A roots-type blower comprising: a rotor bore housing having a molded, one-piece polymeric construction, the rotor bore housing defining a first rotor bore and a second rotor bore, the rotor bore housing also defining a first bearing pocket corresponding to the first rotor bore and a second bearing pocket corresponding to the second rotor bore, the rotor bore housing further defining a gear chamber; a first bearing mounted within the first bearing pocket and a second bearing mounted within the second bearing pocket; a first roots-type rotor having a first rotor shaft aligned along a first rotor axis and a second roots-type rotor having a second rotor shaft aligned along a second rotor bore axis, the first and second roots-type rotors (76, 78) being respectively positioned within the first and second rotor bores (88, 90), the first and second roots-type rotors being rotatable relative to the rotor bore housing about their respective first and second rotor axes (82, 86), the first and second rotor bore axes (82, 86) being relatively positioned such that the first and second roots-type rotors (76, 78) intermesh with one another when the first and second roots-type rotors (76, 78) are rotated about their respective first and second rotor axes (82, 86), the first rotor shaft being supported by the first bearing and the second rotor shaft being supported by the second bearing; and first and second gears (96, 98) positioned within the gear chamber, the first gear being coupled to the first rotor shaft and the second gear being coupled to the second rotor shaft, the first and second gears (96. 98) intermeshing with one another and being configured for transferring torque between the first and second rotor shafts (80, 84); characterized in that the molded polymeric construction includes a polymeric base material and reinforcing fibers embedded within the base material; and the rotor bore housing includes first and second cylindrical pocket-defining walls that respectively define the first and second bearing pockets (112, 114), wherein the reinforcing fibers are aligned in a circumferential orientation within each of the first and second cylindrical pocket defining walls, wherein the rotor bore housing further includes first and second rotor bore-defining walls that respectively define the first and second rotor bores (88, 90), and wherein the reinforcing fibers within the first and second rotor bore-defining walls are oriented parallel with respect to the first and second rotor bore axes. a rotor bore housing having a molded, one-piece polymeric construction, the rotor bore housing defining a first rotor bore and a second rotor bore, the rotor bore housing also defining a first bearing pocket corresponding to the first rotor bore and a second bearing pocket corresponding to the second rotor bore, the rotor bore housing further defining a gear chamber; a first bearing mounted within the first bearing pocket and a second bearing mounted within the second bearing pocket; a first roots-type rotor having a first rotor shaft aligned along a first rotor axis and a second roots-type rotor having a second rotor shaft aligned along a second rotor bore axis, the first and second roots-type rotors (76, 78) being respectively positioned within the first and second rotor bores (88, 90), the first and second roots-type rotors being rotatable relative to the rotor bore housing about their respective first and second rotor axes (82, 86), the first and second rotor bore axes (82, 86) being relatively positioned such that the first and second roots-type rotors (76, 78) intermesh with one another when the first and second roots-type rotors (76, 78) are rotated about their respective first and second rotor axes (82, 86), the first rotor shaft being supported by the first bearing and the second rotor shaft being supported by the second bearing; and first and second gears (96, 98) positioned within the gear chamber, the first gear being coupled to the first rotor shaft and the second gear being coupled to the second rotor shaft, the first and second gears (96. 98) intermeshing with one another and being configured for transferring torque between the first and second rotor shafts (80, 84); characterized in that the molded polymeric construction includes a polymeric base material and reinforcing fibers embedded within the base material; and the rotor bore housing includes first and second cylindrical pocket-defining walls that respectively define the first and second bearing pockets (112, 114), wherein the reinforcing fibers are aligned in a circumferential orientation within each of the first and second cylindrical pocket defining walls, wherein the rotor bore housing further includes first and second rotor bore-defining walls that respectively define the first and second rotor bores (88, 90), and wherein the reinforcing fibers within the first and second rotor bore-defining walls are oriented parallel with respect to the first and second rotor bore axes.