wachuko wrote:
When it gets to that... where do I remove material from? Since I will not be disassembling the connecting rods from the piston heads I am guessing it will all come from the rods... but where to take any material away from them to do the balance?
Rod / piston assemblies have weight in two categories: Reciprocating = piston and small-end of rod, and rotating = big end of rod.
Both are important in getting the balance correct.
I have never tried (nor heard of anyone else doing so) to balance the small end, complete with the piston. Normal practice is to get the rods as close to each other as they can be, and the pistons as well, and then assembling "matched" pairs.
Having said that, I see no reason you couldn't get reasonable results by balancing them assembled. The issue may be finding a place to remove material to wich access is not blocked by the rod / pin. (Typically, material is removed from the "landing" at the top of the rod, and from the fat bosses on the underside of the pistons.)
The DIY method is to create a freely-rotating fixture with a fixed height between the mounting and a digital scale. I've always tried to get the top of my mounting fixture level with the top of the unweighted scale, but I'm not sure that matters, as long as each rod is measured at the exact same mounting vs height relationship. Allow the free end of the rod to lay on the scale, not the weight. Do the same with ALL of them, and then balace to the lightest one.
then turn it around and weigh the other end of the rod the same way.
theorhetically, you'll come up with assemblies that not only weigh the same (in total) but which carry their weight in the same places.
I'm no Boy-Racer..... but if I can't take every on-ramp at TWICE the posted limit.... I'm a total failure!