Auspuffanlage fuer mehrzylindrige Brennkraftmaschinen

804,950. Exhaust-silencers; exhaust pipes; heating charge. VOLKSWAGENWERK G.m.b.H. Oct. 17, 1956 [Oct. 25, 1955(2)], No. 31541/56. Classes 7(2) and 7(3) In an engine having an exhaust silencer 12, Fig. 2, lying behind four cylinders (not shown) arranged in horizontally-opposed pairs, exhaust pipes 1, 3 and 2, 4 respectively from nearer and, further cylinders are of substantially the same total length, the pipes 2, 4 continuing as ducts 17, 18 formed in coacting plates 15, 16, Fig. 3. The pipes 1, 3 discharge downwardly through the plates 15, 16 and the pipes 2, 4 upwardly through cut-outs 19, 20 at the ends of the ducts 17, 18. The duct 17 is narrower than the duct 18 to compensate for exhaust bypassed between connections 10 and 9 for charge heating; in a modification the pipe 17 is shortened instead. In Fig. 4, in which the pipes 1, 3 discharge clear of shortened plates, the connection 9 is dispensed with, a pipe 11 leading from the connection 10 being in heat-interchange relationship with a manifold 20 below a carburetter flange 22 and discharging at 26 into one of two silencer outlets 24 lined with damping material.