Too Bad they Killed the LL8

[Pittdawg]

The 2014 4.3 liter EcoTec V6 in the new Silvy/Sierra makes 285 hp @ 5300 rpms and 305 lbs torque @ 3900 rpms. While not bad, the eight years older 2006 4.2 liter LL8 I6 makes 291 hp @ 6000 rpms and 277 lbs torque @ 4800 rpms. Just imagine what an updated 2014 4.2 liter LL8 I6 with direct injection and other recent advancements would make? Certainly more than the EcoTec V6. What a bummer. I never understood why the LL8 platform never replaced the 4.3 liter V6 in the full size vehicles.

 

[DocBrown]

Cost. It was expensive to make. And the I6 is noisy as all get out. I loved that engine, but man it was noisy. New diesels are quieter.

The 4.3 on the other hand is esentially just a small block V8 sans 2 cylinders. Its realiable as all get out and very quiet. Even though that version is newer, the 4.3 itself is very old.

When it comes to full size trucks few people get the V6, so why would they put in a more expensive I6? The V8s get just as good of gas mileage and are much more capable.

 

[Sparky]

I don't find the Atlas that loud at all. It is so darn quiet in the cabin sometimes it is surprising. I think part of it was size, it is a massive tall engine, and as long as a V8. It may not fit in vehicles they put the old 4.3 in.

The new gen 4.3 that is based off the new LT1 V8 sounds pretty promising frankly. Smaller package than the LL8 partially because it isn't OHC. Some people seem to believe that OHC is so vastly superior etc but it really isn't depending on the application. DOHC is so stupid huge.

 

[IllogicTC]

The tall deck of the I6 is part of the reason we have that stupid split axle design. And take a look at the torque. It produces a little more, and it produces at a considerably lower range. Low-end is where you want it for hauling applications, the motor doesn't mean squat if it can't get the trailer moving in the first place.

OHC does have its merits. You don't have to worry about lifters if for some reason you're against a technology that's been proven and built upon for decades, and with proper aftermarket support things like hotter cams becomes easier to turn from idea into completed project as they're usually easier to access. But it just isn't for all applications.

As for manufacturing cost, some of that gets shoved onto the end consumer so some portion of it can be subtracted. As far as I know, the other versions of the Atlas are still in production, or at least survived the cut longer than the 6 cylinder. There's more "play" available as the engines are smaller. The I6 weighs over 400 pounds and is fairly long compared to a V6 design (trading length for width, which there is plenty of in a truck).

 

[Pittdawg]

The tall deck of the I6 is part of the reason we have that stupid split axle design. And take a look at the torque. It produces a little more, and it produces at a considerably lower range. Low-end is where you want it for hauling applications, the motor doesn't mean squat if it can't get the trailer moving in the first place.

But you're comparing the 2014 4.3 liter to the 2006 LL8.The 2006 4.3 liter only made 195 hp @ 4600 rpms and 260 lbs torque at 2800 rpms. Apply the same 2014 technology that brought the 4.3 liter's power up 90 hp and 45 lbs torque to the LL8 and were talking upwards of 390 hp and 330 lbs torque, that's my point. That kind of power will move your trailer just fine, trust me

 

[jimmyjam]

But you're comparing the 2014 4.3 liter to the 2006 LL8.The 2006 4.3 liter only made 195 hp @ 4600 rpms and 260 lbs torque at 2800 rpms. Apply the same 2014 technology that brought the 4.3 liter's power up 90 hp and 45 lbs torque to the LL8 and were talking upwards of 390 hp and 330 lbs torque, that's my point. That kind of power will move your trailer just fine, trust me

mmm... 2006 i6 vs v6 is not an apples-to-apples comparison. the atlas engine had every bell and whistle available at the time, electronic ignition, cam phasing, etc. The V6s didn't get overhauled like the V8s did when they released the LS1. the heads had been the same since 1996, although they did add MPFI, but still used a distributor. also the CR is 9.2:1

i like the i6 and all, just too damn tall and long to cram into most cars. and I'm not crazy about working on dohc... aint nobody got time for that!

 

[blazinlow89]

mmm... 2006 i6 vs v6 is not an apples-to-apples comparison. the atlas engine had every bell and whistle available at the time, electronic ignition, cam phasing, etc. The V6s didn't get overhauled like the V8s did when they released the LS1. the heads had been the same since 1996, although they did add MPFI, but still used a distributor. also the CR is 9.2:1

i like the i6 and all, just too damn tall and long to cram into most cars. and I'm not crazy about working on dohc... aint nobody got time for that!

