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That 3.7L is a V6. The4.0L I6 is what will probably be on it because that is the engine that comes on the other TJ models. At least I hope the V6 is not one of the engine options.

What makes you think that the V6 is inferior to the I6? I have read up on the features of Vs versus Is, and both types seem to have a hard core of fans who insist they are better... but from what I as a layman have read, neither engine style has an absolute edge over the other type.

Approximately 9/30/03 11:57, Joshua Nelson top posted:

All else being equal, it is easier to balance an inline 6 without getting cute with offset cranks, oddball firing delays, etc. None of which particularly matters any more in a modern engine design, which the I-6 ain't, not that that particularly matters either. Engine wars are fought pretty much entirely by the ignorant.

They both have their place. The I-6 has max torque in a lower power band, that's more useful for off-roading. Hence the backlash against putting a V6 in in the TJ.

The V6 will rev high all day and will probably be somwhat more economical.

• * * Matt Macchiarolo
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Not so iron now - it even has alloy pistons [gasp].

Just returned from taking g/f to university - fuel consumption @ constant cruise controlled 75 mph was 20 US mpg / 24 UK mpg over 600 miles ; not too bad really.

Dave Milne, Scotland '99 TJ 4.0 Sahara

"Gerald G. McGeorge" wrote in message news: snipped-for-privacy@corp.supernews.com... : >> Engine wars are fought pretty much entirely by the ignorant.

The rule of thumb is that anything that makes a motor, suspension, anything, better for highway use detracts from the function in an offroad environment, and vice versa. The V6 is a high revving motor that produces its torque and horsepower numbers relatively high in the RPM range, the I6 will produce its torque just above idle speeds.

Let me illustrate the point, would you rather idle over boulders and stumps while gently feathering the gas to keep from stalling, or would you want to be holding the fuel supplier down so that the engine speed was boosted to the point that control was compromised? I want the torque at idle, not half way up the scale.

Highway travel demands the torque to be well up on the RPM scale because that means there is a power reserve that one can tap to climb hills, pass semis, that sort of thing. But, in offhighway travel, one prefers the torque and hp to come in at very low speeds.

If you purpose to buy a Jeep was to drive cross country on the freeway to get to Grandma's house, you want the V6. But, if you are wanting to go trail riding, stump jumping, and rock crawling, then the V6 is the last motor you will want.

That said, I am sure that Bill will tell us about the old 225 ci V6. This is a different beast than today's fuel injected high revving V6's. That old motor was among the most desireable off road motors to ever comme off the line.

Every once in a while I get the chance to drive a Willys era CJ with the

225. It really was a sweet little engine. Not sure what the parts situation is for them these days.

environment,

spam snipped-for-privacy@ev1.net

Very informative. Thank you.

You're welcome. Remember, the question of V6 vs I6 isn't, which is better? The question is, which is better for a particular application?

I have a BMW with an I6 motor, and it revs to 7000 rpm, the I6 in my Jeep is screaming at 3500. The BMW will easily stall from a stop sign on a hill but it will cruise for hours at 100+ mph. The Jeep will pull stop signs out of the ground at idle, even on a hill, but it resists any attempt to go faster than about 70 or 75, and it prefers to cruise at speeds in the 65 range.

So, the I6/V6 question/debate must be refined to the specific V6 and I6 involved. In the case of the Jeep application (particularly the TJ), the I6 is the preferred configuration for the reasons I told you about.

I understand that it is not really the orientation of the cylinders (V-6 vs I-6), but the bore/stroke. Supposedly (given same bore) a longer stroke will produce more torque & a shorter stroke will allow quicker rise in RPM. It is also my understanding that, traditionally, I-6's (in America)have been produced with the longer stroke & V-6's have been short stroke. It would therefore seem that a low RPM, high torque V-6 engine could be produced but, traditionally is not. I would think that the shorter crankshaft of the V-6 would be a plus. I also read that the reason that Chevy built the HiPerf I-6 because it was cheaper (one head, one set of cams, etc)

The short crankshaft of a V6 is more prone to vibration.

Dave Milne, Scotland '99 TJ 4.0 Sahara

: > I have a BMW with an I6 motor, and it revs to 7000 rpm, the I6 in my Jeep : is : > screaming at 3500. The BMW will easily stall from a stop sign on a hill : but : > it will cruise for hours at 100+ mph. The Jeep will pull stop signs out of : > the ground at idle, even on a hill, but it resists any attempt to go : faster : > than about 70 or 75, and it prefers to cruise at speeds in the 65 range. : >

: > So, the I6/V6 question/debate must be refined to the specific V6 and I6 : > involved. In the case of the Jeep application (particularly the TJ), the : I6 : > is the preferred configuration for the reasons I told you about. : >

