Hello From Kansas!

[bmorgil]

The offset is different on the rods. The offsets position the rod in the middle of the piston. The engine will go together just fine with the rods in the wrong place. The small end of the rod will be positioned off to one side of the piston instead of the middle. This will increase the side load on the piston and heavily tax the rings. It usually will scuff the cylinder wall and/or break a ring after it runs for a while that way. I have taken one apart that ran with an even rod in number one cylinder. Eventually it broke the piston lands, the rings and grooved the bore.

[Mike P]

The offset is different on the rods. The offsets position the rod in the middle of the piston. The engine will go together just fine with the rods in the wrong place. The small end of the rod will be positioned off to one side of the piston instead of the middle. This will increase the side load on the piston and heavily tax the rings. It usually will scuff the cylinder wall and/or break a ring after it runs for a while that way. I have taken one apart that ran with an even rod in number one cylinder. Eventually it broke the piston lands, the rings and grooved the bore.

So I’m assuming then that there are different part numbers? Is there a way to tell which one is for which position without part numbers?

[bmorgil]

The part numbers are different. 641774 for the odd rods and 641775 for the even. You usually buy them by the position however. A lot of people sell the used rods as a "number one" or a number two" rod etc. The rods are stamped 1, 2, 3, and 4. The sellers usually just note the rod number.

[Mike P]

The part numbers are different. 641774 for the odd rods and 641775 for the even. You usually buy them by the position however. A lot of people sell the used rods as a "number one" or a number two" rod etc. The rods are stamped 1, 2, 3, and 4. The sellers usually just note the rod number.

Oh gotcha. My MB engine was apart (well the pistons/rods were out) when I got it. I did notice the rods were stamped but I just assumed whoever took it apart did that. Thanks again! Let me know when you get tired of my questions, ha!