They also tended to have to restart those engines pretty often didn't they? That was only after it was in ram jet mode though if I remember correctly.
Not quite, the 'unstart' event was an automatic recovery in ramjet. If the spike didn't translate correctly and the shock got inside the inlet, there would be a subsonic flow region inside the engine and a massive high pressure associated with it. A great loss of thrust, which is quickly overcome by supersonic flow and a massive restoration to supersonic flow and power. Hence the 'unstart', which wound up translating to the pilot as a massive blow to the side of the head as the aircraft 'lurched' to whichever side the unstart occured.
Pilot's always knew which side had burbed, as that was the same side their head hurt...
Great, middle and high school all over again.
