1. Valve Location: The main difference between OHV and side valve engines lies in the location of the valves. In an OHV engine, the valves are located at the top of the cylinder head. The camshaft, which controls the opening and closing of the valves, is also located at the top of the engine. In contrast, in a side valve engine, the valves are located on the side of the cylinder block, with the camshaft located at the bottom.
2. Design and Complexity: OHV engines are generally more complex in design compared to side valve engines. The overhead arrangement of valves and the need for a camshaft and valve train result in more moving parts. Side valve engines, on the other hand, have a simpler design, with the valves directly operated by the camshaft without the need for additional valvetrain components.
3. Performance and Efficiency: OHV engines are generally considered to be more efficient and powerful than side valve engines. This is because the overhead valve design allows for better airflow and combustion, resulting in improved fuel efficiency and power output. Side valve engines, on the other hand, are typically less efficient and have lower power output due to the limitations imposed by the valve arrangement and the shorter distance between the valves and the piston.
4. Noise and Vibration: OHV engines tend to be quieter and produce less vibration compared to side valve engines. This is due to the improved design and the use of modern technologies such as hydraulic lifters and balancer shafts in OHV engines. Side valve engines, on the other hand, can produce more noise and vibration as they have a simpler design with less advanced noise reduction techniques.
5. Maintenance and Accessibility: OHV engines are typically more complex to maintain and require regular adjustments and maintenance tasks such as valve adjustments and camshaft maintenance. Side valve engines, on the other hand, are simpler to maintain and require less frequent adjustments and maintenance as they have fewer complex components.
Overall, OHV engines offer improved performance, efficiency, and reduced noise and vibration, but are more complex and require more maintenance compared to side valve engines. The choice between an OHV and a side valve engine in a lawn mower depends on individual needs and preferences, considering factors such as performance requirements, budget, and maintenance capabilities.
