Walker Engineering - Home Welcome to Walker Engineering - home of the Walker AIRSEP closed crankcase system for diesel engines. Originally configured for marine applications, the AIRSEP is now available for all applications that use diesel engines, such as trucks, buses, RVs, Industrial engines, and even power generation. New AIRSEPS have been designed to meet the increasing popularity of natural gas-fueled engines, as well. For heavy-duty applications, our high-efficiency CCE series AIRSEP is the product of choice. A private company, Walker Engineering offers innovative products that apply cu