Development Of The Next Generation Medium-duty Natural Gas Engine: Final Report

This report summarizes the work done under this subcontract in the areas of System Design, System Fabrication, and Experimental Program. The report contains the details of the engine development process for achieving throttleless stratified charge sp... Read more

This report summarizes the work done under this subcontract in the areas of System Design, System Fabrication, and Experimental Program. The report contains the details of the engine development process for achieving throttleless stratified charge spark ignition (SI) engine operation as well as advanced turbocharging strategies. Engine test results showing the potential of the direct-injection stratified charge combustion strategy for increasing part-load engine efficiency on a John Deere 8.1-liter natural gas engine are also included in this report. In addition, steady state and step transient engine data are presented that quantify the performance of a variable geometry turbocharger (VGT) as well as a modified waste-gated turbocharger on the engine. The benefits of the technologies investigated during this project will be realized in the form of increased drive-cycle efficiency to diesel-like levels, while retaining the low emissions characteristics of a lean-burn natural gas engine. Less