Well let me take a whack at that question. The California cars were rebuilt and are rated at 125 mph.
https://en.wikipedia.org/wiki/California_Car_%28railcar%29
We are talking about the new alignment so existing stops don't count, only those on the new route. That leaves exactly one stop between Fresno and Bakersfield, the Kings/Tulare Regional Station. The distance on the new right of way is 114 miles from Bakersfield to Fresno. If there were no acceleration/deceleration, speed limits etc. the calculation would be easy: 114/125*60 or about 55 minutes. However adding in a stop in the middle gives you an acceleration from 0 to 125 mph, a deceleration back to zero, a dwell at Kings/Tulare, another acceleration to 125 and a deceleration to zero at Bakersfield. So the simple answer using California Cars and Chargers is no. It can't be done in under an hour. Of course electric high speed trains are another matter.