Predictions for NEW 2.0T engine

[dwightlooi]

I am going to make the following predictions with regard to the all new 2.0T engine that will go into the base ATS and GM mid-size vehicles based on logical assumptions of GM's priorities and available technology. Essentially, this engine will mimic the output and torque of the 3.0 liter LF1 V6 while being structured around a design philosophy that minimizes fuel consumption.

I predict that they will adopt a Turbo-Miller aspiration cycle engine built on the 2.5 liter block with thicker sleeves. The asymmetrical compression and power strokes maximizes energy recovery per unit fuel burned.

• Share the same engine block as the 2.5 liter Inline-4 with bore reduced from 88 to 86 mm
  
• 86 mm x 101 mm (bore x stroke) yielding 2347 cc static displacement
  
• Adopt a very high static compression ratio (~ 12.3:1)
  
• Very late closing intake cam profile reduces effective displacement to 2.0 liters and effective compression to ~10.5:1 (aka mild Miller Cycle)
  
• Adopt relatively low boost pressures (10~12 psi)
  
• Introduces a ball bearing cartridge dual-scroll turbocharger
  
• This engine shall be marketed as a 2.0T based on the length of its effective compression stroke (after the intake valves close) even though it is statically a 2.3 liter *
  

* This practice has a precedent in the Mazda Millenia whereby the static displacement of the engine is 3.0 liters although Mazda marketed the car as a 2.3 liter based on the length of the effective compression stroke (after intake valve closure)

Maximum Engine Speed: 6350 rpm

Estimated Power Output: 270 bhp @ 6200 rpm

Estimated Torque Output: 229 lb-ft @ 2200~6200 rpm

Estimated Fuel Economy: 23 mpg (City) / 35 mpg (Hwy) in ATS

Will find out if I am right in a few weeks...

Edited December 8, 2011 by dwightlooi

[Drew Dowdell]

well if that's the case, there's gonna need to be another engine above it to take on the 335 in torque.

[William Maley]

well if that's the case, there's gonna need to be another engine above it to take on the 335 in torque.

Couldn't GM modify the 3.6L DI V6 (ie add turbos) to take on the 335i or am I just dreaming here?

[Drew Dowdell]

I believe the 3.0 is more likely

[smk4565]

Once you build a 2.0 liter inline four, why not build a 3.0 liter inline six??? Or perhaps a 4.0 liter V8 (twin turbo). Or both.

[Robert Hall]

Once you build a 2.0 liter inline four, why not build a 3.0 liter inline six??? Or perhaps a 4.0 liter V8 (twin turbo). Or both.

That would require more investment. GM already has the 2.8, 3.0, and 3.6 V6s to reuse..

[dwightlooi]

Actually, the 2.0T will not be the product with which to go up against the 335. It will go up against the new 328 and 528 with the 240 hp 2.0T engine. The low boost formula however means that it will not match the BMW or Hyundai engines in Torque. It will however exceed them in power, linearity and fuel economy.

The 335 will be matched either with the naturally aspirated 3.6 with 315~330 hp or with a 3.0 bi-turbo with about 360 hp. The low torque 2.0T also provides a clear definition between it and the 3.6 or 3.0T.

The M3 can be matched with a naturally aspirated pushrod V8 with about ~470 hp. There is also the Bi-turbo V6 option, but getting a 3.0 or 3.6 V6 force fed to the tune of 470 hp -- essentially a Nissan VR38DETT redux -- posses higher reliability, cost and weight penalties than a small, light, large displacement pushrod V8. In the end, if past records are any indicator, there may not even be a fuel economy payback. The German retreat from V8s actually helps GM giving them the V8 luxury sport compact club all to themselves should they stick to the Small Block V8. Believe me, not everyone in C63s and V8 M3s look upon the transition to smaller displacement force induction engines positively.

Edited December 8, 2011 by dwightlooi

[dwightlooi]

Once you build a 2.0 liter inline four, why not build a 3.0 liter inline six??? Or perhaps a 4.0 liter V8 (twin turbo). Or both.

A few reasons...

