
1) Beginning half 2) Bi- brother 3) Certain engine 4) Chrysler engine type 5) Chrysler V8 engine 6) Demisemiquaver forerunner 7) Demisemiquaver predecessor 8) Dodge Ram engine 9) Engine option 10) Engine type 11) Fifty percent, up front 12) Fractional prefix 13) Half in front 14) Half of uni- 15) Half up front
Found on
https://www.crosswordclues.com/clue/hemi

A term used to describe any engine that has hemispherical combustion chambers in its cylinder head. Although a four-valve design is more efficient, a hemi head provides room for a pair of large valves and offers good breathing characteristics.
Found on
http://www.caranddriver.com/reviews/glossary-of-terms-info

A Hemi engine has a hemispherical shaped cylinder-head combustion chamber, like a ball cut in half.
Found on
http://www.nhra.net/basics/glossary.html
No exact match found.