Motorblocket

Motorblocket, or engine block, is the main structure of an internal combustion engine. It houses the cylinders and often the crankshaft, and provides mounting points for the cylinder head, oil pan, and other subsystems. The block also contains passages for cooling water and oil, enabling heat management and lubrication essential to operation.

Blocks are typically cast from iron or aluminum alloy. Iron blocks are strong and wear-resistant; aluminum blocks are lighter and dissipate heat more quickly. Aluminum blocks often use iron sleeves or plated liners for bore wear. Manufacturing begins with casting, followed by precision machining to achieve bore, deck, and tolerance specifications.

Engine blocks vary by cylinder arrangement (inline, V, flat), number of cylinders, bore and stroke, deck height, and cooling design. Inline fours and sixes are common; V-configurations are used for larger engines. Some blocks use wet sleeves, others dry sleeves or integral liners. Many modern blocks include dedicated oil jets and reinforced ribs for strength.

Function and maintenance: The block provides structural support and alignment for the moving parts and serves as a fluid conduit system. Cracks, core shifts, overheating, or improper torquing can compromise integrity; head-gasket failures can damage the block surface. Inspections include dye-penetrant testing, magnetic particle testing, and pressure testing; monitoring for coolant or oil leaks is routine.

Context and evolution: Historically, cast-iron blocks dominated, with aluminum becoming common in light-weight engines. Modern blocks balance weight, strength, and cooling capacity, and are used across automotive, marine, and industrial applications. Performance builds may employ sleeved blocks, reinforced cores, or special coatings to improve durability under higher power and heat.