'08 Wrangler/Grand Cherokee V6 Owners?

On Sep 9, 4:36*pm, Steve > wrote:
> PhilB wrote:
> >> You're right, the 4.0 wasn't truly underpowered. But the 4.0 was a
> >> torque monster with practical capabilities far beyond what might be
> >> implied by its 190 hp rating. I think just the mere availability of the
>
> > You got it. *I feel like - and I mean this in a good way - like I'm
> > driving a tractor with my 98 Jeep. *It sounds different also.
>
> Reading Bill Weertman's book on Chrysler engines was enlightening.
> Weertman is a retired Chrysler engine designer, 1949-circa 1990,
> part-time after 1990, worked on the 50s Hemis, the original B/RB
> big-block v8 engines, the A and LA small block v8s, the slant-6- pretty
> much every engine from the first V8s through the 3.3 v6, and then
> consulted on the Viper v10. When he retired he was, IIRC, the head of
> the engine department.
>
> His book also had chapters on the non-Chrysler engines that Chrysler
> inherited or used, including all the AMCs (the 360 v8, the 258 six, and
> the 2.5/4.0 family). The really interesting thing is how impressed he
> seemed to be with the 2.5/4.0 in particular. He never outright says,
> "this engine was a complete POS and Chrysler *should have kicked it in
> the weeds" about any engine although he comes really close to saying
> that about the PRV v6 from the Eagle Premier. But its more an absence of
> any praise at all, rather than criticism. The really telling fact was
> how much positive stuff he included about the the AMC/Jeep 2.5L, and
> noted that it had much higher output than any normally aspirated form of
> his own 2.5L SOHC engine. Chrysler ultimately switched the rear-drive
> application of the Chrysler 2.5 (the Dakota) over to the Jeep engine
> when there was no longer a need for the FWD version of the Chrysler 2.5.
> He also gave the 4.0 high marks (the 4.0 is the same basic block as the
> 2.5 with a longer stroke and 2 more cylinders- the blocks were even
> finished on the same assembly line.) If anyone had a right to be
> institutionally biased against the 2.5 and 4.0, it might have been
> Weertman. But he loved 'em, and that's a pretty strong testimonial.

They were stout, I guess. But 190 hp in the so-called "high output"
version? Honda gets more than that out of a 2.4 L IL-4 in the Accord.

Lloyd wrote:

>
> They were stout, I guess. But 190 hp in the so-called "high output"
> version? Honda gets more than that out of a 2.4 L IL-4 in the Accord.

Unless you've ever actually used one offroad, you just won't get it.
Even onroad, its a lot of fun in city driving. The horsepower rating
really means nothing- its the torque delivery of the 4.0 that makes it
so superb. The torque peak is at 3000 RPM (1996 and up engines, it
peaked at 4000 for the earlier engines), but its really basically just a
flat line from 1500 to around 4400, and there's plenty at *idle* to
crawl over huge rocks in 4-low. 190 HP *is* impressive for a gasoline
engine that delivers torque that way and is only a 4L. Most comparable
torque engines up to that time had barely over 100 horses and many
displaced a lot more than 4 liters. Today, that whole segment has been
pretty much taken over by diesels. Its *not* the engine you want in a
sports sedan, luxury car, or 3/4 ton pickup. Its *exactly* the engine
you want in a Jeep. By contrast, you wouldn't get 50 feet offroading
with a Honda engine under the hood, even if it had 250 hp at 7500 RPM.
There'll never be a replacement to match the 4.0, although the 3.8 comes
about as close as anything I can think of as I already said.

On Sep 13, 1:19*pm, Steve > wrote:
> Lloyd wrote:
>
> > They were stout, I guess. *But 190 hp in the so-called "high output"
> > version? *Honda gets more than that out of a 2.4 L IL-4 in the Accord..
>
> Unless you've ever actually used one offroad, you just won't get it.
> Even onroad, its a lot of fun in city driving. The horsepower rating
> really means nothing- its the torque delivery of the 4.0 that makes it
> so superb. The torque peak is at 3000 RPM (1996 and up engines, it
> peaked at 4000 for the earlier engines), but its really basically just a
> flat line from 1500 to around 4400, and there's plenty at *idle* to
> crawl over huge rocks in 4-low. 190 HP *is* impressive for a gasoline
> engine that delivers torque that way and is only a 4L.


Not really. 225 lb-ft is not impressive for a 4 L. You might take a
look at the torque curve of the Toyota 4.0 L

http://brockandbecca.com/files/fj/FJ_NewCarFeatures.pdf

Looks like 230 lb-ft at 1500 rpm, more than the Cherokee's peak
torque.

>Most comparable
> torque engines up to that time had barely over 100 horses and many
> displaced a lot more than 4 liters. Today, that whole segment has been
> pretty much taken over by diesels. Its *not* the engine you want in a
> sports sedan, luxury car, or 3/4 ton pickup. Its *exactly* the engine
> you want in a Jeep. By contrast, you wouldn't get 50 feet offroading
> with a Honda engine under the hood, even if it had 250 hp at 7500 RPM.
> There'll never be a replacement to match the 4.0, although the 3.8 comes
> about as close as anything I can think of as I already said.

Lloyd wrote:

> Not really. 225 lb-ft is not impressive for a 4 L.

One number again. Means nothing, unless it maintains that number from
idle to 4000 RPM.

>You might take a
> look at the torque curve of the Toyota 4.0 L

You can be impressed by whatever you want, but the FJ Poseur's engine
has a peaky torque curve compared to the Jeep, despite the fact that it
*should* reflect 25 years of technology improvement.

On Sep 13, 5:29*pm, Steve > wrote:
> Lloyd wrote:
> > Not really. *225 lb-ft is not impressive for a 4 L. *
>
> One number again. Means nothing, unless it maintains that number from
> idle to 4000 RPM.
>
> >You might take a
> > look at the torque curve of the Toyota 4.0 L
>
> You can be impressed by whatever you want, but the FJ Poseur's engine
> has a peaky torque curve compared to the Jeep, despite the fact that it
> *should* reflect 25 years of technology improvement.

If it starts out higher then the old 4.0 L and then gets higher still,
that's better than flat. Heck, a 1908 engine has a very flat torque
curve, but it's also very low.

Lloyd wrote:

> If it starts out higher then the old 4.0 L and then gets higher still,
> that's better than flat.

Depends on how much weight it has to haul, and whether or not it really
does start out higher and get higher. A Cummins N-14 starts out higher
and gets higher too, but since it weighs more than a Wrangler all by
itself..... :-p


But that's not the point. The Jeep engine did its thing in 1988- that's
20 years ago, and if anyone has actually made a better offroad engine
for light vehicles, its only better by a tiny fraction. Certainly no one
makes one that really represents 20 years worth of progress the way
comparing, say, a 5.7 Hemi to a 1988 360 shows progress.