Balanced bottom end

[Grah]

Guys,

Does anyone know if the machining marks on the underside of the pistons in the pic are balancing marks??
All pistons have different machining marks as do the rods. Each rod, bottom rnd cap and piston weigh exactly the same, 1.412kg. Is this a coincidence?? There are drill holes in the flywheel and the clutch diaphragm?
Any help would be appreciated.

[NO NAME]

I doubt it as the aliminium is pretty light and wouldnt do much but I could be wrong, usually everything is balanced at once (everything that spins of the crank incl the flywheel) and there should be some pretty obvious drill holes in the counterweights on the crank if its balanced

[craiga]

Grah,

If they all weigh the same they are statically balanced, but engine balancing involves dynamic balancing rotating parts such as crankshaft and flywheel/clutch/pressure plate. So the work on the pistons and rods probably does indicate that engine balancing has been carried out at some stage.

Cheers,

Craig.

[Grah]

Thanks guys,

There are drill holes in the crank, grinding marks on the counter balance weights, drill holes in the fly wheel and drill holes in the clutch diaphagm. And the machining marks on the pistons. Reckon it has been dynamically balanced?

Grah.

[HYSTERIA]

I have just had my grey motor fully balanced and the machining marks on the rods are very similar, you'll probably find that one of the rods doesn't have any grinding marks on it, this would be the lightest one, the others will have had material taken off them to match the weights.

jay

[Grah]

Correct, one rod is sans marks. Note that the pic shows a mark on the cap. This was caused by the fuel pump pecker failing at some stage, before my ownership. I found the bits in the sump.