its ▁starting ▁in ▁ 1 9 9 5 . ▁ ▁Vari ants ▁ ▁O - 3 2 0 ▁series ▁EC i ▁O - 3 2 0 ▁▁ ▁at ▁ 2 7 0 0   r pm , ▁Min imum ▁fuel ▁grade ▁ 1 0 0 / 1 0 0 LL ▁av gas , ▁compression ▁ratio ▁ 7 . 0 : 1 . ▁Cert ified ▁App lications ▁EC i ▁O X - 3 2 0 ▁▁ ▁at ▁ 2 7 0 0   r pm , ▁Min imum ▁fuel ▁grade ▁ 1 0 0 / 1 0 0 LL ▁av gas , ▁compression ▁ratio ▁ 7 . 0 : 1 . ▁Ex perimental ▁Vari ant ▁EC i ▁IO X - 3 2 0 ▁▁ ▁at ▁ 2 7 0 0   r pm , ▁Min imum ▁fuel ▁grade ▁ 1 0 0 / 1 0 0 LL ▁av gas , ▁compression ▁ratio ▁ 7 . 0 : 1 . ▁Fe ul ▁In ject ed ▁Ex perimental ▁ ▁App lications ▁ ▁Spec ifications ▁( EC i ▁O - 3 2 0 ) ▁ ▁See ▁also ▁List ▁of ▁aircraft ▁engines ▁ ▁References ▁ ▁External ▁links ▁ ▁Category : Box er ▁engines <0x0A> </s> ▁Robert ▁Living ston ▁Den ig ▁Sr . ▁( Se ptember ▁ 2 9 , ▁ 1 8 8 4 ▁– ▁July ▁ 2 5 , ▁ 1 9 7 9 ) ▁was ▁a ▁decor ated ▁United ▁States ▁Marine ▁Corps ▁brig ad ier ▁general ▁who ▁served ▁in ▁World ▁War ▁I , ▁and ▁served ▁as