Complex sentence: A W8 engine is an eight cylinder piston internal combustion engine in a W configuration, or two imaginary 15 degree VR4 engine blocks, mounted juxtaposed at 72 degrees to one another and coupled to one crankshaft.
Split into simpler sentences: A W8 engine is an eight-cylinder piston internal combustion engine in a W configuration. The W8 can be imagined as flat plane crank V8 engine combining two narrow-angle (15 degree) V4 engine blocks, mounted juxtaposed at 72 degrees to one another and coupled to one crankshaft.