Are piston rods supposed to move?
It is going to move sideways some. You need to firmly secure the crank, and see how much is moves up and down on the shaft. Once the piston is on the rod and in the cylinder, lateral movement is not as big a deal as the up and down movement on the rod bearing.
How is rod side clearance used in engines?
This approach minimizes rod side movement with tight clearance between the small end of the connecting rod and the piston pin bosses. This allows the engine builder to use narrower connecting rods and bearings.
What are the limits of connecting rod side clearance?
In regards to connecting rod side clearance, what are the limits beyond the manufacturers specifications that can the be exceeded and if they are, what are the detriments or negatives that can be expected.
What’s the difference between Honda and Honda rod side clearance?
Increasing clearance from 0.0015 to 0.003-inch nearly quadruples the amount of oil flow exiting the bearing. This fits right in with the now-common approach of reducing rod journal size to slow bearing speed. The most popular small rod bearing journal diameter now is 1.850-inch, down from the Honda 1.88-inch bearing.
What happens if the side clearance is out of Spec?
While the side clearance is out of spec, no damage will occur as a result unless this is a high-RPM engine where excessive lateral movement could cause problems. These three books from three very famous and well-respected race engine builders all state that rod side clearance determines oil flow.
This approach minimizes rod side movement with tight clearance between the small end of the connecting rod and the piston pin bosses. This allows the engine builder to use narrower connecting rods and bearings.
Increasing clearance from 0.0015 to 0.003-inch nearly quadruples the amount of oil flow exiting the bearing. This fits right in with the now-common approach of reducing rod journal size to slow bearing speed. The most popular small rod bearing journal diameter now is 1.850-inch, down from the Honda 1.88-inch bearing.
While the side clearance is out of spec, no damage will occur as a result unless this is a high-RPM engine where excessive lateral movement could cause problems. These three books from three very famous and well-respected race engine builders all state that rod side clearance determines oil flow.
Is there a gap between the connecting rods?
For those who demand we cut right to the chase, the gap between a pair of connecting rods does not control the amount of oil leakage past the connecting rods. You would be safe carving that into stone above your work bench.