Stock 4.0 power

[hillbilly_jeeper]

Forgive me if this has been gone over, im wrong. but why does the HP ratings on all the 4.0's, non HO, and HO, have about the same RPM, but the torque RPM fluxtuates so much? most evey inline 6 engine i've has or seen makes its torque down low, like the renix motors. but according to specks, my 93 HO makes it torque at about 4000 RPM? How does the head redesign and intake account for that much of a change? And im really cuious because my motor loves to pull at about 1800 RPM, right about where i would expect a inline 6 to pull. Can any one help my curiosity??

[theslacker]

the redesigned head has better flow and therefore has less restriction at higher RPM

[hillbilly_jeeper]

I understand that, just not why the dramatic shift in where it makes the torgue. When i put high cmpression pistons, a good intake and better heads and a cam in my 350 in my old chevelle, it make much more power, but the main thing that made a shift in where the power was was the cam. it made power 2000 RPM higher, but lost all the bottom end power. I guess i doubt the number for my 4.0, becasue it still feels like it make so much power down low. what i guess, i want to see, is the torque curve. any dino sheets? is it making good torque at 2000RPM, and pulls pretty flat till it peaks at 4000? im so used to my 350 and seeing a very curved power curve.

[Atl XJ]

It still has a nice flat torque curve, the maximum number is just a little higher.

[hillbilly_jeeper]

It still has a nice flat torque curve, the maximum number is just a little higher.

yeah, it hit me after i was thinkning about it. just because the max torque is at 4000 dosent meen its not making good torque at low RPM. ive just been around so many old chevy and ford inlines, im used to seeing most all the torque below 2000 RPM. But if anyone has any dino sheets, stock or with a few mods, i'd like to see them.

[Dr. Dyno]

yeah, it hit me after i was thinkning about it. just because the max torque is at 4000 dosent meen its not making good torque at low RPM. ive just been around so many old chevy and ford inlines, im used to seeing most all the torque below 2000 RPM. But if anyone has any dino sheets, stock or with a few mods, i'd like to see them.

Here ya go:

http://groups.msn.com/desertxj/dynocharts.msnw?action=ShowPhoto&PhotoID=71