The specific limit to how high an engine can rev before something breaks or malfunctions varies depending on the design and specifications of the engine itself. Modern vehicles and motorcycles are equipped with a range of technologies and materials that have improved their performance and durability compared to older models.
In general, most modern gasoline-powered vehicles and motorcycles have a redline, which is the maximum recommended engine speed specified by the manufacturer. Exceeding the redline for an extended period can put excessive stress on the engine components and potentially lead to damage or failure. Typically, the redline for modern engines is in the range of 6,000 to 8,000 revolutions per minute (RPM) for cars and can be even higher for high-performance sports cars. Motorcycles can have redlines ranging from 10,000 to 15,000 RPM, depending on the make and model.
It's important to note that while the redline indicates the maximum recommended engine speed, it's not advisable to consistently operate at or near that limit. Continuous high-revving can cause increased wear and tear on engine components and reduce the overall lifespan of the engine. It's best to follow the manufacturer's recommendations regarding engine speed and maintenance intervals to ensure optimal performance and longevity.