Is valve rotation encouraged in air-cooled engines powered by LP/propane gas?

In air-cooled engines powered by LP (liquid propane) gas, valve rotation is generally discouraged due to the nature of such engines and the combustion characteristics of propane. Propane has a different combustion process compared to gasoline, which can lead to specific valve wear and performance issues if valve rotation occurs.

In many cases, the design of the engine and the materials used in the valve train are such that excessive rotation can lead to accelerated wear. Maintaining the integrity of the engine's cycle is crucial for optimal performance and longevity. Thus, it is preferable to adhere to standard practices that minimize unnecessary valve movement, ensuring reliability and efficiency in operation.

Some of the other options imply conditions or situations where valve rotation would be acceptable, but none of those are typically valid for standard air-cooled engines operating with propane. The technical consensus is that discouraging valve rotation helps maintain engine health and efficiency in this context.