CNN reports that NTSB are now saying that JAL separation only 1 min 45 secs. Extract from CNN below:
"A Japan Airlines flight was cleared for takeoff about two minutes and 20 seconds before the American Airlines flight, but it actually took off one minute and 45 seconds ahead of Flight 587, National Transportation Safety Board Chairman Marion Blakey said Wednesday.
Blakey said preliminary analysis of the flight paths of both planes showed that the JAL flight was about four nautical miles out from the American Airlines flight and traveling 800 feet higher. Wind conditions at the time of Flight 587's takeoff, she said, were "consistent with a wake vortex encounter".
We do not know if this really contributed in any way to the actual accident, but we are looking at it very closely," Blakey said."