Crankshaft counterweights are required on certain engine configurations to allow the engine to run without excessive rocking couples; cruciform V8 crankshafts are an example of this. Other engine configurations can run happily without counterweighting of any type to eliminate rocking couples, but they often require some counterweighting in order to maintain bearing loads within reasonable limits. Bearing loads not only have affect engine reliability, but also on friction. Some engineers...
Although there are a great many race engines that carry over the stock crankshaft from the production engine on which the competition unit is based, many will choose to replace the production crankshaft with something more accurate and better engineered. Where there are changes to the production engine stroke, or where a bespoke race engine is concerned, there are rarely production car options, so a specifically designed part is required. In the vast majority of cases, racing crankshafts...
In previous articles on oil drillings, nose-fed oil galleries have been discussed. This is not a new concept. However, the drillings used in a modern race engine with significant main bearing/crankpin overlap are far removed from those used in the comparatively long-stroke crankshafts without overlap. For a recent article on crankshafts for Race Engine Technology magazine, crankshaft suppliers revealed that the proportion of their racing crankshaft business which has nose-fed oil galleries...
While there are reciprocating engines that don't have a crankshaft, these are rare and have generally done little to convince people that we ought to abandon it. The crankshaft, with its eccentric crankpins, is not a straightforward part to make. Evidence for this lies in the small number of manufacturers capable of making top-quality examples. Traditionally, the work involved in producing the basic functional shape of such parts has been done on the lathe. We can imagine taking a...
In terms of controlling the axial position and axial float (in a direction parallel to the crankshaft axis) of the con rod, there are two main methods of achieving this - crank-guided rods and piston-guided rods. As you may discern from the descriptions, the first type thrusts against the crankshaft, the second type against the piston. Crank-guided rods remain the most popular type for many kinds of race engine. Commonly, the contact between the crank and rod thrust faces is one of annular...