Aspects of the disclosure are directed to a crank. In accordance with one aspect, the crank includes a first web, wherein the first web includes a first plurality of protrusions, and wherein one of the first plurality of protrusions includes a first midline radial axis and is non-symmetric with respect to the first midline radial axis; and a second web coupled to the first web, wherein the second web includes a second plurality of protrusions, and wherein one of the second plurality of protrusions includes a second midline radial axis and is non-symmetric with respect to the second midline radial axis.

Aspects of the disclosure are directed to an engine crank. In accordance with one aspect, the engine crank includes a first web, wherein the first web includes a first plurality of air channels, and a second web coupled to the first web, wherein the second web includes a second plurality of air channels.

Aspects of the disclosure are directed to an engine crank. In accordance with one aspect, the engine crank includes a first web, wherein the first web includes a first plurality of air channels, and a second web coupled to the first web, wherein the second web includes a second plurality of air channels.

A breather device includes: a breather chamber into which oil mist in a crank chamber of a combustion engine is introduced; and a breather passage configured to guide oil mist from a crank chamber into the breather chamber. The breather chamber has formed therein a labyrinth structure in which gas-liquid separation of the oil mist is performed. An introduction pipe forming a part of the breather passage is communicated with an upper portion of the crank chamber, and projects upward from an upper end portion of the crank case.

A breather device includes: a breather chamber into which oil mist in a crank chamber of a combustion engine is introduced; and a breather passage configured to guide oil mist from a crank chamber into the breather chamber. The breather chamber has formed therein a labyrinth structure in which gas-liquid separation of the oil mist is performed. An introduction pipe forming a part of the breather passage is communicated with an upper portion of the crank chamber, and projects upward from an upper end portion of the crank case.

A breather device for a combustion engine includes a breather chamber in which oil mist in the combustion engine is introduced, a breather passage that guides the oil mist to the breather chamber from a crank chamber, and a blowby gas passage that guides, to an air intake passage, blowby gas having been subjected to gas-liquid separation in the breather chamber. A separator is accommodated in a blowby drawing pipe forming the blowby gas passage. The oil mist is made into droplets by the separator so that the liquid component is collected in the breather chamber.

A breather device for a combustion engine includes a breather chamber in which oil mist in the combustion engine is introduced, a breather passage that guides the oil mist to the breather chamber from a crank chamber, and a blowby gas passage that guides, to an air intake passage, blowby gas having been subjected to gas-liquid separation in the breather chamber. A separator is accommodated in a blowby drawing pipe forming the blowby gas passage. The oil mist is made into droplets by the separator so that the liquid component is collected in the breather chamber.