How to Tell If Rods Need to Be Resized

Determining if the connecting rods need to be re-sized is a task that is done when you are rebuilding an engine. During an engine rebuild various parts need to be removed and inspected. When a part is found to be insufficient it will need to be replaced. You can tell if the connecting rods for your engine need to be re-sized by beginning your inspection starting with the engine block.

Instructions

1

Measure the distance from the top of the engine pistons to the top of the block with a ruler. Make a note for each measurement. Different distance measurements will indicate if connecting rods are of different lengths.

2

Examine the wearing of the piston and rod bearing. The wear patterns on both of the thrust surfaces should be uniform. If the wear pattern is not consistent, then a connecting rod may be bent or warped.

3

Locate the rod bearings and examine each one for wear. If a connecting rod is bent or warped it will put an unbalanced load on the bearing. If the bearing shows wear you will see that the top insert is worn on one side and the bottom insert will be worn on the opposite side.

4

Remove the connecting rod and take it to an engine machine shop. The engine machine shop should be able to straighten a bent or warped rod. If the rod is bent more than 15 degrees you will need to re-size a new rod.

5

Examine the rod bolts used to align the cap to the rod. If new bolts will be used or if you have removed the old bolts, the connecting rods will need to be re-sized.