19221-ZVP-000 Impeller Housing - Overview. The 19221-ZVP-000 Impeller Housing is an essential part of the Honda marine engine cooling system. It surrounds the impeller, directing the flow of cooling water to maintain proper engine temperature and prevent overheating. Engineered to integrate seamlessly with the Honda water pump assembly, it ensures reliable operation and system efficiency by guiding water flow effectively. As a critical element of the water pump system, it supports engine durabil