Many palindromes found on websites etc are merely collections of words that make little, if any, real sense or are not in ‘normal' English and without sense and normality there is little point in creating palindromes.
Click
http://complex.gmu.ed.../personnel/ernie/witt
y/palindromes.html for a site with loads...some sensible and others not.
I like "Norma is as selfless as I am, Ron." (25 letters) That one has the inestimable advantage of being in standard English and it makes perfect sense. (As a matter of interest, it came from a brief trawl through those on the website-link provided above.)