stroke , ▁ 9 0 ° ▁V - t win ▁engines , ▁with ▁a ▁des mod rom ic ▁val ve ▁design . ▁Duc ati ▁refers ▁to ▁this ▁configuration ▁as ▁L - t win ▁because ▁one ▁cyl inder ▁is ▁vertical ▁while ▁the ▁other ▁is ▁horizontal , ▁making ▁it ▁look ▁like ▁a ▁letter ▁" L ". ▁Modern ▁Duc atis ▁remain ▁among ▁the ▁dominant ▁performance ▁motor cy cles ▁available ▁today ▁partly ▁because ▁of ▁the ▁des mod rom ic ▁val ve ▁design , ▁which ▁is ▁near ing ▁its ▁ 5 0 th ▁year ▁of ▁use . ▁Des mod rom ic ▁val ves ▁are ▁closed ▁with ▁a ▁separate , ▁dedicated ▁cam ▁lo be ▁and ▁lif ter ▁instead ▁of ▁the ▁conventional ▁val ve ▁spr ings ▁used ▁in ▁most ▁internal ▁comb ust ion ▁engines ▁in ▁consumer ▁vehicles . ▁This ▁allows ▁the ▁c ams ▁to ▁have ▁a ▁more ▁radical ▁profile , ▁thus ▁opening ▁and ▁closing ▁the ▁val ves ▁more ▁quickly ▁without ▁the ▁risk ▁of ▁val ve - float , ▁which ▁causes ▁a ▁loss ▁of ▁power ▁that ▁is ▁likely ▁when ▁using ▁a ▁" pass ive " ▁closing ▁mechanism ▁under ▁the ▁same ▁conditions . ▁ ▁While ▁most ▁other ▁manufact ur ers ▁use ▁wet ▁cl ut ches ▁( with ▁the ▁spin ning ▁parts ▁b athed ▁in ▁oil ) ▁Duc ati ▁previously ▁used ▁multi plate ▁dry ▁cl ut ches ▁in ▁many ▁of ▁their ▁motor cy cles . ▁The ▁dry ▁cl utch ▁elimin ates ▁the ▁power ▁loss ▁from ▁oil ▁vis cos ity ▁drag ▁on ▁the ▁engine , ▁even ▁though ▁the ▁eng agement ▁may ▁not ▁be ▁as