Creativity thrives in times of chaos and transition. Dada was born in World War I. Punk Rock arrived in the strife-torn streets of 1970s New York City. Automotive engineering– the art of bringing order to chaos– also fits this template. German automakers did some of their most innovative work in the turbulent years immediately after WWII. And now that environmental regulations and changing business conditions have upset the international automotive applecart, we’re looking at another explosion of engineering creativity. Ground zero for some of this work: the alternative propulsion experiments of the Society of Automotive Engineers (SAE) collegiate branches.
The name of this game is Challenge X – Crossover to Sustainable Mobility. The contest challenges fledgling engineers from 17 American universities to design, build and test a hybrid vehicle architecture based on a 2005 Chevrolet Equinox. They must utilize alternative fuels to reduce the vehicle's energy consumption while maintaining standard-issue performance, utility and safety.
The Challenge X’ timeline is modeled after GM’s development cycle. SAE students have four years to turn Chevy’s hunk of charcoal (sorry Equinox lovers) into an eco-friendly gem. For those readers who suffer from ADD, here are the Challenge X Cliff Notes:
Year one: teams devise theories, build models and create simulations for a new, more mpg-friendly Equinox powertrain. Year two: the judges determine which teams get the keys. The teams take delivery of their high tech kit, and attempt to install it into their prototype. Years three and four: they refine their handiwork and restore their eco-modded Equinox to “near showroom quality.”
If you think the Chevy Equinox is another forgettable CUV, you may be right. But you haven’t driven the University of Wisconsin-Madison’s Challenge X variant, christened Moovada. A Movado watch for bovines? Hey, they’re engineers (they probably don't know what I'm talking about). Speaking of which… Geek alert! If you’re not technically inclined, you might want to skip the next two paragraphs.
The Moovada is a split-parallel hybrid holstering a GM 110 kW 1.9-liter CIDI engine (found in the Fiat Punto-D) coupled to a GM F40 six-speed manual transmission. The rear axle is powered by a Ballard induction motor/gearbox powerlimited to 59 kW by the 44-module (317 volts nominal) Johnson Controls’ nickel-metal hydride hybrid battery pack. The vehicle is fueled by B20, which has a lower GHGI impact than conventional diesel fuel.
The hybrid controller is a Motorola MPC555 based Powertrain Control Module (PCM) embedded controller with 38 inputs, 28 outputs and dual CAN bus capability specifically designed for automotive applications. Wisconsin is utilizing ANSI C language for code development and MotoTron development tools for programming the controller.
Simply put, the team’s five groups (each responsible for a different vehicle system) have engineered a new powertrain package for the Equinox that delivers both fuel efficiency and entertainment. That’s right: it’s fun to drive.
Forget about the 36mpg and super-duper clean emissions. The Challenge X Equinox from the “Eat Cheese or Die” state delivers smooth and seamless power that combines golf cart-like torque with the progressive power of a diesel mill. The shifter is as wonderfully flickable as the clutch is progressive. Using Challenge X-specific Michelin tires, the Equinox not only corners with precision, it provides a quiet and comfortable ride.
Aside from the electric motor’s straight-cut cogs doing their best impression of an M-22 Rockcrusher running down the dragstrip, the Equinox behaves as well as any CUV, with a much more enjoyable powerband. Ladies and gentlemen, The University of Wisconsin-Madison team nailed it.
And now they’re perfecting it. The team is rebuilding the Moovado’s exhaust system, refining the controls system and repackaging the batteries. They’re modifying both Equinox’ interior and exterior to reflect a more "consumer acceptable" vehicle. And then, of course, there’s more testing and calibration, to assure the Moovado's performance, economy and ride quality.
Ten years ago, I was in their shoes. Back then, my team was fitting a Chrysler minivan with propane propulsion. Looking into the team members' eyes brought it all back, and puts everything in perspective. They work as a team for a common goal under a common budget. They believe in their product and their eco-friendly mission: take what GM builds and improve it for the environment– without sacrificing comfort, convenience or credibility.
