Electric solenoid engine the second

My second solenoid engine, built from odds and ends in the shed. An orange LED provides “simulated combustion“, and this one uses a relay to switch the magnet on and off to take the solenoid current away from the slip ring. The slip ring and contacts just switch the relay on and off. The engine runs faster because of this, with a max speed of approx 1,060 rpm measured with a digital tachometer. Runs on 12v DC