- co ol ing ▁system ▁presented ▁by ▁H onda ▁in ▁ 1 9 6 8 . ▁It ▁had ▁a ▁double ▁wall ▁structure , ▁thus , ▁its ▁name . ▁ ▁In ▁this ▁engine , ▁the ▁cool ing ▁" water ▁jack et " ▁was ▁combined ▁with ▁the ▁concept ▁of ▁air - co o led ▁engine ; ▁the ▁outer ▁wall ▁of ▁the ▁cyl inder ▁block ▁is ▁part ▁of ▁the ▁structure ▁in ▁a ▁two ▁casting ▁m old . ▁It ▁has ▁the ▁cool ing ▁air ▁passage ▁in ▁the ▁space ▁where ▁cool ant ▁would ▁flow ▁in ▁a ▁water - co o led ▁engine . ▁One ▁fan ▁forced ▁cool ing ▁air ▁through ▁the ▁pass ages , ▁while ▁another ▁fan ▁helped ▁remove ▁the ▁he ated ▁air ▁from ▁the ▁engine . ▁Although ▁an ▁all - al umin um ▁engine , ▁this ▁design ▁did ▁increase ▁weight ▁from ▁the ▁usual ▁air - co o led ▁design . ▁ ▁Running ▁g ear ▁The ▁car ▁employed ▁ra ck ▁and ▁pin ion ▁ste ering . ▁At ▁the ▁front ▁it ▁had ▁disc ▁bra kes , ▁with ▁drum ▁bra kes ▁controlled ▁via ▁a ▁dual - line ▁hyd ra ul ic ▁system ▁at ▁the ▁rear . ▁Sus p ension ▁was ▁independent , ▁employ ing ▁Mac Ph erson ▁str uts ▁at ▁the ▁front ▁and ▁an ▁unusual ▁combination ▁of ▁full - width ▁swing ▁ax les ▁and ▁half - elli ptic ▁leaf ▁spr ings ▁at ▁the ▁rear . ▁The ▁front ▁susp ension ▁was ▁substantial ly ▁modified ▁after ▁the ▁car ' s ▁initial ▁presentation : ▁production ▁cars ▁incorpor ated ▁modified ▁front ▁susp ension ▁geometry