Abstract: A two-stroke, opposed piston, diesel engine is provided herein. The engine includes a thermal shield and a fluid gap which surround the exhaust ports to shield the engine block from an exhaust fluid from the cylinder assembly. Additionally, a cooling fluid is transferred to a plurality of helical shaped passageways which encircles the cylinder housing. These features allow the engine to operate at a cooler temperature and allow for more uniform cooling of the engine. Preferably, the engine also includes a first injector which injects a combustion fluid into the cylinder chamber between the pistons in the same direction as a swirl created within the cylinder chamber. This increases the distribution of the combustion fluid in the cylinder chamber and enhances the efficiency of the engine.