Just think what these manager/creator/mentors could do at GM if the people who make cars got to “make” cars. It could happen. In these desperate days, when GM has finally realized that plug-in hybrids and other new tech could be their last, best hope for survival, GM’s engineers may once again assume their rightful place at the head of the development table.
Meanwhile, the kids are alright.
I don’t think anyone denies that Detroit does have world class engineers (but can anyone answer me how they manage to extract such little BHP from such large engines?!) but as is always the case, bureaucrats are held in higher regard.
In Detroit, their engineers will build a car with quality that people would buy and then some idiot will let an accountant loose on it. I believe that GM had hybrid technology, as well as a platform for an electric car, but because of lack of profitablity, they were shelved. Which does beg the question, if accounts at GM were responsible for making sure that GM stayed profitable (and they clearly failed at that!) then, what are they good for?
Honda is a good example of how good a company can be when engineers reclaim their throne. Henry Ford hated accountants and always made the car paramount. OK, during Henry Ford the I and II eras they did make some crap, but, at least, they did try and be bold. Strictly speaking, if accountants had their iron grip on the company at that time, we’d never have seen the Ford GT40 (a supercar which can be regarded as high as Porsche, Ferrari and Lamborghini). Henry Ford wanted a car at Le Mans and he moved heaven and earth to make sure that happened*. Try doing that now with accountants holding the company to ransom.
Toyota shows how you can let the engineers run the company but keep the accountants in the background to make sure profitablity is always in check. In fact, the majority of Toyota’s profits come from the “Lean Manufacturing” system and a engineer came up with that, not an accountant. Like someone I work with says “You can’t spell ‘Accountant’ without the words ‘A C*nt’!” :O)
I’m sorry, but I digress. The point is, as critical as I am about Detroit and I’ll admit I’m a huge import fan, Detroit does have some top engineers and if they were allowed to do their job then maybe the gap between the imports and Detroit wouldn’t be the size of Mercedes-Benz’s loss on buying then selling Chrysler Rabid Rick’s bankruptcy-proof pension.
* = For the record, Lotus did the majority of the engineering work on the Ford GT40. Typical! A British company does all the work and an American takes all the credit! ;O)
Katie,
So, in other words, “Designed by accountants, for accountants”?
I can’t understand why world class engineers would still be working at GM.
John
Katie-“(but can anyone answer me how they manage to extract such little BHP from such large engines?!)”
Every morning at GM they say a pledge of alliegence to the two-valve combustion chamber that has carried them since the 50’s.
Imagine Lance Armstrong riding up the Col Du Tourmalet with a clothes pin on his nose and breathing through a snorkel.
You have to breathe to make power, so does an IC engine.
Just a thought.
BTW-Challenge X is a great idea. Hope Detroit USES some of this creativity. How about running internal creativity challenges? What have they got to lose?
Bunter
Every morning at GM they say a pledge of alliegence to the two-valve combustion chamber that has carried them since the 50’s.
Except the LS-series V8s make tremendous power with little stress, resulting in a powerplant that’s efficient (see Corvette vs. 911 highway economy) very light (put an LS1 in a Miata and the curb weight doesn’t change) and rich in torque and HP.
I don’t buy into the flawed HP-per-Liter discussions…its all about area under the (power) curve.
I wonder how Challenge X is implemented within GM. I’m sure the Volt has plenty of stories to that effect.
Just to prove “there is nothing new under the sun” I have to share something with everyone here.
Went antique shopping with Mrs. last weekend (which, for me, means finding old car magazines).
Mechanix Illustrated, November 1977. “A car that stores its surplus power. We tried it out. Our opinion: it works!”
The language is different, but the car built and driven by a team of independent engineers – is a hydraulic hybrid which recaptured kinetic energy as it slowed down, and was also powered (via hydrostatic drive – no transmission) from an internal combustion engine.
Their “test conversion” 1977 Ford Granada (with six cylinder engine) obtained over 38 miles per gallon in a test against a conventional six cylinder 1977 Ford Granada which obtained 16 miles per gallon. The two cars were driven in tandem with precise measuring equipment.
