Some of you may remember that I bought a hot Rebello motor for my early 260z and when I first started it there was a clunking sound. Luckily that problem ended up being a clutch slave cylinder bolt that was too long and it was resolved pretty easily. Since then I put about 200 miles on the new motor and its been reliable. Yesterday I went to my garage to start the car for work and after running for about a minute there was a horrific clunking sound so I shut it down immediately and took the truck to work. Its been cold (for the middle of California) in the low 30's (about 0 Celsius) but in the garage I estimate the temp to be in the mid 40's. After work I took out all of the spark plugs and rotated the motor by hand to see if i could feel/hear any interference and the motor spun nicely. With the spark plugs still removed I cranked the motor with the starter and still everything ran smooth. After consulting with the elders I put new plugs in the car and attempted to start it again, this time on video. As you can see the car starts and runs for about 30 seconds at about 1100 RPM before the noise kicks in. What should I be looking for?