Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Reed valve in intake = 'infinitely variable' cam timing

serialk11r · 10-06-2022, 07:40 PM

I imagine there would be a clacking sound at idle which would be really annoying? Don't see why the concept wouldn't work though, it's basically crude VVT. That said I am not sure this is worth the effort, since it mostly improves idle.

My V8 engine has very hot cams (peak power at 7600rpm) and IIRC it'll idle as low as 620rpm (I have it set to 675, that's about where the fuel consumption stops improving from dropping the speed). That said, if the coolant temp is at say 85C instead of 100C the fuel burn is WAY higher (like 25%), so it's clearly sensitive to that exhaust reversion.

10-06-2022, 07:40 PM	#8 (permalink)
serialk11r Master EcoModder Join Date: Jan 2012 Location: United States Posts: 1,756 spyder2 - '00 Toyota MR2 Spyder Thanks: 104 Thanked 407 Times in 312 Posts	I imagine there would be a clacking sound at idle which would be really annoying? Don't see why the concept wouldn't work though, it's basically crude VVT. That said I am not sure this is worth the effort, since it mostly improves idle. My V8 engine has very hot cams (peak power at 7600rpm) and IIRC it'll idle as low as 620rpm (I have it set to 675, that's about where the fuel consumption stops improving from dropping the speed). That said, if the coolant temp is at say 85C instead of 100C the fuel burn is WAY higher (like 25%), so it's clearly sensitive to that exhaust reversion. Last edited by serialk11r; 10-06-2022 at 07:48 PM..