When I did my engineering thesis (1990), it was on intake manifold air and fuel flow, and the development of a test rig for measuring flow, swirl, and tumble in cylinder heads. (only got the design for the latter, but great insights on the former, including that CRC system 1 fuel cleaner was the only cleaner that would get the deposits out of the injectors after a guy the year before ran methanol though the rig.).
The design had to accomodate the J-Car engine in multiple two and 4 valve variants, a DFV head, and the Uni had access to Arthur Bishop's then current experimental rotary valve heads - Aurhtur Bishop, he's the bloke who invented variable ratio Rack and Pinion steering (he had a great induction heat treat furnace, where the rack was measured with optices, and the heat treat altered to increase the case thickness in places to correct emergent bending.
Anyway, he was developing a rotary valve head for the J Car, and I got to see the single cylinder version (on a Kawasaki engine) on the dyno.
Had a LOT of advantages in creating stratified charges, much better opening and closing ramps available etc.
Used a lot of materials that weren't available in the 50s, and would be familiar with people working on mechanical seals.
Very low bonnet (hood) height as well.
Edit...to add additional information...
A rotary valve for an internal combustion engine having a hollow cylindrical rotor having along its bore an inclined integral baffle with ports on either side of the baffle arranged to be brought into communication with a window as the hollow cylindrical rotor rotates, the rotor being supported...
patents.google.com