A power transfer assembly (2000) for transferring energy within a combustion engine (1010) externally of the engine. The power transfer assembly includes a crankshaft (2006) adapted to convert reciprocating motion to rotating motion. The power transfer assembly further includes an outdrive (2004, 2020, and/or 2026) adapted to transfer the rotating motion of the crankshaft: to an external device requiring power. The outdrive is non-rigidly interfaced with the outdrive such that the crankshaft is permitted to freely rotate relative to the outdrive about at least one axis (2014) and freely move linearly in at least one direction (2027) relative to the outdrive during operation.