Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Help me understand cam timing, advancing or retarding a SOHC for mpg

MetroMPG · 07-03-2015, 10:27 AM

For consideration: 40 teeth on a stock 1998 Metro/Suzukiclone G10 1.0L SOCH cam sprocket = 9 degrees per tooth. Correction: effectively becomes 18 degrees per tooth due to the 2:1 ratio of cam:crank sprockets.

Also: the more efficient XFi cam is reportedly "6 degrees advanced from the stock cam, based on measurements of intake centerline," according to the resident cam guru (superf1y) at teamswift.net.

But the XFi cam lobes also have lower lift & duration.

International heart transplant: the Blackfly gets an XFi cam - MetroMPG.com

07-03-2015, 10:27 AM	#10 (permalink)
MetroMPG Batman Junior Join Date: Nov 2007 Location: 1000 Islands, Ontario, Canada Posts: 22,532 Blackfly - '98 Geo Metro Team Metro Last 3: 70.09 mpg (US) MPGiata - '90 Mazda Miata 90 day: 54.46 mpg (US) Even Fancier Metro - '14 Mitsubishi Mirage top spec 90 day: 70.75 mpg (US) Appliance car Mirage - '14 Mitsubishi Mirage ES (base) 90 day: 62.14 mpg (US) Thanks: 4,082 Thanked 6,978 Times in 3,613 Posts	XFi cam is advanced vs non-XFi For consideration: 40 teeth on a stock 1998 Metro/Suzukiclone G10 1.0L SOCH cam sprocket = 9 degrees per tooth. Correction: effectively becomes 18 degrees per tooth due to the 2:1 ratio of cam:crank sprockets. Also: the more efficient XFi cam is reportedly "6 degrees advanced from the stock cam, based on measurements of intake centerline," according to the resident cam guru (superf1y) at teamswift.net. But the XFi cam lobes also have lower lift & duration. International heart transplant: the Blackfly gets an XFi cam - MetroMPG.com __________________ Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata Honda mods: Ecomodding my $800 Honda Fit 5-speed beater Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage. Ecodriving test: Manual vs. automatic transmission MPG showdown EcoModder has launched a forum for the efficient new Mitsubishi Mirage www.MetroMPG.com - fuel efficiency info for Geo Metro owners www.ForkenSwift.com - electric car conversion on a beer budget