A standard wet sump engine as found in your 152, chippy and tiger moth will work just as well for inverted/negative flight no problem, you may see a greater loss rate however. Wet sumps just has its oil load slushing around at the bottom of the crankcase (sump) or, if the engine is mounted 'upside down' such as the tiger moth and chipmunk then the oil simply sits around the pistons and exposed cylinder.
Stellair, sorry old chap but that stuff reagarding the Gipsy is bollox. A Chippy or Tiger's Gipsy major is dry sump with a seperate oil tank. A moments thought will tell you that an inverted engine cannot possibly be wet sump. Unless someone's invented anti-gravoty oil (or are you suggesting the entire engine's oil capacity sits in the rocker covers??).
It's not an inverted system, however, since the oil is drawn from the bottom of the tank by the oil pump. So when the tank is inverted, the pump draws air, not oil. That's why it's important with a Gipsy to close the throttle if the engine dies under negative 'g', otherwise on restoration of positive 'g' it will burst into high-power life with not much oil in the bearings.
The reason for a moths engine being 'upside down' is not to provide the pilot forward vision (sorry, shaggy sheep driver) that just happens to be a nice side effect. It is because the aircraft is a taildragger and mounting the engine in the conventional sense would mean a smaller prop would be required to prevent contact with the ground upon raising the tail on take off.
Wrong again
Stellair. As I stated, the reason is to put the propellor thrust line in the right place. It's the extra ground clearance for the prop that's the nice side effect, though neither the Chippy or Tiger's props come anywhere near close to the ground with the tail up, so that isn't an issue.
Having put the thrust line where it needs to be, the cylinders would indeed block the pilot's view (look at some early Moths), so the designer made use of the space available below the thrust line and inverted the engine.
SSD