DOHC (Double Over Head Camshaft)

DOHC

DOHC or double overhead camshaft engines are very popular now in all brands of cars. They used to be considered special and used mostly in pricey foreign cars. Most of the time a DOHC engine is a V-6, although V-8 models are starting to find themselves nestled in the engine compartments of the larger American cars and Foreign luxury cars.

The basis of DOHC engines comes from the fact that they make more horsepower because they are more efficient. In general the DOHC engine is used more than ever now, because the trend is to have smaller cars with engines that make lots of power and get good fuel mileage..

A double overhead camshaft engine succeeds the trusty pushrod engine. Pushrod engines have been in use for 100 years plus. It is the original valve train setup. Pushrod engines can be made to produce plenty of power. Nascarengines have pusrods and they make incredible amounts of power. The reality is it cost less for the factory to manufacture the DOHC engines and put them into cars on the assembly line than spice up a pushrod engine. It is what the future is bringing us.

Briefly, in a DOHC engine there is one camshaft per row of cylinders. If the engine is not a V-6 or V-8 it can’t be DOHC. If there is just one row of cylinders it has to be a single overhead camshaft engine (SOHC). Just because it does not have pushrods does not make it simpler. In reality they are more complicated and expensive to fix than a pushrod engine. Most of the DOHC and SOHC engines use a timing belt or chain to operate the camshafts.

I wish to discuss pushrod and SOHC engines in the GotEngines.com Blog. Becoming an educated consumer is of prime importance in making engine replacement decisions. We have a bunch of good information on our blog and it grows everyday.