A cloture vote requires 3/5 of the "sworn Senate" or 60 votes to pass. What he can do is force them to talk the entire time by keeping the Senate in session. That is not customary practice anymore. There is a tacit mutual agreement to allow "gentlemens" filibusters where they can threaten fillibuster and that's enough.
http://findarticles.com/p/articles/mi_m1316/is_n11_v28/ai_18855822Also...
"The Senate may end a filibuster by invoking cloture. In most cases, cloture requires the support of three-fifths of the Senate; however, if the matter before the Senate involves changing the rules of the body, a two-thirds majority is required. Cloture is invoked very rarely, particularly because bipartisan support is usually necessary to obtain the required supermajority. If the Senate does invoke cloture, debate does not end immediately; instead, further debate is limited to thirty additional hours unless increased by another three-fifths vote."
http://en.wikipedia.org/wiki/Standing_Rules_of_the_Senate