Help needet, I have these silly engine conversion projects coin on. I ´m planning to use different motor crankshaft to get longer stroke. Case space is a problem exspecialy room for counterweights. I have studiet crankshaft vibration theories BUT they are all from racing enviroment talk. Nothing to us under 3000 rpm. direct driwe guyis. My Vauxhall from seventies doesend have counterweights, only heavy flywheel. I´m talkin straight four now. Do I need cw.s to crank that spins under 3000. Those old sidevalve Fords and Aircraft inlines have no cw.s. What if I cut them away.