commandersander

iTrader: (8)

So....

Lots of Internet education has made me dumber....

Mechanically, I am adept and very well worn in. Most important, I diagnose the problem instead of fixing symptoms....

Hopefully you get that I am competent....and I am looking for "real" quantifiable info on this......

Normally, I rebuild a motor with everything at zero...#1@tdc (true, not guessed) cam at 0-0 to crank and dist at about + 10 for first start to keep it fat.....and roll back as needed....

So....and I am assuming here....because I have never put a cam in advance or retard.....as before....0-0

Does advancing the cam diminish or increase the intake cycle (relative to crank rotation).....and obviously.....it would have the same influence on exhaust....right? My thought here is that there is a finite amount of fuel added per power stroke (due to greater vacuum in the chamber) but also a finite amount of heat from delayed dispense of (hot) exhaust....as in more burn, sooner....

What is the real answer? Why do it? And if you change timing, does it not reverse the effort?

To me...as per usual....good here, bad there....

blue thunder

The basic reason one might adv or ret a cam is to move the power band up or down in the rpm range. It is also done to tweek in the dynamic cylinder pressures/compression to right where its desired for the combo. The later the exh valve closes the less dynamic compression that is produced. Distr timing has no effect on cam timing.

rvander68

I ran across this link in another thread somewhere. There is a pretty good explanation in the first few pages or so:

http://www.edelbrock.com/automotive_...ers-manual.pdf

commandersander

iTrader: (8)

Thanks guys.....I wanna do this once!