drove the car maybe 10 miles. Warmed it up as usual so it hadnt even been on boost. Stopped for fuel (V power of course) and when I wen to start the car it wouldnt start which was odd. Had to give give it a bit of throttle and crank it a while the second time then it started. Idled but didnt sound normal. Drove out of the garage and immediately could tell it had no power and was back firing alot. Pulled over and had it recovered back to my workshop. Did the basic checks then took the rocker cover off. Number 3 exhaust valve wasnt opening. Took the rocker arms off of cylinder 3 and the exhaust follower wouldnt come out of its bore. Unscrewed the top of the lifter and could see straight down onto the cam. The remains of the lifter are stuck in the bore but the base of it is completely gone and there are bits of it floating around the top end.