Search results
Results from the WOW.Com Content Network
In an OHV engine the camshaft at the bottom of the engine pushes the pushrod upwards. The top of the pushrod presses upwards on one side of the rocker arm located at the top of the engine, which causes the rocker arm to pivot. This motion causes its other end to press downwards on the top of the valve, opening it.
Although an overhead camshaft (OHC) engine also has overhead valves, the common usage of the term "overhead valve engine" is limited to engines where the camshaft is located in the engine block. In these traditional OHV engines, the motion of the camshaft is transferred using pushrods (hence the term "pushrod engine") and rocker arms to operate ...
This reduced inertia in OHC engines results in less valve float at higher engine speeds (RPM). [1] A downside is that the system used to drive the camshaft (usually a timing chain in modern engines) is more complex in an OHC engine, such as the 4-chain valvetrain of the Audi 3.2 or the 2 meter chain on Ford cammers. Another disadvantage of OHC ...
On most overhead valve (OHV) engines, proper clearance between the camshaft and tappet is achieved by turning a set screw in the end of the rocker arm that contacts the end of the pushrod until a desired gap is achieved using a feeler gauge. Too large a gap results in wear from misaligned parts and compromised engine performance, and too small ...
Pushrods are long, slender metal rods that are used in overhead valve engines to transfer motion from the camshaft (located in the engine block) to the valves (located in the cylinder head). The bottom end of a pushrod is fitted with a lifter, upon which the camshaft makes contact. The camshaft lobe moves the lifter upwards, which moves the ...
A single camshaft located in the engine block uses pushrods and rocker arms to actuate all the valves. OHV engines are typically more compact than equivalent OHC engines, and fewer parts mean cheaper production, but they have largely been replaced by OHC designs, except in some American V8 engines.
The Chevrolet Inline-4 engine was one of Chevrolet's first automobile engines, designed by Arthur Mason and introduced in 1913. Chevrolet founder Billy Durant, who previously had owned Buick which had pioneered the overhead valve engine, used the same basic engine design for Chevrolet: exposed pushrods and rocker arms which actuated valves in the detachable crossflow cylinder head.
Though it was designed as a pushrod engine, it was advanced for the time. [1] The pushrod version of the Lancia boxer was only ever used in the Flavia, and its derivatives including the Lancia 2000. In 1976, a new overhead cam engine based on a similar layout was designed and brought into production in 2 and 2.5-litre displacements for the Gamma.