horizontally opposed boxer type engine: crankshaft in the middle, 2 cylinders, 2 pistons pointing outward. Normal cylinders with a cylinder head at the top.
opposed-piston engine: 2 crankshafts on the ends, 2 pistons share ONE cylinder. No cylinder head, so has to use ports in tthe cylinder wall. Very different.
There were a spate of articles about it around August.Are there any news about the Cummins /Achates ACE (advanced combat engine)? It has been quiet about its development from the companies for two years now ...