cam timing

[pud]

anyone ever play with their cam timing? Ive heard from a few 5.0L truck guys that advancing 4 degrees gave them some more grunt.

[SpartanDieselTech]

Originally Posted by pud

anyone ever play with their cam timing? Ive heard from a few 5.0L truck guys that advancing 4 degrees gave them some more grunt.

Currently, all the Powerstrokes have pressed-on and key-fitted gear drives, so none of it is adjustable.

Retrofitting an adjustable unit has been on my to-do list for a period of time, but the opportunity and money to pursue the issue hasn't been around lately.

It will likely involve removing the gear, machining it to fit the adjustable unit, then remaching the rear of the cam to fit.

[pud]

what about the CPS...would adjusting the cam throw it out however many degrees you advance/retard?

[BowTieHatr]

you would definitely have to adjust the computer because you will throw sync off if you just advance the cam.

[SpartanDieselTech]

Originally Posted by BowTieHatr

you would definitely have to adjust the computer because you will throw sync off if you just advance the cam.

There are function tables in the PCM; functions of rotational speed of the cam sensor peg and milliseconds of peg duration, on and off. These aren't accessible with our SCT software, but I marked them while digging for some other parameters with a CarDAQ unit a while back. If I went back into it, I could write a set of values for each half degree of advance or retard that was desired, and make the values from +10 to -10 degrees available as hex values files insertable into an Xcal2 .mtf file for anyone using custom tuning.

These tables would need to be changed dynamically depending upon engine speed by adding or subtracting milliseconds of inferred duration of the peg both on and off, but I don't think it would be all that hard to do.

[BowTieHatr]

well it probably would not be hard, but you would have your hands full.