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Yup, still comes off the base circle at the same point, but from there on, it's 1.6 times lobe lift instead of 1.5, so that gets to .050 lift sooner thus increasing @ .050 duration. As far as advertised duration goes you have to remember that different manufacturers rate adv. dur. at .006, .020 and who knows where else.
it doesn't get to .050 tappet lift any sooner regardless of rocker ratio. the valve will open slightly more at .050 with a 1.6 vs. a 1.5, and likewise on the closing. pretty simple math to find the increase for your camshafts particular lobe. bottom line is you get a little more lift and area under the curve. the actual camshaft duration does not change.
machine shop owner and engine builder
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