I found the solution here
http://wordpress.org/support/topic/wp_query-filters-1?replies=3
using the query filter posts_where
Strangely when I apply a filter it will display all the post types/ ie pages/revisons and posts in the results, whereas before it just displayed the posts.
It's easy to set the filter to pagetype=whatever but something to look out for, I'm not sure I assume it does this as the posts_where writes over a certain part of the query