• GM's Epsilon, Zeta and Alpha architectures cannot accommodate an an inline 6 -- it's too long
  
• There is already a very competitive 3.6 liter DI V6, so an inline six will be major redundancy from a positioning stand point
  
• Having an Inline 6 by itself is no guarantee to stealing BMW's business -- just look at the 1st generation IS300
  
• GM's unique strength is in highly efficient and superior performing pushrod V8 designs, they may want to capitalize on that, instead of abandoning it
  
• An Inline-4, Inline-6 and V8 have basically nothing in common from an architectural standpoint -- essentially it'll be new engine lines, hence the existence of a new turbo four engine has no bearing on the ease or cost of developing these
  

Edited December 8, 2011 by dwightlooi

[smk4565]

The Germans aren't retreating from the V8, Mercedes just came up with 2 new V8s in the past year, the 4.6 liter bi-turbo and the 5.5 liter bi-turbo AMG. Mercedes, BMW and Audi still make V12s. Plus the Germans have diesel power to big torque where needed. BMW does have the triple turbo inline six diesel on the way, rumor is that has over 500 lb-ft of torque.

E-class and up has always had V8 power, and they still do. Cadillac of the 90s had a V8 in just about everything, today it is a CTS-V and Escalade, otherwise enjoy your V6. To me, Cadillac has retreated from the V8 more than the Germans. Although the six cylinders with the technology we have now and the turbos/superchargers are almost more compelling because of the fuel economy.

[Drew Dowdell]

The LFX seems to be soft on torque down low in the rpm band and even at peak doesn't seem to match the BMW.

[smk4565]

The LFX seems to be soft on torque down low in the rpm band and even at peak doesn't seem to match the BMW.

Agreed. When I drove the CTS with the 304 hp version it felt like you really had to rev the engine, especially on hills, to feel like it was doing anything. That car needs more low end grunt. The 335i makes a lot of low end torque, even an A6 has 325 lb-ft @ 2,900 rpm, better mileage than a CTS as well.

[regfootball]

why bother if the regal GS motor already does better numbers?

[Drew Dowdell]

better numbers how? The Regal GS doesn't get 35mpg highway.

[Robert Hall]

So there is a new 2.0 T coming that is different from the current 2.0 T Ecotec? Related to the 1.4 T? i had assumed the ATS would get the same 4 that's in the Regal.

Edited December 8, 2011 by Cubical-aka-Moltar

[dwightlooi]

So there is a new 2.0 T coming that is different from the current 2.0 T Ecotec? Related to the 1.4 T? i had assumed the ATS would get the same 4 that's in the Regal.

• Yes, GM has confirmed that the ATS (and other GM products following that) will see a brand new four cylinder turbocharged engine.
  
• No, it will not be related to the 1.4T. The 1.4T block will never accommodate the expected 2.0~2.5 liter displacement, plus it currently lacks provision for DI
  
• In fact, the 1.4T itself will be replaced by a series of new 3 and 4 cylinder engines ranging from 1.0 to 1.5 liters with Direct Injection come 2013
  
• The assumption was that the ATS will get the Regal engine (LHU), but it is now confirmed that it will not.
  
• Architecturally the new engine will be based on the new 2.5 liter to see duty in the 2012 Malibu. Beyond that details are lacking.
  

[smk4565]

GM is about due for a new batch of 4-cylinders. That 2.4 liter has been around close to 10 years it seems, with just a few modest power bumps along the way.

[Drew Dowdell]

wish granted

[balthazar]

inline engines are so.... 1950. Ancient, outmoded architecture...

[dwightlooi]

OK, verdict's out. I was right on the output, wrong on the Turbo-Miller combustion cycle.

The new 2.0T will...

• 270hp @ 5,300 rpm
  
• >234 lb-ft @ 1,500 ~ 5,800 rpm
  
• 20 psi max. boost pressure w/ Air-to-air aftercooler
  
• Otto Cycle
  

No announcements yet regarding the ATS-V question... so we'll just have to wait and see if it gets the Gen V Pushrod V8 or some Bi-turbo Six.

Edited December 16, 2011 by dwightlooi

[smk4565]

I thought it had 260 lb-ft of torque?

[dwightlooi]

I thought it had 260 lb-ft of torque?

Yes, it does, but not over that wide range of rpms. Note the ">" sign...

