Gonna ask a stupid question here, but what metal are you collecting? Don't get me wrong, I understand the idea of collecting ferrous metal shavings as the motor wears, but our motor is almost exclusively aluminium, therefore, non-magnetic, except for the crank, conrods, pistons/rings, cams and valves. Therefore, my thought, and it may be wrong, is that the majority of the metal shavings in the engine would be aluminium shavings and therefore swim by the magnets like sperm on the way to an after-prom party...
