27-11-2020, 11:08 AM
As a guide, the density of rod metal is about 7, so 21 grams will have a volume of 3 cc or 3000 cubic millimetres.
That's about the size of a big lump of sugar and sounds like rather a lot of metal to be removing.
When I rebuilt my 2 bearing engine, I didn't know that there were early and late pattern 2 bearing rods with different weights, about 320 and 370 grams respectively but with some variation. I only discovered this after weighing my newly re-metalled rods and finding one light one
. After contemplating filing off metal or attaching lead weights, the solution I went for was to buy another late rod.
I then ended up with rods of 361, 363, 370 and 372 grams, so I placed the 370 and 372 at cylinders #1 and #2, and the 361 and 363 at cylinders #3 and #4. This has been successful.
My notes from the time tell me that a big end bolt washer weights 0.25 grams, a gudgeon pin weighs 37 grams and a piston weighs 135 grams.
That's about the size of a big lump of sugar and sounds like rather a lot of metal to be removing.
When I rebuilt my 2 bearing engine, I didn't know that there were early and late pattern 2 bearing rods with different weights, about 320 and 370 grams respectively but with some variation. I only discovered this after weighing my newly re-metalled rods and finding one light one
. After contemplating filing off metal or attaching lead weights, the solution I went for was to buy another late rod.I then ended up with rods of 361, 363, 370 and 372 grams, so I placed the 370 and 372 at cylinders #1 and #2, and the 361 and 363 at cylinders #3 and #4. This has been successful.
My notes from the time tell me that a big end bolt washer weights 0.25 grams, a gudgeon pin weighs 37 grams and a piston weighs 135 grams.