Abstract: An internal-combustion engine has a camshaft drive in which the outlet camshaft driven by the crankshaft drives the inlet camshaft via a chain. For the tensioning of the chain, two hydraulic pistons are pressed in opposite directions with respect to one another against the loose end and the load end of the interior side of the chain. For adjustment of the relative camshaft rotating position, the unit consisting of the hydraulic piston and the chain is shifted transversely to the camshafts so that the loose end is shortened and the load end is lengthened, or vice versa.

Abstract: Problems associated with warm engine starting of spark-ignition internal combustion engines with continuous injection into the intake manifold and fuel injection systems of the type utilizing a measuring element and a deliberately operable power control element connected in series, the measuring element being moved as a function of the air volume through-put so as to displace a fuel valve disposed in a fuel supply line for metering a volume of fuel which is proportional to the air volume and which has a warmup control connected by a control pressure line with the fuel valve and a zero-pressure fuel return line with a fuel tank for enriching the fuel-air mixture during the warmup of the internal combustion engine are avoided according to the present invention by an improvement comprising a bypass line interconnecting the control pressure line of the fuel pressure line in bypassing relationship with respect to the warmup control.