4.0L HO Jeep Engine Build

ramcharger said

Great info Mopekid! I wanted to use the stock rockers as adjustable roller rockers from MP are almost $900 a set so that dictated cam choices and I'll still have to shim the rockers with the milling that was done. That first Lunati cam is very, very tempting though but I still have to worry about emissions. If I had more money to burn and emissions were not an issue, I'd go with that Lunati and Yella Terra adjustable rockers (about 600 a set). An adustable MAP sensor or possibly a Megasquirt system might be neccesary to take full advantage of that cam though and I haven't researched how that would affect the rest of the computer controlled items like speed sensors, tach, ABS, Speedometer, engine warning lights, etc....

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The first site I linked to has some interesting info on tweaking the timing and A/F ratio. You can add a potentiometer setup to the MAP sensor to tweak the part-throttle A/F, elongate the CPS mounting holes for more timing advance, relocate the MAT sensor to the air cleaner to richen WOT, and add in an adjustable fuel pressure regulator for even more A/F tuning. However this stuff only really works on the '96-down engines, as you said the later OBD-II computers are more sensitive to mods. The auto-trans computers are also a little less tune-able than the manual-trans ones. If you look at that stroker list again you can see the stock PCM is still good up to ~275 HP, even with the "big" Comp 206*/214* @ .050" cam. The trick is properly-sized injectors and playing around with the sensors and fuel pressure. Higher compression would also allow you to run a bigger cam with the stock computer, of course.