Is "logicalising" a valid word? [closed]

"Logicalise" already exist as a word, and it already means something other than the definition you listed. It means "to reason, to think, to use or apply logic", without the connotation of trying to make something illogical into something logical. For example, see here:

https://www.merriam-webster.com/dictionary/logicalizing

https://en.wiktionary.org/wiki/logicalize

http://www.thesaurus.com/browse/logicalize

The word you might be looking for is "rationalise" or its various synonyms.

rationalise: attempt to explain or justify [something] with logical, plausible reasons, even if these are not true or appropriate. (from ODO)