An automobile engine replacement is an engine or a major part of one that is sold individually without any other parts required to make a functional car (for example a drivetrain ). These engines are produced either as aftermarket parts or as reproductions of an engine that has gone out of production. Use Types of replacement engines Remanufactured engines (also known as "reconditioned" or "re-engineered") Rebuilt engines Used engines New engines (also known as "crate engines") "Short block" - everything between the cylinder head and the oil pan (excluding those items) "Long block" - a short block, with mounted and gasketed cylinder head, valves and camshaft "Crate engine" - often more than a long block, including intake manifold, and carburetor or fuel injection system, and perhaps an alternator Replacement blocks Terminology Replacement engines are used to replace classic car en...