rschurr wrote:Hi Allen,
I followed exactly the AOMCC con-rod booklet (by Bruce Longman).
I weighed the con-rods and determined the proportion of the big end.
Then I used strips of lead to simulate the determined weight. I tightened these strips around the crank pins and then turned the crankshaft on the balancing stand. The crankshaft must stop in all positions and no longer turn itself, then it is "static" balanced.
Also with lead strips I determined how much more the bob-weights should be heavier.
Now I brought the bob-weights in each case to the same weight (con-rods and pistons of course as well) and added the tungsten rods using the formula weight of tungsten rod minus weight of the drilled steel, I achieved a net 23 grams per bob-weight.
Thank you Rudolf. I think that I can follow that!
I have an odd pair of crankshafts which I would like to check for balance before use.
Are they the original con rods that you are using? If so, have you carried-out any checks on them (e.g. crack testing?)
Are you going to polish them before re-use?