These days, we frequently see numbers like BMW 335i's 295 lb-ft @ 1200~5000 rpm. That is NOT strictly speaking true. The 335 engine, when dynoed, does not peak until about 2800 rpm and it doesn't peak at 295 lb-ft, more like 340~360 using a 12.5~15% drive train loss conversion factor. This in part explains why 335s are faster than their specs would suggest. However, it is not that BMW is lying, at least not if you take their number to mean "at least" instead of "exactly". You see, the 335's engine does indeed make around 295 lb-ft or more from 1200 rpm to around 5000 rpm. The 1200 rpm part is hard to measure on a dyno, but it is around that much as low as you can measure. BMW advertises the 1200~5000 rpm range -- albeit at a lower torque figure -- because it appears more impressive than 350 lb-ft @ 2800 rpm.

In this case, I guess you can say that the ATS 2.0T will have about 234 by 1500 rpm and keep it above that level until a very impressive 5800 rpm -- a whopping 4300 rpm wide plateau. It will have 260 lb-ft somewhere in there; probably around the low 5000s because that is how you get to 270hp (any higher and you'll blow past 270hp, any lower and it wouldn't add up).

[Drew Dowdell]

The press release says "The 2.0T has a wide torque curve, delivering 90 percent of its peak 260 lb-ft. of torque (353 Nm) from 1,500 rpm to 5,800 rpm"

Doesn't that mean it has at least 260 lb-ft at 1,500 rpm?

[balthazar]

That means it's peak is 260, and it delivers 234 or higher between 1500 & 5800. TRQ is RPM dependant but the peak is not necc at 1500... or am I misreading your question?

[dwightlooi]

The press release says "The 2.0T has a wide torque curve, delivering 90 percent of its peak 260 lb-ft. of torque (353 Nm) from 1,500 rpm to 5,800 rpm"

Doesn't that mean it has at least 260 lb-ft at 1,500 rpm?

An engine's torque generally peaks when volumetric efficiency peaks. In turbocharged engines, this generally is when boost peaks. However, an engine ALWAYS reach a lower torque figure before it reaches a higher one. In otherwords, If an engine peaks with 260 lb-ft @ say 2500 rpm, it always reaches 90% of that before 2,500 rpm. Hence, if you are citing a range of RPMs where >= 90% of the maximum torque is made, the maximum torque is never realized at the very beginning of that range.

[smk4565]

The 335iS has even more, and I think it has an over boost to temporarily raise torque during passing maneuvers as well. But BMW's do tend to put up acceleration times better than one might think from the advertised horsepower and torque ratings. Knowing that though, Cadillac better watch their acceleration times.

[hyperv6]

The new turbo 4 engine will be at some point will go over 300 HP and torque will be over 300 FT pounds.

I see future NA 4 cyliners creaping over 200 plus HP. A 270 HP turbo would just be just an improved version of the non performance 220 HP Regal engine we have now. Unless it picks up a lot of MPG to do a 270 with only 234 FT LB as a performance engine would only be a step back. I have more than that now.

The 3.0 V6 is comimg and GM has already been free in showing for the last few years a very reliable production ready TT version with 425-430 HP in a Camaro and Holden.

The new V8 I suspect with the DI and VVT will see gains over 440-485 HP in the Vette and other applications will vary.

[loki]

hyper, i think your wording on that last one is not what you meant.

hopefully the v8's with good vvt and DI will see gains.... ~450hp+ will be a good starting point , assuming a displacement of ~6.2L like that current engine has.

in leu of that, 2 engines , say, 5.5 and 6.5L COULD be a fine place to start with replacements of the 5.3 and 6.2L....~400hp and 490hp respectively give or take depending on tuning, with as good as, or better MPG.

[Drew Dowdell]

A hope for the new Ecotecs both 2.5 and 2.0t. They fix the damn starter so it no longer sounds like a coffee can full of bolts spinning when starting up......

[dwightlooi]

A hope for the new Ecotecs both 2.5 and 2.0t. They fix the damn starter so it no longer sounds like a coffee can full of bolts spinning when starting up......

Are you sure you don't have a flex plate with a missing or bent tooth or something?

[Drew Dowdell]

Well I don't own an Ecotec, but this is from hearing even brand new ones start up. It's been too many of them sounding like that for them all to have missing starter teeth.

