> My brother is installing the two new carbon blocks (as sold by Moss) in
> 1-speed TR4 wiper motor and wondering which way the grooves in the carbon
> blocks go. Do the carbon block's grooves go parallel with the shaft and
> commutator or should they run perpendicular?
> '63 TR4 since '74
Contours on your brushes should match the contour of your commutator. The
idea is to have as much electrical surface working as possible. But don't
worry overly much, and have a beverage of some sort. If you get it wrong
and it actually fits, it'll wear into the right shape soon enough.