My '83' Honda 650 Nighthawk had hydraulic lifters! They were tiny, and at the end of a floating rocker arm. Imagine the rocker arm with the valve at one end the lifter at the other and the cam in the middle. The lifter didn't move. I thought it was a strange setup, but it worked well. Sometimes I'd hear a little ticking on startup, but it would quiet down as oil pressure built.
Best part is NOT adjusting 16 valves!