Abstract: A counterbalancer for an engine, the counterbalancer having a housing, a first shaft and a second shaft each positioned within the housing such that the first shaft is configured to be rotated by the engine in use. A first gear and a first weight are each non-rotatably coupled to the first shaft and a second gear and a second weight are each non-rotatably coupled to the second shaft. The first gear and the second gear are meshed such that the first weight and the second weight rotate together to counterbalance the engine in use. The counterbalancer further includes roller bearings that rotatably support the first shaft and the second shaft within the housing and retainer clips that prevent axial movement of the bearings within the housing.

Abstract: A marine engine and methods are for making a marine engine having a cylinder block which defines a cylinder bore and a liner disposed in the cylinder bore, the liner being axially elongated and providing a piston running surface. The liner has a first outer diameter surface portion which is axially constrained with respect to with an interior surface of the cylinder block and a second outer diameter surface portion which is axially unconstrained with respect to the interior surface of the cylinder block.

Abstract: A fastening structure for securing two disparate sections of an aluminum silicon alloy product. A precipitation hardenable austenitic stainless steel bolt engages each hole of a first and second aluminum silicon alloy product sections to fasten the sections together. The fastening structure is optimally utilized in a high temperature environment having thermal fluctuations. In such environments, the precipitation hardenable austenitic stainless steel bolt has less than 15% thermal relaxation after thermal fluctuations, and in some embodiments, less than 13% thermal relaxation after thermal fluctuations. The invention is of particular use for the fastening of an engine block crankcase utilized in a high temperature environment having thermal fluctuations where an engine block, a crankcase bedplate and a crankcase cover are formed from AA 362.0 alloy.

Abstract: A marine engine has a crankshaft that rotates about a crankshaft axis; a crankcase supporting the crankshaft, the crankcase being made primarily of a first material; and a cover on the crankcase. The cover includes a heat exchanger having an inner plate facing an interior of the crankcase, and the inner plate is located such that rotation of the crankshaft causes lubricant in the crankcase to impinge upon the inner plate. The cover also includes a frame holding the heat exchanger and isolating the heat exchanger from direct contact with the crankcase. At least a portion of the frame is made of a second material that is more compliant than the first material.

Abstract: A marine engine has a cylinder block defining at least one cylinder bore and a cylinder liner providing a running surface for a piston in the cylinder bore. The cylinder liner is non-axisymmetric relative to a center axis of the cylinder liner. The cylinder block defines a pocket that retains the cylinder liner and prevents the cylinder liner from rotating about the center axis. Novel cylinder liners, assemblies and methods are provided for forming a marine engine having the cylinder block with the cylinder liner formed therein.

Abstract: A marine engine has an intake camshaft, an exhaust camshaft, and a crankshaft. Combustion in the marine engine causes rotation of the crankshaft which in turn causes rotation of the intake camshaft and exhaust camshaft. Rotation of the intake camshaft operates intake valves for controlling inflow of air to the marine engine. Rotation of the exhaust camshaft operates exhaust valves for controlling outflow of exhaust gas from the marine engine. A cam phaser is located at least partially inside at least one of the intake camshaft and the exhaust camshaft and is configured to vary a timing of operation of at least one of the intake valves and exhaust valves.

Abstract: A marine engine has a crankcase containing lubricant; an intake plenum for conveying intake air for combustion in the marine engine; and a cooling apparatus located between the crankcase and the intake plenum. The cooling apparatus is configured to cool both the lubricant in the crankcase and the intake air in the intake plenum.

Abstract: A marine engine has a cylinder block comprising first and second banks of cylinders disposed along a longitudinal axis and extending transversely with respect to each other in a V-shape so as to define a valley there between; and a lubricant cooler located in the valley and extending parallel to the longitudinal axis. The lubricant cooler has a lubricant conduit that conveys engine lubricant parallel to the longitudinal axis and then transversely to the longitudinal axis to the cylinder block. The lubricant cooler further has a cooling conduit that conveys cooling fluid alongside the lubricant conduit to thereby cool the lubricant conduit and the engine lubricant therein.

Abstract: An outboard motor comprises an engine block having vertically-aligned first and second banks of cylinders that extend from each other in a V-shape, a vertically-extending central drain passage located below the first bank of cylinders and being configured to drain lubricant to an underlying sump, a vertically-extending crankshaft, and a central deflector located between the first and second banks of cylinders. The central deflector extends from the engine block towards the crankshaft and being configured to deflect lubricant away from the crankshaft to the central drain passage.

Abstract: A marine engine has a crankcase having a crankshaft that rotates about a vertical crankshaft axis; a cover on the crankcase; and a cooling member disposed in the crankcase. The cooling member has an inner surface that faces the crankshaft and an outer surface that faces the cover. The cooling member is configured such that rotation of the crankshaft causes lubricant in the crankcase to impinge on and drain down both the inner and outer surfaces of the cooling member.

Abstract: A marine engine comprises a cylinder block that defines a cylinder bore; a piston that reciprocates in the cylinder bore under force of combustion in the marine engine; and a liner disposed in the cylinder bore between the piston and the cylinder block. The liner provides a running surface for the piston. The liner has a cylindrical liner body that is sized to fit snugly within the cylinder bore and a pair of diametrically opposing tabs axially extends from liner body into the cylinder bore. Methods of making a marine engine are also disclosed.

Abstract: An outboard marine engine comprises a crankcase; a crankshaft disposed in the crankcase and being rotatable about a crankshaft axis; a crankcase cover on the crankcase, the crankcase cover enclosing the crankshaft in the crankcase; and an air intake plenum that is integrally formed with the crankcase cover. The air intake plenum conveys intake air for combustion in the outboard marine engine.