This is not as common as the other form of Gordonia, the variety usually seen in folk's gardens, G. axillaris.
G. axillaris has a more attractive shape and smaller, single flowers, and the bark of the tree has an attractive reddish tinge to it. Nevertheless, this one is flowering nicely this year. I bought it back in 2002 as a present for my wife, she saw it in a nursery and quite 'took' to it. Sorry Chas, to the best of my knowledge, I don't think it has a 'common' name
B.