[hyperv6]

I find mine sounds ok. It just does not have that normal Hitachi asian car sound.

hyper, i think your wording on that last one is not what you meant.

hopefully the v8's with good vvt and DI will see gains.... ~450hp+ will be a good starting point , assuming a displacement of ~6.2L like that current engine has.

in leu of that, 2 engines , say, 5.5 and 6.5L COULD be a fine place to start with replacements of the 5.3 and 6.2L....~400hp and 490hp respectively give or take depending on tuning, with as good as, or better MPG.

Yes you got what I ment.

But while power goes up I feel the engines will move down in size. But I have been hearing that the regular Vette may be seeing power in NA form closer to the Grans Sports power now. We may see at least in the Vette form a much higher jump than many think.

[ZL-1]

This is the same engine as on the Astra OPC, right? If so I'd expect GM to not change the HP/Torque rating, even though I personally would like to see the Cadillac application set apart from the Opel one in more than engine/drivetrain layout.

[hyperv6]

This is the same engine as on the Astra OPC, right? If so I'd expect GM to not change the HP/Torque rating, even though I personally would like to see the Cadillac application set apart from the Opel one in more than engine/drivetrain layout.

GM always seems to change something in the tune so I would expect a little change. I just hope they don't detune it. This engine is not even near what it can do. I suspect Cadillac will be the first to get it with over 300 HP at some point.

[dwightlooi]

I find mine sounds ok. It just does not have that normal Hitachi asian car sound.

hyper, i think your wording on that last one is not what you meant.

hopefully the v8's with good vvt and DI will see gains.... ~450hp+ will be a good starting point , assuming a displacement of ~6.2L like that current engine has.

in leu of that, 2 engines , say, 5.5 and 6.5L COULD be a fine place to start with replacements of the 5.3 and 6.2L....~400hp and 490hp respectively give or take depending on tuning, with as good as, or better MPG.

Yes you got what I ment.

But while power goes up I feel the engines will move down in size. But I have been hearing that the regular Vette may be seeing power in NA form closer to the Grans Sports power now. We may see at least in the Vette form a much higher jump than many think.

We don't know if they'll go to a smaller displacement. What we do know is that the 5.5L displacement selected for the race cars have absolutely no bearing on the displacement of the production engines -- that was dictated by the rules.

Having said that, given that we are not changing the block size, a lower displacement V8 is not going to be lighter or smaller. It is also unlikely to be substantially more fuel efficient -- given that friction will essentially be the same while aspiration losses between a 5.5 and a 6.2 is minimal, especially with half the cylinders shut off as needed. All we know is that some form of variable timing and direct injection are confirmed. We also know that if nothing changes on the engines except the addition of AFM, DI and a 1 point bump in compression ratio, we can except about 17 mpg (City) / 28 mpg (Hwy) from a 6.2 V8 in a 3200 lbs vette -- representing a 6~7% fuel economy improvement over the current LS3. The numbers can get as high as 18/30 if the Vette sheds a couple of hundred pounds, get to a lower drag number, and/or the engines get independent VVT via a cam-in-cam setup. The 1 point compression bump also gets you ~464hp with no improvement whatsoever in any other respect of the engine (which is unlikely). Hence, an output of about 470 hp, perhaps as much as 500 hp, but no lower than 450hp should be expected. That is, in every respect, competitive with the numbers that competing DOHC V8 or Turbo V6 solutions offer.

Edited December 23, 2011 by dwightlooi

[dwightlooi]

I find mine sounds ok. It just does not have that normal Hitachi asian car sound.

hyper, i think your wording on that last one is not what you meant.

hopefully the v8's with good vvt and DI will see gains.... ~450hp+ will be a good starting point , assuming a displacement of ~6.2L like that current engine has.

in leu of that, 2 engines , say, 5.5 and 6.5L COULD be a fine place to start with replacements of the 5.3 and 6.2L....~400hp and 490hp respectively give or take depending on tuning, with as good as, or better MPG.

Yes you got what I ment.

But while power goes up I feel the engines will move down in size. But I have been hearing that the regular Vette may be seeing power in NA form closer to the Grans Sports power now. We may see at least in the Vette form a much higher jump than many think.

