I've been reading up a little on cam timing. I know that advancing the cam timing pushes the powerband to a lower rpm, and retarding it pushes it to a higher rpm. However, I'm not really interested in my powerband as much. I'm interested in getting good fuel economy. Most of the info out there is mostly on how to make more power... bleh.
The wikipedia on
variable cam timing says that advancing AND retarding intake cam timing can be good for fuel efficiency. Thats not super helpful.
It seems to indicate that advancing the exhaust cam is good for fuel economy, and retarding it is good for power.
I'm also mainly thinking about the Metro which is a SOHC. I don't have the ability to advance just the intake cam because there is only one cam.
So, I'm thinking I want to advance the cam timing, but not 100% sure why, and I'd really love to fully understand it. I know the atkinson cycle engines retard it so it pushes some of the intake charge out the valves, but thats retarding the cam, not advancing.
Does anyone have some good resources, or a great explanation as to why advancing or retarding is good for fuel efficiency.