: >

: >

: >

: > > > >

: > > >

: > > > The rule of thumb is that anything that makes a motor, suspension, : > anything, : > > > better for highway use detracts from the function in an offroad : > environment, : > > > and vice versa. The V6 is a high revving motor that produces its : torque : > and : > > > horsepower numbers relatively high in the RPM range, the I6 will : produce : > its : > > > torque just above idle speeds. : > > >

: > > > Let me illustrate the point, would you rather idle over boulders and : > stumps : > > > while gently feathering the gas to keep from stalling, or would you : want : > to : > > > be holding the fuel supplier down so that the engine speed was boosted : > to : > > > the point that control was compromised? I want the torque at idle, not : > half : > > > way up the scale. : > > >

: > > > Highway travel demands the torque to be well up on the RPM scale : because : > > > that means there is a power reserve that one can tap to climb hills, : > pass : > > > semis, that sort of thing. But, in offhighway travel, one prefers the : > torque : > > > and hp to come in at very low speeds. : > > >

: > > > If you purpose to buy a Jeep was to drive cross country on the freeway : > to : > > > get to Grandma's house, you want the V6. But, if you are wanting to go : > trail : > > > riding, stump jumping, and rock crawling, then the V6 is the last : motor : > you : > > > will want. : > > >

: > > > That said, I am sure that Bill will tell us about the old 225 ci V6. : > This is : > > > a different beast than today's fuel injected high revving V6's. That : old : > > > motor was among the most desireable off road motors to ever comme off : > the : > > > line. : > > >

: > > >

: > > >

: > > >

: > > > > > That 3.7L is a V6. The4.0L I6 is what will probably be on it : because : > > > that is : > > > > > the engine that comes on the other TJ models. At least I hope the : V6 : > is : > > > not : > > > > > one of the engine options. : > > > > >

: > > > > >

: >

: >

: >

: :

I'm not sure I follow. In any given gear, isn't an engine going to give you more power at a higher RPM? Isn't that why the gas pedal is called the "accelerator"? No one ever says "Hey, I need more power, so let me take my foot off the gas pedal!" I don't know about you, but whenever I need more speed or more power, I mash down on the gas pedal to raise the RPMs....

What you are forgetting about is the high torque at low speed is exactly what you want when offroading, high torque at high speed is what you want on the freeway. If the torque comes in at low speeds, then it will be all used up at high speeds, and the ability to accellerate when you are already doing

70 just isn't there.

In an engine that is primarily intended for highway travel, you want the torque and hp to be delivered at high engine speeds. This will allow you to pass other vehicles and climb long hills easily, maybe even speed up while doing it. In an engine that produces its torque at idle, there won't be any more torque available at higher speeds. The result is that climbing long hills may not allow accelleration, and simply maintaining the speed you had at the bottom is all you can hope for when you get to the top. If you come up upon slower moving traffic, and have to slow down because the lane next to you is not empty, you might find that regaining the lost speed is difficult. But, for the trouble at highway speeds, you can pull stumps at idle. If your engine is designed primarily for highway work, then using it in the low speed environment of offroading can be a real chore.

So, I say again, which is better depends upon what you do more. The discussion isn't "any given gear" it is first gear vs 5th gear. The V6 engine in the Liberty is primarily made for flying low to Grandma's house, so it will work much better on the freeway than the I6 in the TJ, but not as good as the I6 when the desire is to go very slow in 1st gear.

The answer is...yes, but a lot depends on where the most useable power is. If you are crawling over rocks, if you mash the gas pedal you will break things and probably people as well. You want an engine that delivers a lot of torque at low speed so you can idle or "blip the throttle" over such obstacles. I've been told that the TJ I-6 developes something like 80% of its peak torque at idle, which is very useful when trail-running. I don't know if that''s a true figure or just marketing, but the TJ I-6 is pretty torquey at low speeds.

Isn't that why the gas pedal is

You are confusing speed with power. If you need more speed, you want hi RPMS and high gearing, if you want power, you want to know where your engine's peak torque is and stay in that RPM range. That's why there's that little lever to the left of your gearshift...pull it to lo range and you can more easily stay in that rpm range while not going so fast you lose control.

• * * Matt Macchiarolo
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Thanks guys, that makes sense. Is there such a thing as an engine that is "torquey" at both low RPMs and higher RPMs, or is that like asking for a perpetual motion machine? (And.... just curious... any idea where the Chevy 350 has peak power, low or high? From the way you've described it, I feel like it's probably low RPM, because I can crawl along at idle and feel like I could rip down a wall but accelerating over 70mph on a hill is tough.. but that could somewhat be a function of the low gears.)

PS - Matt - That little knob is to the RIGHT of the gearshift in a CJ. I'm sure there is a debate thread in the archives about why this is so much better than on the left as in a TJ. :-)