We don't know if they'll go to a smaller displacement. What we do know is that the 5.5L displacement selected for the race cars have absolutely no bearing on the displacement of the production engines -- that was dictated by the rules.

Having said that, given that we are not changing the block size, a lower displacement V8 is not going to be lighter or smaller. It is also unlikely to be substantially more fuel efficient -- given that friction will essentially be the same while aspiration losses between a 5.5 and a 6.2 is minimal, especially with half the cylinders shut off as needed. All we know is that some form of variable timing and direct injection are confirmed. We also know that if nothing changes on the engines except the addition of AFM, DI and a 1 point bump in compression ratio, we can except about 17 mpg (City) / 28 mpg (Hwy) from a 6.2 V8 in a 3200 lbs vette -- representing a 6~7% fuel economy improvement over the current LS3. The 1 point compression bump also gets you ~464hp with no improvement whatsoever in any other respect of the engine (which is unlikely). Hence, an output of about 470 hp, perhaps as much as 500 hp, but no lower than 450hp should be expected. That is, in every respect, competitive with the numbers that competing DOHC V8 or Turbo V6 solutions offer.

This is the same engine as on the Astra OPC, right? If so I'd expect GM to not change the HP/Torque rating, even though I personally would like to see the Cadillac application set apart from the Opel one in more than engine/drivetrain layout.

GM always seems to change something in the tune so I would expect a little change. I just hope they don't detune it. This engine is not even near what it can do. I suspect Cadillac will be the first to get it with over 300 HP at some point.

270/260 is plenty competitive; no need to push the boundaries here.

What may be interesting -- for foreign markets at least -- is a high speed 2.1 NA based on the 2.5 block. With the same 88mm pistons, but using the 2.0T crank & rod set that shortens the stroke from 101mm to 86 mm, you get a 2141 cc displacement. More importantly, assuming the same piston speed limits, you end up with a 8200 rpm redline. Such an engine will make about 220 bhp @ 8000 rpm with about 156 lb-ft @ 5000 rpm. Quite a screamer.

[67impss]

Dwight while using the same 88mm bore the pistons will be heavier because of the deck height to make up for the stroke loss. Will they be able to spin it that high? W/o forged units that would be a high load on the wrist pin boss

[dwightlooi]

Dwight while using the same 88mm bore the pistons will be heavier because of the deck height to make up for the stroke loss. Will they be able to spin it that high? W/o forged units that would be a high load on the wrist pin boss

It'll be higher than if you use light weight forged pistons, but no higher than on the 2.5 itself. The idea is to use the 2.5 pistons. The rods and crank will be 2.0T parts basically; those are forged for the turbo application. 8200 rpm is based on the same piston speeds and the same piston weight as the 2.5 @ its 7000 rpm redline.

[Drew Dowdell]

Wouldn't the rods have to be longer to make up for the stroke loss from the 2.0 crank? I may be picturing this wrong, but a shorter stroke crank with the same height pistons and same length crank would end up lowering compression? The space left in the cylinder when the piston is at TDC would be 7.5mm greater, no?

[67impss]

Either or would need be longer that is what I was trying to convey to Dwight

I've worked up home brewed strokers before

[hyperv6]

We can come up with a lot of specuations and toss around a lot of numbers but what was GM looking at?

This is where GM was looking when the money dried up. I suspect that things have not changed a lot and that the new money will be producing engines very similar in power and torque. I'm not saying this is the new engine but we can see what kind of numbers GM was working on and it should give us an idea where they were wanting to be by 2010 and later if they had not had to put many things on hold.

I do think GM should change the name Torque Curve and make it a Torque Plain. Note too the cars listed all had transmissions that would be up to task on giving more torque other than the 5 speed Kappa. That may have limited them on this version of the Eco. Today we have stronger drivelines now and coming that will take more. Note the Solstice with the LNF Turbo upgrade was given 340 FT-LBs if it has the 5 speed. This kind of Torque in a ATS would feel very welcome.

Edited December 26, 2011 by hyperv6

[Drew Dowdell]

I agree with Hyper. I doubt they would go backwards from what they already had.

[hyperv6]

I agree with Hyper. I doubt they would go backwards from what they already had.

