V-type internal combustion engine

An engine comprising

• at least one pair of cylinders including a first cylinder and a second cylinder, each said pair of cylinders being arranged in a V having an included angle .alpha.;
• a crank including at least a pair of nonaligned crankpins, a first crankpin of each said pair being positioned and arranged for use with said first cylinder and a second crankpin of each said pair being positioned and arranged for use with said second cylinder, said second crankpin being arranged on said crank at an angle .beta. from said first crankpin as measured in a first direction about said crank substantially equal to 180 less than twice said included angle .alpha. of said pair of cylinders;
• a reciprocating mass including a piston and connecting rod for each of said cylinders and crankpins, each said connecting rod being connected at a first end to said piston and at a second end to said crankpin for each of sayd cylinders;
• a balance weight attached to said crank, said balance weight being attached at a balance angle .delta. measured in said first direction about said crank from said first crankpin whose tangent is substantially equal to U/V where
• U=1+cos (.beta.-.alpha.) cos .alpha.-sin (.beta.-.alpha.).multidot.sin
• V=cos (.beta.-.alpha.) sin .alpha.+sin (.beta.-.alpha.).multidot.cos .alpha.,
• said balance weight being mounted at an equivalent radius to said crankpins and being equal in weight to substantially one-half the weight of one of said reciprocating masses multiplied by the square root of the sum of the squares of U and V.