How do I find abbreviation of the journal name Engineering?
How to find journal title abbreviations? (in general)
There are various sources of abbreviated journal titles, and though most of the time they agree, there are definitely cases where they do not. So:
Check the citation style of the journal you're writing for (if any). They may specify an authority on abbreviations, or specify that journal names are not to be abbreviated.
Then, see if the journal you're looking for is included in the authoritative list.
If it's not covered, then then the best source for information is the cited journal itself! How do they abbreviate their own name, e.g. on article page headers/footers, or in citation to articles from their own journal?
An alternative is to look into one of the very large citation indexes, such as Web of Science; they maintain a list of journal abbreviations for the journals they index.
What about Engineering?
Well, that's not an easy case. First, it's a very low-profile journal: despite its claims that it is “indexed by several world class databases”, I don't think it is. Let's take ISI Web of Knowledge, which they cite as their first example. It indeed has a journal named Engineering – London in its index, but a quick search reveals it is another journal entirely, published between 1969 and 1994. Moreover, the citations given as justification in a screenshot by the publisher of the modern-time Engineering cannot be found on the journal.
So, the journal is not present in the ISI index, and does not given information about how to abbreviate its name (it does not use journal abbreviations in its succinct style guide). In other engineering journals, the word Engineering is usually abbreviated as Eng. So, either go with that, or use the full name and let the copyeditor worry about it.
In addition to the answer by @F'x, there is one more resource: the List of Title Word Abbreviations (LTWA), which, according to Wikipedia, is "the complete list of ISO 4 standard abbreviations"; ISO 4, in turn, "is an international standard which defines a uniform system for the abbreviation of serial titles" (Wikipedia again).
The LTWA (not to be confounded with the Library of Tibetan Works and Archives, by the way) is accessible here. It's a little tricky to use since entering "Engineering" in the search box only yields a match for "neuroEngineering": LTWA stores entries in their most general form. (You'll see what that means.)
Successively remove letters from the end of the search word to find what you are looking for:
How to read this? Any English word beginning with "Engineer" (including Engineering) is abbreviated as "Eng." So, the "Journal of Engineering" becomes "J Eng" or "J. Eng." (because "Articles, conjunctions and prepositions shall be omitted from title abbreviations" [with some exceptions]; ISO-4, section 4.3).
There is one more caveat, however: "Titles consisting of a single word, exclusive of an article or preposition, shall not be abbreviated." (ISO-4, section 4.2). So, "Engineering" remains "Engineering" - there is no abbreviation.
The third edition of ISO-4 is currently available here, but I doubt it will stay there forever.