The Volkswagen Type 2 (also known as the VW Bus or Camper) was originally powered by air-cooled, flat-four engines. These engines were relatively simple and reliable, but they could be prone to overheating, especially in hot weather or when the vehicle was heavily loaded.

In later years, Volkswagen began using water-cooled engines in the VW Bus. These engines were more powerful and efficient than the earlier air-cooled versions, but they were also more complex and required more maintenance.

EMPI is a company that specializes in aftermarket parts for Volkswagen vehicles. They offer OEM (original equipment manufacturer) certified main bearings and solid lifters for the VW Bus engine. These parts can be used to replace worn or damaged original parts and can help to improve the performance and longevity of the engine.

EMPI main bearings are certified to be manufactured with the same standards and quality as the original parts from Volkswagen. They also offer solid lifters as an option to replace hydraulic ones. Solid lifters are less prone to wear and have no adjustments that need to be made, meaning they’re better suited for high-performance engine builds. They can also help to improve the engine's valve timing and increase its overall power output.

By using EMPI certified main bearings and solid lifters, VW Bus owners can ensure that their engine is running at its best and enjoy the full performance potential of their vehicle.