glass slipper

Cadillac was going to use the LT1 in their new 2014 ATS-V with VVT and cylinder deactivation...the following link approximate specifications reveals 470 HP@6200 RPM. I'm guessing at least another 5-10 HP in C7 trim.

http://www.autohotest.com/2165/2014-...atsv-470hp-v8/

Will this make all of the people "disappointed" with 450 HP happy?

Jinx

First clue -- date of article: February 7, 2011
Second clue -- there will be no 2014 ATS-V; 2015 at earliest
FWIW, the rumor mill on the ATS-V says it's more likely to get a turbo V6.

Jp23rockstar

but I hope the ats v gets the lt1 instead though. The v series should be exclusively v8. Let cadillac use the turbo 6 for the regular ats to compete with BMW 335i.

235265283...

Two interesting (or confusing) things in the ATS-V specifications part of your linked article:

"...w/ independent intake & exhaust VVT"

"Compression Ratio: 12.3:1"

Something fishey here.

235265283...

OK, I see from the two contemporaneous posts that I mistook this article as recent GM-released information (i.e., factual). My bad.

glass slipper

Yes, I edited my post to reflect no 2014 ATS-V. However, the date of the article does not mean the info isn't relative. The HP of the 1990 ZR-1 was known in 1987 and there were many running "mules" already undergoing testing...well before actual production. And that was a clean sheet of paper engine design that was developed much quicker than typical GM engine designs because it was farmed out to Lotus. You can bet they knew the HP of the LT1 within ±10 HP in Feb, 2011.

JoesC5

Where's the proof?

Beach

I saw an ATS-V mule testing this summer. I was able to catch the car (they were flying!) and speak to the men testing it. Nothing major, but I will say this if that car had an LT1 it's the quietest 8 of alltime!!! Whoever said turbo 6 might be right.

Jinx

I'm sure that folks inside GM know a lot more than we do, and knew a lot about C7 and ATS-V many months ago.

But this is an old "article" posted on an obvious adlink-bait regurgitator website. Apply Occam's Razor -- is this more likely to be an outsider's guess from almost two years ago, or amazing insider info?


And yes, I am hopeful that GM comes to their senses and puts the LT1 in the ATS-V. Hopeful, but not expectant.

.Jinx

BlueOx

I would find it surprising if some flavor of the LT1 doesn't power the ATS-V. They could also have a TTV6 version of the ATS also.

Carver Electrics

In the pudding.

McGirk94LT1

Technically, I believe gm said build us a 400hp, dohc 350ish engine(I think the lt5 is actually a 349ci) and lotus said ok. Then when given a design gm said "no no no, it has to retain small block 4.40 bore spacing" to which I'm sure lotus engineers said a few choice words. Tons oftalk of a 400+hp vette is out there in old articles, but obviously that didn't pan out initially.

So, like, if Chevy said the lt1 will have an "estimated" 450hp, and like, this article says approximately 470hp, can I assume 510 is a safe bet?

glass slipper

Actually, GM initially said to build a set of DOHC heads for the small block Chevy but the width of the heads wouldn't fit between the frame rails of the C4 which is bottom loaded on the assembly line (the LT5 is 349.78ci or 350ci). This happened the end of '84/beginning of '85. The 400 HP number was based on an estimate given by Lotus based on the max outside dimensions of the engine. In May '85, Lotus presented the 1st drawings to GM and they noticed the 4.55" bore centers. GM imposed the arbitrary 4.4" small block bore centers (as you said) and Lotus stated they couldn't give them 400 HP...GM said they were ok with 385 HP. So while the talk was out there of 400 HP, GM knew over 4 years before production that it wasn't going to happen. You'll note that was based off of drawings, not running engines...they know very early what the HP is going to be ±10 HP in spite of what the media says. Yes, the original goal was 400 HP, GM screwed that one up with their arbitrary bore center limit.

From that May '85 meeting, the first engine was running in May '86 and the first engine was put into a test mule in Aug '86. Durability testing was completed in '87, two years before production.

The above info came from the book "The Heart of the Beast", a history of the LT5 and ZR-1.

I think the LT1 will come in at 475 HP, that's my guess.

C8forT

The rumor mill oftentimes is wrong. E.g., the rumor mill overwhelmingly anticipated that the C7 was going to have a 5.5 L motor... This rumor started when the C6-R changed to a 5.5L motor. What the rumor mill seemed to overlook is that the changes to the C6-R were mandated by rule changes in the ALMS racing series in which Corvette racing participates.

