Monday, November 11, 2013
DOHC Engine Specifications
The first double overhead camshaft engine was a two valve, and it was made for the Peugeot in 1913. Other early incarnations of the DOHC included the Alfa Romeo (1925), the Maserati (1926) and the Bugatti (1931). The Ford Motor Company first used the DOHC in its Kent (1962), and General Motors first used it in 1975 in its Cosworth 2300.
Design Specifications
The DOHC engine was designed using two separate camshafts mounted above the cylinders. Two camshafts can be found in each cylinder head, and each one controls the intake and exhaust valves. This means that in a DOHC V engine, there are four camshafts -- two for one cylinder head and two for the other.
Camshaft Operation and Spark Plug Location Specifications
In a DOHC engine, the camshaft controls the valves in two ways: directly or by using a short rocker. Camshaft adjustable pulleys can be used in a DOHC engine, which help improve the timing of the opening and closing of the valves. You can also install cams in a DOHC engine that will improve your cam lobe profile because you can moderate the lobe shape easier than in a single overhead camshaft engine. In a DOHC engine the spark plug is placed in the middle of the combustion chamber. Being in the middle improves the combustion efficiency of the engine.
Power Specifications
A DOHC engine is heavier than a single overhead camshaft (SOHC) engine. This means that a 16 valve SOHC engine would have a greater torque than the DOHC engine at low engine speeds. However, when the engine speeds are operating at their maximum, a 16 valve DOHC would have higher peak torque and horsepower levels.
