It is a weird mechanism, agreed - I've attached a picture which tries to show the piston coming down later and therefore cylinder pressure being preserved until more leverage is available - happy to have the idea shot down in flames just so long as I can follow why...
A Google trawl uncovered a few avenues that have been explored using an Eccentric bearing on the big end journal which gives the big end of the connecting rod a secondary motion (on top of the simple rotary motion of the crankshaft).
Most have had something to do with Variable Compression Ratio...
