Most oil engines used a separate crank pin box and connecting rod. These were bolted together at the crank end to form the crankpin bearing. Shims could be added or removed to alter the compression ratio, as needed. The Davenport used a simple babbitted connecting rod, precluding any changes, aside from actually repouring the crank end. This design flaw and some others combined with a growing dissatisfaction with small oil engines hastened its demise.