Characteristics of a Four Cylinder Hydrogen-Fueled Internal Combustion Engine

The purpose of this paper is to review the results of an experimental test program conducted on a commercial four cylinder spark ignition internal combustion engine. Corrected brake horsepower, corrected brake mean effective pressure and enthalpy efficiency are presented covering equivalence ratios from .42 through .63 at MBT timing under full load (or equivalently, wide open throttle) conditions. In addition, advanced cam timing was studied as a means of improving control of the hydrogen combustion rate and found to be ineffective. MBT timing characteristics suggest a marked increase in flame speed at full load operation for engine speeds above 1500 rpm, which is independent of equivalence ratio and cam timing.