An outer body for a rotary engine comprising: two axially spaced apart end walls; a peripheral wall extending between the end walls and defining an internal cavity therewith for receiving a rotor therein; an insert in the peripheral wall of the outer body, the insert having a subchamber defined therein in communication with the cavity; the outer body further having: a pilot injector hole defined therethrough in communication with the subchamber and sized to receive a pilot fuel injector, and a main fuel injector hole defined therethrough in communication with the cavity, spaced apart from the insert and sized to receive a main fuel injector; and an ignition element (84;184;284;384;484) received in the insert in communication with the subchamber, characterised in that: the ignition element extends into an element cavity defined through the insert adjacent the subchamber, a portion (86;186) of the ignition element (84;184;284;384;484) being in communication with the subchamber through an opening (64;164) defined in the insert between the element cavity and the subchamber, the opening (64;164) having a cross-section smaller than a corresponding cross-section of the portion (86;186) of the element (84;184;284;384;484) extending adjacent the opening (64;164) such as to prevent the portion (86;186) from completely passing through the opening (64;164). two axially spaced apart end walls; a peripheral wall extending between the end walls and defining an internal cavity therewith for receiving a rotor therein; an insert in the peripheral wall of the outer body, the insert having a subchamber defined therein in communication with the cavity; the outer body further having: a pilot injector hole defined therethrough in communication with the subchamber and sized to receive a pilot fuel injector, and a main fuel injector hole defined therethrough in communication with the cavity, spaced apart from the insert and sized to receive a main fuel injector; and a pilot injector hole defined therethrough in communication with the subchamber and sized to receive a pilot fuel injector, and a main fuel injector hole defined therethrough in communication with the cavity, spaced apart from the insert and sized to receive a main fuel injector; and an ignition element (84;184;284;384;484) received in the insert in communication with the subchamber, characterised in that: the ignition element extends into an element cavity defined through the insert adjacent the subchamber, a portion (86;186) of the ignition element (84;184;284;384;484) being in communication with the subchamber through an opening (64;164) defined in the insert between the element cavity and the subchamber, the opening (64;164) having a cross-section smaller than a corresponding cross-section of the portion (86;186) of the element (84;184;284;384;484) extending adjacent the opening (64;164) such as to prevent the portion (86;186) from completely passing through the opening (64;164). the ignition element extends into an element cavity defined through the insert adjacent the subchamber, a portion (86;186) of the ignition element (84;184;284;384;484) being in communication with the subchamber through an opening (64;164) defined in the insert between the element cavity and the subchamber, the opening (64;164) having a cross-section smaller than a corresponding cross-section of the portion (86;186) of the element (84;184;284;384;484) extending adjacent the opening (64;164) such as to prevent the portion (86;186) from completely passing through the opening (64;164).