ORIGINAL: pe reivers
How then is the scavenge pumping done in a 180° "V" engine
The V-engine typical has 90° bank angles or less. Nearing 180°, it's called opposed cylinders. When cylinder pairs have the pistons moving out and in simultaneously, it is called a boxer. The two stroke principle needs to be a boxer when cylinders are at 180°. A 70° or less angled bank also can work as a two stroke. All opposed cylinder engines were 4-stroke engines.
Well thats what I realised after some much needed sleep
All that talk of 180 V, 15 degree 5Cylinder V engines and "W" 12's at 1am in the morning gets a head spinning. All 4 strokes of course.