Does Craft have a timeout setting for template requests? I created a RSS feed template and setup a route to it.  If I output more than 40 entries I get a timeout on both FeedBurner and FeedValidator.  Is there a setting in Craft that updates a timeout time or could it be something else going on?
Nothing directly in Craft, but you're probably looking for PHP's max_execution_time, which governs how long a PHP script is allowed to execute.  It defaults to 30 seconds.

You can edit that value from you php.ini file.