Tetramand Engine Blocks are devices that are created by the Tetramands and are reputed to be the best in the galaxy.
Since Tetramand Engine Blocks are made from pressure-forged Infinitum, they are able to withstand high amounts of physical force and temperatures and still continue to function. As such, they are considered to be virtually indestructible.
Depending on what the engine is to be used for, the engine block can be any size, shape and form. In Kevin's case, his car's engine was made by the Tetramands, and therefore has been able to continue functioning, despite all the damage it constantly receives.
Due to the reputation the engine blocks have throughout the galaxy, they are considered to be extremely valuable.