Pushrod Engine

The pushrod engine, or overhead valve (OHV) engine, is a type of automobile engine where the valves are opened and closed by a pushrod. This contrasts with overhead cam (OHC), another popular design.

The advantages of the pushrod engine are that it has a less elaborate drive system without long lengths of belts, and it also can be packaged in a smaller space, allowing for more compact car designs, lower hoods, better visibility, and lower center of gravity. A pushrod engine also has nice low end torque usually when compared with an equivalent OHC design. The disadvantages are that it cannot rev quite as fast due to the heavier valve actuating machinery, and it is harder to have multiple valves on the top of the cylinder, which limits how easy it is to control fuel-air mixing. Another disadvantage is that pushrod engines tend to have higher displacement, and in countries where engines are taxed and regulated by displacement, they tend to be unfairly taxed based on displacement rather than the actual amount of pollution they produce. Addionally, foreign car marketers have successfully spread the idea that OHC designs are somehow more high-tech, despite not being any newer or better for most applications.

Pushrod engines are popular in the United States. General Motors produces the 3800 Engine and the LS7 Corvette Engine ?. Chrysler produces the Hemi Engine ?.

Historically the Oldsmobile Rocket V8 ?, first produced in 1949, was a landmark design.