AL M Posted February 12, 2007 Share Posted February 12, 2007 My cam specs are 230/236 duration and 490 lift.. I'm running 1.6 rr and I've read somewhere that the lift will increase to 523 w/the 1.6's. My question is does the duration increase as well?...just curious...Al Link to comment Share on other sites More sharing options...
Sam (Bones) Posted February 12, 2007 Share Posted February 12, 2007 nope, the opening point and closing point will stay the same, if you take the lift of the cam (lobe lift not valve lift)and multiply it by 1.6, you will have the valve lift Link to comment Share on other sites More sharing options...
AL M Posted February 13, 2007 Author Share Posted February 13, 2007 Thanx a bunch! Link to comment Share on other sites More sharing options...
72 LS5 Posted February 13, 2007 Share Posted February 13, 2007 I would think the duration at .050" would be affected, but very slightly. With the 1.6 rockers, the valve would be reaching that .050" earlier than with 1.5s and shutting later (slightly). But total duration would not be affected. No matter what the rocker, the valve is shut when on the base circle of the cam. Link to comment Share on other sites More sharing options...
kc8oye Posted February 25, 2007 Share Posted February 25, 2007 according to my rebuilding SBC's book, yes, the increase in rocker arm ratio effectively increases duration by a small ammount.. can't remember what off hand. Link to comment Share on other sites More sharing options...
AL M Posted February 25, 2007 Author Share Posted February 25, 2007 Thanx for the 411 guys. Anyone know how to figure this one out? Link to comment Share on other sites More sharing options...
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