Straight cut gears are the preferred racing option. Also, there's that awesome square four whir...
I don't think they should 'mash' though. That sounds a bit harsh. Whir yes, rattle, a little..
They may bed in a bit Malcolm.
'51,'56 Squares, '48 VH, '27 Model C, R67/2, Mk IV Le Mans, '06 Super Duke and Ariel projects.