GA pilot reported while in the left downwind of runway they had near midair collision with another aircraft within 100 feet of their right wing. The pilot took evasive action to avoid a collision.

Narrative

Day 0 around XA:00. Myself (non flying pilot) sitting in the right seat of Aircraft X and a colleague; (flying pilot) in the left seat were established in the left downwind of Runway 32 at Winchester OKV when a Aircraft Y almost caused a mid air collision with us. We were about mid field downwind at traffic pattern altitude when Aircraft Y came out within 100 feet of our right wind tip; climbing and overtaking us. No radio calls were made by Aircraft Y. The flying pilot then made an immediate left 360 to avoid Aircraft Y. This aircraft was so close to us that I could see the whites of his eyes. After looking at his ADS-B track; its clear that he had taken departed Runway 32 after our touch and go and on his departure he made his left crosswind turn before the end of the departure end of 32 and continued his climb into the downwind; nearly colliding with us. We had made all of our pattern position reports. No radio calls were made by Aircraft Y. This pilot is not safe and should not be flying.