Model Engine Company of America
Which Way Does the Connecting Rod Go

First determine if your rod is off set or symmetrical. Offset rods are usually made that way to clear a counterweight on the crankshaft. So this is easy to figure out which way it goes.

Symmetrical rods, like this example, must be examined carefully to determine if the lower bushing is countersunk.

On this example you can see a slight countersink on the bronze bushing. This side of the rod will go toward the throw or the cheek of the crankshaft. The countersink is there to clear the small radius left when the crankpin is precision ground.

I have seen some rod that are countersunk on both sides. In this case if the oil holes are symmetrical the rod may be placed either direction.

If the oil holes are not symmetrical I usually suggest that the oil hole should go in the direction to pick up oil on the upward stroke. Although some people argue to the contrary.

The above information is provided as a guide. Since MECOA/K&B has no way of determining the ability of the individual using and understanding this information, we assume absolutely NO RESPONSIBILITY for any damage to person or property from the use of this information.

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