Piston rod caps

[JimH]

A bit confused here. The book says install the piston rod caps with the numbers to the valve side. I have numbers on both sides of the cap. One says 9N and the other side has a number as well. Shouldn't the bearing lock notches line up with each other and should the notches be on the valve side? The book also says the oil hole on the rod itself can face front or back but then this would affect how the bearing notches line up. I'm stuck at this point of the rebuild!

 

[Bob]

IGNORE the (9Nxxx) forging number you have been looking at!

The numbers they are referring to are the match-mark numbers hand-stamped into the rod and it's cap (1 though 4).

Matching these numbers keep each rod and matching cap together AND in the correct orientation to each other.

If in doubt, the rods need to go to an automotive machine shop and have the "big end bore" and the bushing bore checked and sized as needed and the rod checked for straightness.

It is "convention" that the stamped marks be on the valve/camshaft side of the engine, but that is of no actual IMPORTANCE since the rods (as an assembly of cap and rod) can be installed either way with no ill effects.

 

[Bob]

"the rods (as an assembly of cap and rod) can be installed either way with no ill effects."

Let me add that I was referring to the context of this thread... 9n/2N/8N Ford tractor engine connecting rods.

That statement is NOT true for ALL other engines.