Well, if you really want mechanical engineering texts, here's 11,803 results: https://archive.org/search.php?query=mechanical%20engineering https://archive.org

Well, if you really want mechanical engineering texts, here's 11,803 results: https://archive.org/search.php?query=mechanical%20engineering https://archive.org/search.php?query=mechanical%20engineerin... The Gutenberg collection is quite small.