There are half journal bearings in engines. They are confined to two stroke rods as far as I know. See the early Napier Nomad that had two rods on the same crankpin held together with a pair of thin rings. This was last tried on the Continental experimental diesel of the 1980's that had a couple of whirlly gig balancers on each end of the crank. (Making a flat 4 cylinder engine as long as a six). McCulloch drone engines just had a steel strap at the back of the rod to keep the rod on the crankpin in case of a miss fire.
Roller cam assemblies can get unhappy if the contact angle reaches about 30 degrees. (You mention 40). Things can jam and lock up.
What do I think? I think it looks like a frictional nightmare.