The additional cost in 1977 money was estimated at $100 per car, about the cost of Ford’s later overdrive automatic transmission (which provided maybe a 5% MPG improvement instead of 240% improvement in mileage).
So, OK, DETROIT INC – what’s your excuse for NOT building this car?
Is it just me, or can anyone else imagine the money we WOULDN’T have sent to the middle east from oh, about 1979 through 2007, had Detroit adopted this technology?
Yep – it’s broadly similar to the hydraulic hybrid technology that UPS is slowly putting into delivery trucks right now.
I’m waiting for a response from DETROIT INC on this… waiting and waiting…. (cue the night time grasshopper sounds).
It’s because they didn’t see the profit in doing it. How come no one does anything in this country unless they get a huge payoff in the end, it’s killing us as a country. What happen to people and companies doing things just because it was the right responsible thing to do and not because it’s going to make them rich and famous.
If you ask me they are getting what they desrve right now.
From my vantage point an outsider reading messages posted here and elsewhere often by industry insiders. its all a part of the not invented here syndrome.
The constant refrain of Americans don’t want small cars, how often do you read repetitious variations of that? They only say that because they don’t like small cars.
The same type of argument has been used against hybrids. How many times do I read that hybrids are not the solution. How many times does someone pitch yet another reason why hybrids are supposedly not the solution.
I don’t know who invented the hybrid but Toyota has for all intents and purposes perfected and become synonymous with hybrids. It is my sincere belief that this fact coupled with Toyota’s public declaration that they will have full hybrid availability across their fleet, means that GM and Ford will have to be dragged kicking and screaming to the party.
For all the billions of dollars lost, thousands of employees let go, brands destroyed, market share permanently squandered and deathwatchs written, many from what I see still internally think of GM and Ford as if they are the titans of yore.
They don’t want to do, what they don’t want to do, and the fact is they don’t want to do hybrids because that would mean that Toyota is now the technological leader (they are along with Honda).
From my vantage point there is this wishful thinking that hybrids are not the solution and some Detroit based E85 scheme or some fanciful future tech that they come up with will save the day and that hybrids will be the death of Toyota’s dominance.
At least the universities don’t have those same hang ups and issues that GM and Ford seem to have following Toyota’s lead. GM and Ford in my opinion if the continue to have the hubris of refusing to see that hybrids are the future simply because the hated Toyota embraced the concept first, then they deserve to go out of business period.
“I don’t buy into the flawed HP-per-Liter discussions…its all about area under the (power) curve.”
Correct. The LS-series can pull Rosie Odonnell away from a dessert cart at 1500 RPM. Rosie could eat a Civic Si for breakfast.
KatiePuckrik:
but can anyone answer me how they manage to extract such little BHP from such large engines?!
possibly the same way honda manages to extract so little torque?
As a bean-counted engineer, I can’t believe I’m going to say this…but here goes:
Keeping an eye on the budget is important. If you let people like me run loose, you’ll have laser beams everywhere and all cars would have a thousand horsepower.
So you say Detroit can’t compete because of the bean counting? That interiors suffer because of it? So yeah, if you compare a $20,000 domestic to a $20,000 Accord, you’ll see that the “bean counted to death” interior sucks. So remove the bean counters: now you’ve got an Accord-level car that costs $30,000. How does not counting beans help the car become more competetive? It doesn’t.
If you don’t count beans, the cars are too expensive. If you do count beans, the cars are chintzy. How to rectify? Cut labor costs. Cut useless management.
Cull the herd and keep an eye on the beans.
NICKNICK,
I agree that bean counters do play a role. Please don’t misunderstand me. As I said in my previous post, Toyota is a perfect model of how Engineers and accountants can work together. However, I disagree when their roles start dictating car manufacture. Look at VW, their cars are generally 30% more expensive, but for that extra 30% you get better engineering, reliablity and a better quality car. People are willing to pay more, if they get more and that’s not even going into the realms of “resale value”.