Just on marketing alone it would be a difficult to sell a new and improved engine with less power and Torque. Even a marginal improvment would give them some brag rights.

I also expect Ford to pump more power out of the Ecoboost soon. They also have not even started to tap into what it could do.

The fact is the Ecotec is the new Small Block for the auto line up. It will be the economy engine like a 307 but it will also be the performance engine for many models like the LT1 was. The engine will be like the small block and share a design but they will come with many different internals to deal with the power they will produce.

The V6 will be the Big Block and provide the option for more of everything in the other cars. The V8 I see limited to the Corvette, Cadillac and trucks. The Camaro will keep it I feel for the next gen only in the top model but I feel it may have a limited life in the future to models like the ZL1. Ford is already to push more Eco Turbo V6 and 4 cylinder Mustangs and I suspect the V8 will also become much more limited to things like a Shelby only. That is down the road but I could see it happening by 2020 at least in the Ford.

And don't say it will not and could not work. Who ever suspected people would ever buy 100,000 F 150's with a Turbo V6 in one year at a higher price than a V8. The market and buyers are and have been shifting to new ideas of what they will buy. Higher MPG claims or not they sold a hell of a lot of trucks at a mark up and it should not go un noticed by GM.

Edited December 27, 2011 by hyperv6

[dwightlooi]

Wouldn't the rods have to be longer to make up for the stroke loss from the 2.0 crank? I may be picturing this wrong, but a shorter stroke crank with the same height pistons and same length crank would end up lowering compression? The space left in the cylinder when the piston is at TDC would be 7.5mm greater, no?

No, the stroke will not need to be longer. Combining the 2.5 pistons with the 2.0 crank gives you 2.14 liters of displacement. The crank determines the stroke length -- how much the pistons are moved. What needs to be longer is the connecting rods if you want to maintain the compression ratio (or increase it). Otherwise the pistons simply wouldn't go as high and the compression will be lower -- displacement doesn't change. Longer rods, although slightly heavier, can actually be good for high rpm durability because they reduce the side loads on the cylinder walls. When the crank pin is at 90 or 270 degrees, the longer the rod the narrower the rod angle and hence side thrust loads.

[dwightlooi]

The press release says "The 2.0T has a wide torque curve, delivering 90 percent of its peak 260 lb-ft. of torque (353 Nm) from 1,500 rpm to 5,800 rpm"

Doesn't that mean it has at least 260 lb-ft at 1,500 rpm?

GM's official site now reports 270 hp @ 5300 & 260 lb-ft @ 2400. So that settles the doubts as to when the actual peak arrives, despite 90% of it being available from 1500 to 5800 rpm.

http://media.gm.com/content/media/us/en/cadillac/news.detail.html/content/Pages/news/us/en/2012/Jan/2012_naias/cadillac/0108_ats_overview

[Drew Dowdell]

That was the point I think hyper brought up, wouldn't the 2.5 pistons start smacking off the valves?

[dwightlooi]

That was the point I think hyper brought up, wouldn't the 2.5 pistons start smacking off the valves?

Why will they? The 2.5 pistons are 88 mm wide vs 86mm wide for the 2.0. Mainly the reduction in bore in the 2.0 is to give it thcker cylinder walls.

If you bore a 2.0 out to 88mm and simply use the 2.5 pistons, the pistons are not going to travel higher or lower than in the 2.0 engiine.

If the two engines have the same deck height relative to the crank axis, it means that the 2.5 has long crank throws with shorter connecting rods, whereas the 2.0 has shorter crank throws with longer connecting rods.

[67impss]

Dwight the compression hight can be changed by the rod or piston but is normaly altered by the piston it self. In looking into the cheapest way to build a mega mouse SB Chevy I found that in using a off the shelf piston designed for a 5.850 length rod instead of a 5.7 the piston would be at deck hight with my custom stroke

And now you guys will see how bad I spell with out spell check. I've updated my Linux distribution and now as Hyper says I can't get spell check to work within the fourm outside it OK but not here. Any ideas? I'm using FoxFire maybe I'll D/L Chrome or try KDE's default. I hate looking dumb since I at least know that its spelled wrong if I see it. It's not that I'm lazy I'm dixlexic plus spelling was my worst subject I can spot incorrect spelling though and that just makes it so much worse.