My guide to engine break-in for a freshly rebuilt classic V8, based on doing this six times.

Change the oil before the first start. Use a break-in oil with high zinc content — ZDDP is critical for flat-tappet camshafts. Pre-lube the engine by cranking with the coil wire disconnected until you see oil pressure.

First start: run it at 2,000 to 2,500 rpm for the first 20 minutes to seat the rings. Vary the rpm slightly. Let it cool completely, check for leaks, change the oil again. First drive should be varied throttle and rpm — no cruising at constant speed for the first 500 miles. Hard acceleration and engine braking are fine and actually help ring seating.

Third oil change at 500 miles, then switch to your regular oil.