Adjustable cam timing to what degees??

[Anonymous]

I have a 250 2V in a Cortina it has a cam with a duration of 204 at 50 with 110 lobe sep and .420 valve lift. Ive never been real happy with it (less than what I asked for) but apparently Ive been told that because I have an adjustible nine key way timing set I can retard the timing by 4 degree increments which gives about a 200 rpm increase in top end rpm for every increment.
Im not sure but I think the cam at 204 is only good for about 4000 rpm (told a 100 different stories on this) I dont want the power to tapper off until at least 4500.
The car is a manual 4 speed 2.71 diff, elect ingition, 500 holley, exhaust is ported with bigger valves.
Is 212 at 50 too much with this cam will it be ok with the holley (sensitive to duration). Crow rate a cam for this engine with a duration of 214 at 50 and .442 valve lift from 1800-4800 rpm (280 advertised). Any Ideas?

 

[Anonymous]

In general, there are 2 rules for modifying cam timing beyond the "sweet spot" that delivers best overall performance, which I'll call '0 degrees'.

1. Advancing cam timing also advances the point where peak torque and HP appear on the RPM curve, making it happen at lower RPMs.

2. Retarding cam timing delays the point where peak torque and HP appear on the RPM curve, making it happen at higher RPMs.

Both 1 and 2 above make less torque and HP than using the '0 degree' point. They just move the peak around.

Generally, if you advance the cam, advance the static timing and reduce the distributor advance length by an equal amount: vice-versa for retarding so it will still start. You still want about 34-36 degrees overall.