Valve overlap

west coast · 01-24-2017, 12:02 PM

OK going to try and make this simple. I have measured my cam on lift and degrees so i know what the lift is at during every degree of engine rotation. My question is at what lift point do you calculate valve overlap and if it is measured at the lifter lift or multiplied by the rocker ratio for valve lift.So at .050 or something else. i also used Wallace racing calculator but not sure where they measure theirs at and not sure if their calculator is a standard pattern or a roller pattern for the ramps. Not getting into what it should be yet just need to know first then talk about affects and what it should be.

01-24-2017, 12:02 PM	#1
west coast Senior Member Join Date: Dec 2008 Location: Rainy Washington Posts: 609 Likes: 12 Liked 223 Times in 73 Posts	Valve overlap OK going to try and make this simple. I have measured my cam on lift and degrees so i know what the lift is at during every degree of engine rotation. My question is at what lift point do you calculate valve overlap and if it is measured at the lifter lift or multiplied by the rocker ratio for valve lift.So at .050 or something else. i also used Wallace racing calculator but not sure where they measure theirs at and not sure if their calculator is a standard pattern or a roller pattern for the ramps. Not getting into what it should be yet just need to know first then talk about affects and what it should be. __________________ James Boyce 6052 K/SA Stock National record holder 2015,2018,2 times in 2022,2023