Valves opened and closed. With everything ready I hooked up jumper cables and tried to fire it up. It turned very slow. Not enough to start. Would turn two times and stop. Took plugs out and it turned over great. Do I need a battery and not jumper cables? Is there something wrong with starter? What should I check?