However, in the case of GM, they’re losing market share and the bean counters are cutting budgets, to save money. Which is a false economy because all you end up with are poorer cars; that’s not going to help GM, is it? I remember an adage which I learnt on TTAC:
“On time, in budget and well made. Pick two” Unfortunately, GM and their bean counters told the engineers to do all three…..
glenn126: regenerative hydraulic power has been in use in elevators for decades. I think Ford tried it in a pick up truck too.
Sounds like KatiePuckrik is from the UK. The reason our engines need larger displacement is because we run low-octane fuel! Correct me if I’m wrong but I believe the UK uses only 93+ octane petrol? Some of our pumps serve up as low as 82 octane. If you tried to run that in your 1.6L 4-cylinder with 11:1 compression, the results would be very undesirable!
Hi Sajeev-I appreciate your input.
I agree that specific output is not the be-all and end-all.
However KatieP’s question was directed specifically to that. And I do believe that the two valve architecture is a major factor limiting the power/displacement of these engines.
The ‘vettes highway mileage is laudable but not that hard to understand. Low total drag combined with long gearing (which it can make very good use of in other ways) gives it a relatively light load and a fairly low discplacement/mile.
I’m don’t know that this demonstrates any intrinsic efficiency of the combustion chamber design. It probably is the best 2-valve, I admit.
On the other hand…
Look at the Tundra’s 5.7 vs the ‘Rado. I’ve seen 5 or 6 head to head comparisons (I’m not impressed by one test “cherry picked” data arguements)with both the 5.3 and 6.0 Chevies and in every case the Toyota was quicker and delivered better MPG. That is better efficiency.
I have observed numerous other examples of the best 4 valve engines demonstrating better power and efficiency than any available 2 valve. I really do think the two valve combustion chamber is headed out.
The flathead also had packaging advantages over the OHV engines. I think we will see the same result of efficiency over packaging/weight here. Time will tell.
Luther- That is hilarious. I think the Tundra’s i-Force can pull the Chevy AND Rosie however.
Gotta’ go folks.
TTFN
Bunter
Thanks Sajeev for this article – I’m pretty impressed with these students from Wisconsin. I’ve also been impressed by students from Pennsylvania and California who have managed to make SUVs that drive by themselves for over 100 miles in the DARPA challenge. That’s correct — no driver.
What it means to me is that there are still signs of proper engineering in the automotive arena within the US. Over the last decade, I’ve been wondering, as the CAD/CAM-station cars from the BIG 3 have fallen ever lower in innovation, and ever fuller of craprastic interiors.
Sajeev, are you saying that the aluminum LS1 V8 weighs the same as a Mazda 2 liter aluminum engine in the MX-5? Not sure I believe that. Just the crankshaft length and hence weight in the LS1 must be much more than the Mazda’s.
Steve_K. : Google Katie Puckrick. I’m highly impressed with her postings. There are few women in my experience interested in the automobile and its industry, let alone ones knowing a great deal about the subject. Also kudos to Megan Benoit for the very same reason.
And I do believe that the two valve architecture is a major factor limiting the power/displacement of these engines.
Bunter: There’s no limit, on the street or the track. The same motor goes from 5.3L to 7.0L, and you know the power numbers.
Have you seen the flow numbers of the LS7 heads? They are unbelievable, and their cheaper LS counterparts aren’t too shabby either. Tell me how many other motors make 430hp (LS3 Corvette, SUVs) 400hp (LS2 GTO) or 303hp (LS4 Impala) in similar applications. And, of course, the fat powerband you don’t get anywhere else.
in every case the Toyota was quicker and delivered better MPG.
Show me a link, but I bet most of that is from the 6-speed transmission. I haven’t driven the 5.7 Tundra yet, but if it’s as soft on the bottom end as the Ford Triton and 4.7L Tundra engines, it’s a moot point. The LS motor is one of the best trunk engines ever made.
I really do think the two valve combustion chamber is headed out.
