Shiv, just exactly what effect on the whole combustion process do the cam gears have? In relation to the ignition timing, etc. I know that they are recommended because their end affect is reduced knock up top, but how is that accomplished? What does retarding the vavle timing do?

 

i'm not shiv but this was kind of helpful:

http://www.prostreetonline.com/pso/p...sp?articleid=7

 

very informative.

 

Yeah, those parts I understand. I just wanted to know more of the, "it causes this and this is the results because". And also wanted to know how he uses that with ignition timing, etc. I guess a little more in depth. Also, I know how overlap affects NA motors, just not sure what is going on with a FI motor.

A very good link though, thank you much.

 

ok here is an uncompressed version :-D

http://www.realoldspower.com/tech/valve_timing.htm

You may want to skip ahead to the last paragraph that begins "All of the above statements deal directly with typical naturally aspirated combinations."

This still does not deal with spark timing but it is a pretty good explanation of the different factors that go into optimizing cylinder filling.