Previous aluminium plates I've made for our old race bike were up to 1.5mm thick. To be affective as a windage plate as well as a baffle you run the oil just below the plate. Because the volume of the crankcase isn't constant as it lessens it will attempt to flex the plate downwards and as it increases the reverse happens so the plate will vibrate like the skin of a drum.   The alloy plates all had a tendency to crack and disintegrate, hence the choice of stainless.   Pete
    • Like