Beg, borrow or steal a set of keys to a Corvette Z06 and you will change your tune. The only thing more amazing than its insane power at 7000rpm is its stump-pulling grunt at 1500 in that insanely tall 6th gear.
Sajeev, are you saying that the aluminum LS1 V8 weighs the same as a Mazda 2 liter aluminum engine in the MX-5?
Wmba: What year did the Miata ditch the clumsy iron block? Even with an aluminum block, the weight penalty of the LS-series is far offset by the fat powerband, just like a Shelby Cobra.
And if you try to narrow the power gap by adding a turbo/intercooler to the aluminum I-4 you narrow the weight gap and still don’t have the small-block Chevy’s ability to always be in the right gear when you exit a corner. Again, we’re talking about making a Shelby Cobra out of the stereotypical chick car with minimal changes elsewhere.
To sum it up: The 2V motor is far from dead, it kicks ass. And its proof that GM Engineers can work magic when they get the freedom to do so. They did it right…this time.
wmba:
The recent switch to an aluminum block in the 2.0L MZR shaves off roughly 45 lbs over the iron 1.8L which I am presuming Sajeev meant. I don’t have the numbers offhand, but I believe the LS1 conversion still weighs more than a turbo setup in a Miata.
Probably a better example is the RX-7. A LS1 conversion here not only weighs about the same but sits further back in the engine bay than the stock 13B-REW engine with twin turbos.
All in all, not many people realize how light the LS1 is compared to engines putting out the same power. Both the Supra 2JZ-GTE and Skyline RB26DETT weigh a couple hundred pounds more, granted they can be blown to hell and turned into dyno queens.
Have to give those students their due…they are a clever bunch. There’s enough brains around to solve GMs vehicle challenges. Management and labour challenges? We’ll see I guess.
Comparisons of engine weight is problematic, because inclusion of a more powerful engine necessitates strengthening of other components, like transmission, that will add more weight on top of the weight of the engine block.
hinsonsupercars.com, admittedly not an unbiased source, seems to report that the LS1 equipped RX7 weighs no more than a stock twin turbo setup, and the LS1 equipped Nissan 240SX weighs less than the standard 4 banger. Although I understand the Nissan KA series of iron-block I4 engines are notoriously heavy for their size. Keep in mind that the LS7, being bigger in displacement, weighs considerable less than the 5.7l LS1 (more empty space and less metal), if one of you would be kind enough to throw a LS7 into your Miata, we will have our answer.
for argument’s sake, here is a wikipedia comparison of various engines and their P/W ratios:
http://en.wikipedia.org/wiki/Pushrod
Note that the LS7 exceeds all the non-exotic naturally aspirated engines on the list with the exception of the newest 6.2l AMG V8 that I understand has been tweaked up to 525hp, although the LS still beats it for torque.
In any case, I think it’s fairly safe to say that the old turbocharged ironblock I6 engines are becoming an anachronism, as shown in the newest C class AMG and M3.
Katie: Typical! A British company does all the work and an American takes all the credit! ;O)
Them’s fightin’ words! ;)
Sajeev: great article. If anyone at the Big Three (Two.whatever) were reading this, they would be wise to hire these students. Immediately.
Sorry to double post, but I suppose I should also point out that the higher revving, flatplane, even firing German and Italian V8s have a much different “area under the slope” than our honest Detroit muscle, so even the above comparison may not be adequate.
I don’t have the numbers offhand, but I believe the LS1 conversion still weighs more than a turbo setup in a Miata.
Probably right. But the LS1 Miata will never have to wait for the turbo to spool up. I expect turbo lag would be significant on the I-4 when its boosted up enough to match the 350-ish hp you’ll get with an LS1 with zero mods.
I suppose I should also point out that the higher revving, flatplane, even firing German and Italian V8s have a much different “area under the slope” than our honest Detroit muscle, so even the above comparison may not be adequate.
No, that’s certainly fair game. The imported V8s (sans those new muscle cars from AMG) need gearing to overcome their lack of low end torque. That’s why most (almost all) can’t match the acceleration and fuel economy of a LS-V8 with a 6-speed.