My only issue with DOHC is getting the timing realigned after major work. It really is not that big of a deal, but can be a big PITA if you don't get the cams in the correct sequence with the crank.

 

[Sparky]

But you're comparing the 2014 4.3 liter to the 2006 LL8.The 2006 4.3 liter only made 195 hp @ 4600 rpms and 260 lbs torque at 2800 rpms. Apply the same 2014 technology that brought the 4.3 liter's power up 90 hp and 45 lbs torque to the LL8 and were talking upwards of 390 hp and 330 lbs torque, that's my point. That kind of power will move your trailer just fine, trust me

As jimmy said, it really can't be a direct comparison for the reasons he gave. The old 4.3 hadn't changed much since the 90s and was still old iron SBC-based. The technology advancements from the old to the new 4.3 were huge, enough that I wouldn't even consider them the same engine family aside from happening to have 6 cylinders and same displacement.

The Atlas I6 had many of those advancements over the old 4.3 already. I'm sure they could tweak it now, and maybe do direct injection, but that's about it.

I'm not knocking the engine as I generally really like the Atlas. But I do see why they stopped making it and went back to a V6.

 

[DocBrown]

Actually the production HP/torque figures from the Atlas platform had nothing to do with the technology. In its production form it was tamed from its full potential. The 2002 Chevy Bel Air concept had an I5 Atlas that made 315 horsepower and 315 lb-ft of torque. That tells me that the I6 could have been easily tuned to put out closer 370hp. But then that would have outshined the current 5.3 V8 at the time, and that wouldn't have been good marketing.

 

[IllogicTC]

But you're comparing the 2014 4.3 liter to the 2006 LL8.The 2006 4.3 liter only made 195 hp @ 4600 rpms and 260 lbs torque at 2800 rpms. Apply the same 2014 technology that brought the 4.3 liter's power up 90 hp and 45 lbs torque to the LL8 and were talking upwards of 390 hp and 330 lbs torque, that's my point. That kind of power will move your trailer just fine, trust me

But would it shift the peak torque downward by updating some of the technology? That's the million-dollar question, one the 4.3 already answers and solves. There's a reason they list the RPM the peak was achieved at, some applications require a peak in different areas, and getting a large trailer moving requires it down low.

 

[Pittdawg]

But would it shift the peak torque downward by updating some of the technology? That's the million-dollar question, one the 4.3 already answers and solves. There's a reason they list the RPM the peak was achieved at, some applications require a peak in different areas, and getting a large trailer moving requires it down low.

The LL8 has an amazing torque curve. While "peak" torque is achieved relatively high, 90% of it is available from 1600 rpms. Can't really ask for anything better than that. Is your pcm stock? If so, its the damn pre-programmed "torque management" that neuters the low end of the LL8, not the engine itself. I suggest you have torque management removed asap!

 

[limequat]

The LL8 has an amazing torque curve. While "peak" torque is achieved relatively high, 90% of it is available from 1600 rpms. Can't really ask for anything better than that. Is your pcm stock? If so, its the damn pre-programmed "torque management" that neuters the low end of the LL8, not the engine itself. I suggest you have torque management removed asap!

It always irks me when I hear people complain about the I6 not having "torque down low". My 4200 is stripped of any torque management, drives through a manual trans, and is installed in a 3500 lb vehicle. 1st gear is worthless. By time it hooks, it's time to shift.
There's a video of me on Youtube trying to start in second gear to keep the wheelspin down. Nope, goes sideways immediately.

 

[Ghoster]

There's a video of me on Youtube trying to start in second gear to keep the wheelspin down. Nope, goes sideways immediately.

Come on now..... you can't say something like this without linking to the video!!!

 

[IllogicTC]

If the updated 4.3 has VVT (which is a lot of what allows the LL8 to hold a good torque curve), it's been made obsolete (in the eyes of GM's board, whose sole purpose is to cater not to customers but to stock holders.)

 

[limequat]

Come on now..... you can't say something like this without linking to the video!!!

You're right, how rude of me!

https://www.youtube.com/watch?v=R9Xq_4gc3vQ

about 3:55

 

[IllogicTC]

You're right, how rude of me!

https://www.youtube.com/watch?v=R9Xq_4gc3vQ

about 3:55

*Camera wags back and forth, motioning that the grip isn't exactly gripping
"We're spinning."
Indeed! I like.

And on a side note, I miss some midwest traffic. You're sitting there waiting to turn and all the cars are spaced nice and even and whatnot. Over here everyone behind you will be immediately licking your rear bumper and driving about 20 over. Everyone. No exceptions.