The PB came with a engine less than 1L (900 something CC), no syncromesh on any of the gears and a Bishop cam steering like on the TCs. The engine was an osingle verhead cam with the cam driven through a set of right angle gears, driven by a verticaly mounted generator at teh front of the engine, driven in turn by another set of right angle gears off of the crank. There was no fan or water pump, it was cooled completely by thermosyphon circulation of the coolant, which was surprisingly efficient. It had no speedometer, the tachometer (which was a chronometric, which means it used a clock work internally and the needle anvanced and cam back down in descrete increments) and was calibrated in RPM on the inner ring, MPH in third on the second ring and MPH in top gear on the outside ring. The frame and body was flexable beyond all belief, to the point that you could feel it flexing when you went around corners. With the sloppy Bishop cam steering, if you went ove railroad tracks at speed, it was anybody's guess which way the car would dart off when the front wheels came back down on the ground. We had on for a couple of years and yes, it was not a real good daily driver. The 0-60 times could be measured in fortnights and the suspension was like riding on 2x4s. With no syncromesh, I soon learned that it was as easy to shift without grinding gears without using the clutch as when you did. As a result I only used the clutch to start out and to stop. I drove it from Seattle to Los Angles for a GoF West in 76 and that was a real experience. All that aside, I still feel that it is one of the prettiest cars that MG ever made.
Cheers