Connecting Rod Retainers

[Rick Allen]

Assembling my R2 engine, these retainers or locks came with some small parts along with the complete engine kit, some people say to use them on the nuts on the connecting rods other people say not to, as they may come loose and fall off in the engine.

Wondering what the consensus is, to use them or not to use them, and if so, should they go on with the top facing up or opposite? Also just how tight to put them on, don't know if there's a torque rating for something this light duty or not, I have provided pictures of them going on either way as an example,,,