SE spring failure28 Jan, 2017 in Head Hoggers tagged harley engine kits / harley engine machining / harley head porting / harley serivce / Head Hoggers by headhoggers (updated 2806 days ago) This is a common failure we see with SE valve springs with good size cam lift. DO NOT just put bigger lift cams in your bike! Please ask a professional for advice if you do not know yourself.