Rotary internal combustion engines

A rotary piston internal combustion engine comprising a housing having a two lobed epitrochoidal bore therethrough, a mainshaft mounted axially within said bore, a rotor of generally equilateral triangular shape mounted on an eccentric journal of the mainshaft for planetary rotation within the bore such that its apices maintain sliding contact with the wall of the bore and thereby form three working chambers which vary in volume as the rotor rotates, said housing having an inlet port leading to said working chambers, means providing axial cooling passages through said rotor, end plates secured to the housing and forming axially spaced end walls closing the bore, a first cooling air induction port in one of the end plates positioned to communicate with said axial cooling passages in the rotor, a second port formed in the outer end plate also positioned to communicate with said axial cooling passages in the rotor, a conduit having a portion external of said engine connecting the second port to said inlet port, air inducted into the working chambers thereby flowing successively through the first port, said rotor cooling passages, the second port and said conduit, a heat exchanger interposed in said external conduit portion so arranged that the induction air flowing through the conduit constitutes substantially the sole heat input to the heat exchanger, said heat exchanger being adapted to dissipate heat from the induction air flowing through said conduit whereby the temperature difference between the induction air flowing through said conduit and ambient air may be reduced, a bypass whereby the induction air flowing through the conduit can bypass the heat exchanger means for selectively opening and closing the bypass passage and means responsive to engine load for operating said bypass passage opening and closing means.