Whats the difference between an SOHC and a DOHC engine?
C Praveen Kumar, via email SOHC stands for Single Over Head Camshaft, DOHC stands for Double Over Head Camshaft. Camshafts are long rods/shafts on top of the cylinder, which open and close valves (gates which allow the entry and exit of the fuel-air mixture and exhaust gases into the cylinder.) Double cams are more effective than single cams, as they allow more valves to run on each cylinder aiding induction and exhaust, increasing power output on the same engine capacity. A typical SOHC engine will have one or two intake valves and one exhaust valve; a DOHC one can have up to three intake and two exhaust valves. However, a DOHC engine, with more and smaller mechanical parts, is normally a bit noisier. I currently own a Maruti 800 and am keen to upgrade to a new car of around Rs 6-7 lakh. It shoul accommodate five people comfortably with good rear seat legroom and plenty of luggage space. I want good ride and handling. My daily drive is around 30 km with about 70 per cent in the city.
