L51511 Deactivating Power Cylinders under Reduced Load on Two-Cycle Engines

Investigates potential and procedures for selective deactivation of one or more power cylinders in two-cycle engines under reduced load to effect fuel savings while avoiding possible engine derangement. The objectives were to identify any major problems with cylinder deactivation, to quantify likely benefits, to determine potential increases in load or stress, and to generate guidelines from the project results. This study showed that economic benefits are possible with the careful use of cylinder deactivation; however, several operational problems were encountered, such as spark plug fouling, oil pumping, increased noise due to a mismatched muffler cutoff frequency, and increased wear in the deactivated cylinders.