I can see why GM might want to go with a twin turbo V6. But I also can see why they might instead use the LT1. Here is my reasoning:

R&D costs - the LT1 is already designed and ready for manufacturing. The ATS-V will be a relatively low volume vehicle. The R&D costs to design a new engine for a low volume vehicle may not make sense. Yes, GM did so for the ZR1, but that is a halo car, and they used a detuned version of that motor in the CTS-V and Camaro ZL1. So, I only see them developing a twin turbo V6 if they will also use that elsewhere, for example in the next generation Camaro. That said, Camaro guys want V8s.

The ATS is built on GM’s Alpha platform. That platform was specifically designed to be able to fit a small block V8.

With cylinder deactivation, the LT1 is capable of very good gas mileage.

A V8 naturally is better balanced than a V6. Yes, many vehicles use V6s, but for a high performance motor with high output, a V8 is better.

tuxnharley

Not necessarily correct - it depends on the basic design of the engine. First order harmonics are eliminated when the number of cylinders times the degree of angle between the cylinder banks is an even multiple of 360*. A 90* V8 is 720*, thus eliminating the first order harmonics but still leaving the second order ( 2 multiples of 360*) to be dealt with.

Most V6s lately seem to be 90*, which comes out at 6 x 90* = 540*, resulting in a really messed up harmonics problem necessitating offset crank throws, bigger balancers, etc.

VW even has a 15* V6, resulting in a very narrow package for tight spaces, but a total 6 x 15* = 90* harmonics problem.

However, a 60* V6 is even smoother than a V8! 6 x 60*= 360*, thus being perfectly balanced on each (rather than every other, like a 90* V8) rotation, thus eliminating both first and second order harmonics.

Ford had some really nice 60* V6s in the Capris back in the 70s. Those engines basic design carried over into the first generation Explorers.

The problem with most V6s these days is that the manufacturers take the easy/cheap way out and "design" them by basically chopping two cylinders off of a 90* V8 block!

C8forT

I respectfully disagree. A 60 deg. V6 is better than 90 deg., but not as well balanced as a cross-plane 90 deg. V8 (or an inline 6 or flat 6).

http://www.caranddriver.com/features...angles-feature

http://en.wikipedia.org/wiki/V6_engine

From the Car and Driver article:

"A cross-plane, 90-degree V-8 has balanced rotational and reciprocating forces because it is a lot like four of the balanced 90-degree V-2s shown in the aforementioned illustration. To balance the firing force, a cylinder has to fire every time the crankshaft rotates 90 degrees. Since the bank angle is 90 degrees and the firing forces occur in 90-degree intervals, the cross-plane V-8 also manages to balance all three of the forces.

A 60-degree V-6 engine isn’t quite as successful. The rotational and reciprocating forces can’t be completely balanced because this type of V-6 is essentially two three-cylinder engines stuck together. Inline-three engines, because of their odd number of cylinders, are inherently imbalanced and will tend to rock from end to end. A flat-six engine *manages to *cancel the rocking because the opposing banks exactly cancel out each other’s motions. Putting two inline-threes together, end to end, to form an inline-six also works because each three-cylinder end of the engine exactly cancels the forces of the other. And since it’s basically two straight sixes joined at a common crank, the V-12 is naturally balanced regardless of its V angle.

But the 60-degree V-6 inherently shakes; the rocking motion of the inline-three can’t be canceled if the bank angle is smaller than 180 degrees. For that reason, many V-6s use balancing shafts, which are essentially additional crankshafts that use specifically weighted lobes to cancel out imbalance.”

PowerLabs

The new ATS-V will have a twin turbo V6 in it. This is a fact and there are test mules running around with that mill already. The very first mules used LS-3 engines for some initial validation work but that is not what the car is designed to be powered by.
GM has had their version of Ford's Ecoboost motor in the works for quite some time now.

Kappa

Yeah, I'm pretty sure the ATS-V will have the 3.6L TT V6. This is more to go against BMW and their upcoming twin turbo straight-6 M3. They will be using it in the CTS as a mid level model in a different state of tune as well.

Wouldn't be surprised if another version ended up in the Silverado/Sierra too.

BlueOx

I believe the next-gen Camaro is due to be built on the Alpha platform also.

BlueOx

Got any spy pics of that?