<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by Jettism: as soon as you get the cams change the timing belt if the belt brake you are going to need a new head... like me
Yeh advancing or retarding the timing will move the power band up or down a few hundred RPM to alow you to suit it to your driving.
Low end torque is noticeable, but it isn't night and day. You sacrafice some low end for a much stronger top end.
Advancing the camshaft by 4 degrees will move the power band about 200 RPM lower in the RPM band. Retarding the cam by 4 degrees will likewise move the power band 200 RPM higher in the RPM band.
Short duration with a wide separation angle might be best for towing, producing a strong, smooth low-end torque curve.
Long duration with a short separation angle might be suited for high-rpm drag racing, with a high-end, sharp torque peak. (Crappy idol, the stroke begins moving upward while the valve has yet to close, this alow spend exhaust gasses to be pushed into the intake manifold, that is your reason for shitty idol with long duration cams.
Moderate duration with wide separation angle might be best suited for an all-around street performance engine, producing a longer, smoother torque band that can still breathe well at higher RPM.
I've got another question or two. I've heard that the longer duration you go with the more you will lose when it comes to low end power. This makes sense but to those of you who have these cams in how much do you really lose. Is it noticable or really quite minor? Also is Autotech a good place to go to pick up performance valve springs, retainers, and valves. I know they sell kits with this stuff but is it any good?