Weight variation on M30 connecting rods

[kkro]

Hi guys

I am currently assembling a M30B32 engine for my E3 3.3Li. I do have a tread in the E3 forum, but I just wanted to make all of you aware of my observations.

As a part of my assembly procedure, I weighed all the pistons and rods. I also weighed pistons and rods from two other M30 engines just for reference. What I found about rod weights surprised.

I weighed rods from 3 different engines. The rods looks the same, so I would not guess them to vary a lot. I was very wrong!

The weight variations within each set of 6 rods were very small (+/- 1g), but the variation between different sets were surprisingly big. The lightest rod was 699g and the heaviest was 749g, so there was a variation of 50g or 7,2%.

So my take from this is that M30 rods should be weighed to confirm they come from a weight-matched set of 6 rods.

 

[Honolulu]

Actually I think your observation that the rods in each set were within 1 gram of each other is all one needs to know. They are weight matched, as long as one doesn't mix a rod from another engine. But checking is a good idea, who knows what may have happened in the past,