I was trying to do a little math and seem to be missing something, I'm trying to calculate the bob weight of my steel rod combo. Here's the numbers: piston 647 pin 156 rings 55 locks 5 rod 797 brg 41 sm rod 237 (small end of the rod) lg rod 560 ( large end of the rod) Ok the formula I have is 50% of the reciprocating and 100% of rotating weight. By my calculations that comes to 1155 bob weight. What am I missing? Do you somehow also include the crank in some way?
As far as I know, Reciprocating weight = Piston + Pin + Locks + Rings + Rod Small End. Rotating Weight = (Bearing + Rod Big End) x 2 because of two rods per journal Bob Weight = Reciprocating + Rotating + a few grams for oil Devon
