The engine was dangerously prone to overheating and suffered from connecting rod or bearing failures. Piston velocity is a test of the strength of the piston and connecting rod subassembly. The piston pins floated in the connecting rod bushings. The movement is derived from a vertical link connected to the connecting rod. However, during the cycle, the angle of the connecting rod changes continuously. The difference in distance travelled is due to the rotation of the connecting rod. Ratio of connecting rod length to stroke, and 3. This inversion is obtained when link 3 (connecting rod) is fixed. Also the crankshaft and connecting rod bearings may seize. The crankpin connects to the larger end of the connecting rod for each cylinder. It also incorporates a crank and connecting rod mechanism. Ralph DePalma's Mercedes again begins to slow with connecting rod problems late in the race. The connecting rod is also called the coupler. The Class J's were rebuilt with a single connecting rod. It is kept together to the connecting rod by removable bolts.