Have added "google site search" back to the site, first with mobile on the bottom of the standard forum search results page, but later on a stand alone page as well (and will add to the desktop version soon).
Search Bar (Bottom of Forum Search Results Page)
Search Results
Will refine this to a stand alone page on mobile and will integrate a similar version into the desktop site soon:
Also there is a stand alone URL link to this Google Site Search as well. Works good, obviously since it's from Google.
UNIX and Linux Forums Google Search Engine