Instructor Pilot reported a loss of oil pressure and the appearance of smoke in the cockpit while in the pattern during a training flight. The instructor immediately landed the aircraft and evacuated on the taxiway.

Narrative

A training flight was being conducted with a student in the traffic pattern at ZZZ. A sudden loss of oil pressure occurred and smoke filled the cockpit while turning crosswind in the traffic pattern. Aircraft made it back to the active runway; no injuries. No damage to the aircraft other than to the engine; and no emergency was declared. I recount hearing a 'swooshing' sound; and oil pressure went to 0 PSI and smoke filled the cockpit at about 1;100 ft. MSL as a student and myself were turning crosswind on Runway XX at ZZZ. Oil exploded all over fuselage and windshield. We opened all windows and air vents to help ventilate the cabin. I was able to maintain my altitude but I felt that total engine failure may be imminent. I made my student arm the fire extinguisher. We landed on Runway XX and were able to exit the runway before evacuating the aircraft at XX intersection. We shut down and had ramp workers tow it to the ramp. No injuries occurred. No assistance was needed from ATC. Upon post flight inspection I noticed a crack in the engine block inside the left side engine cowl opening. The engine was still running when we landed. No injuries occurred. No fire occurred. No airframe damage occurred.