Another fun subject is harmonic vibration and balance. Certain configurations require things like balance shafts and harmonic balancers (arguably unnecessary fluff) to offset the intense vibration, and modifying your engine can result in it self-destructing if this isn't taken into account. Inline and flat 6's and 12's are the best balanced, though the inline is more efficient and requires less maintenance than the flat.
other notable omission are: the 2 stroke engine (commonly found in 2 wheel urban vehicle now these days) and the Miller cycle that was used in the Mazda Xedos 9.
http://en.wikipedia.org/wiki/Category:Piston_engine_configur...
http://www.caranddriver.com/features/the-physics-of-engine-c...
Another fun subject is harmonic vibration and balance. Certain configurations require things like balance shafts and harmonic balancers (arguably unnecessary fluff) to offset the intense vibration, and modifying your engine can result in it self-destructing if this isn't taken into account. Inline and flat 6's and 12's are the best balanced, though the inline is more efficient and requires less maintenance than the flat.
http://en.wikipedia.org/wiki/V6_engine#Balance_and_smoothnes...
http://www.physicsforums.com/showthread.php?t=509340