For that matter, VW even experimented with oval bores in the 1.6 NA diesel, to get a 2.3 NA diesel (which might be what you're referring to. The idea was to avoid having to get a turbo, while still fitting in a Golf, because a turbodiesel was EXPENSIVE back then - apparently, an 83 Rabbit Diesel was around $7k, an 83 Rabbit Turbodiesel was around $11k.)
(Side note: They decided that was a bad idea due to wear issues, IIRC, so they then decided to rip off Lancia's narrow-angle V4 design, to fit a 2.3L V6 diesel into a Golf. They had problems with the combination of the long exhaust runners, and the IDI prechambers heating the head too much... so the 2.3L narrow-angle V6 diesel became a 2.4L narrow-angle V6 gas engine, and then became the 2.8L VR6.)