And that’s why a BMW 3-series with an LS1 is such an awesome machine. VIDEO
More examples of engineering might:
LS1 Miata Video
Eat your heart out, Cobra!
One of the BMW tuner shops here in town has an E36 M3 with a rather heavily massaged LS1 shoehorned in. He says it weighs less than the stock I6, even with the beefed up tranny, and also handles better because of the lower CG. Can’t argue with the E36’s classic clean lines, and it’s nice to be able to leave most Ferraris in the dust.
Amazing what GM can do sometimes, Huh?
The Dyno Chart makes me want to….
http://www.gmperformanceparts.com/EngineShowcase/index.jsp?engId=LS7&engine=LS7&sku=17802397&engCat=ls
can anyone answer me how they manage to extract such little BHP from such large engines?
There’s no good excuse, but I guess that they had no real incentive to care. The Japanese have displacement taxes that encourage high output per liter, and most western countries have enough demand for small cars (thanks to high fuel taxes) to motivate automakers to find ways to extract more power out of engines that can fit into small packages. Americans have always had larger cars and fuel to burn, so neither fuel nor space efficiency have been priorities here. That’s a mistake that the transplants have exploited and used to their advantage.
Correct me if I’m wrong but I believe the UK uses only 93+ octane petrol?
You are partially right. The US measures octane on the AKI scale; Europe measures it on the RON scale. The numbers on the AKI scale are lower for an equivalent fuel on the RON scale.
The base octane level in Europe is 95 RON, which is equivalent to about 90 on the AKI scale. So your base level fuel in Europe is equivalent to something between mid-grade and premium fuel in the US.
can anyone answer me how they manage to extract such little BHP from such large engines?
A similar question that Honda afficiandos such as yourself could answer would be why “horsepower per litre of displacement” in this day and age is a meaningful measure of anything outside of F1 or WRC race cars? As show above, larger displacement aluminum V8 engines are both much more powerful in everyday driving AND much more fuel efficient with the correct gearing than any kind of smaller displacement, high revving engine with or without force induction. The actual difference in weight of the engines, whatever effect they may have on performance, is negligible, and as far as packaging is concerned, pushrod engines are more compact than OHC engines, and a V8 easily slips into most 4 cylinder engine bays. I think there are some minor disadvantages, such as the difficulty of incorporating variable valve timing, but solutions to that are being worked out, perhaps with completely electronic valve actuation.
So in conclusion, is there any reason why all longitudinal engined RWD cars on the roads should NOT be equipped with GM LS engines? I can’t think of any.
I’ve just remembered another reason why I hate accountants!
If it were for accountants we’d never have seen the Audi Quattro all wheel drive system. I was reading the story behind it and a group of engineers worked on this project in their spare time (it was never officially approved by Audi) because they were convinced that the theory could work. The rest as they say is history.
In fact, because of accountants’ conventional thinking, we’d never have seen the following inventions either:
The Dyson Vaccuum cleaner (The First Vaccuum Cleaner to never lose suction and total re-invent the vaccuum cleaner market.), The jet engine (Frank Whittle was told by people that it was flawed and not accounant would fund his project. He worked off his own back for 10 years before he proved that his invention worked), the clockwork radio (Accountants said while it worked, there was no market for it. It now sells by the millions in Africa and Trevor Bayliss, the inventor, is now a multi millionaire), Honda’s CVCC engine (the only engine at the time which could meet US clean air standards WITHOUT a catylitic converter, DESPITE Detroit saying it couldn’t be done without one) and Hybrid technology (My “favourite” CEO Carlos Ghosn said Hybrids are not the long term solution and diesels are more viable. Toyota and Honda took the hit and launched Hybrids at a loss. Now they make a profit on them, other are rushing their hybrids to market (sometimes leasing Toyota’s technology) and if you look at the figures, like for like, hybrids are far more efficient that diesels. Compare a Volkswagen Passat to a Toyota Prius, I think you’ll find The Toyota Prius is far better, Mr Ghosn!).
If an accountant was in charge of the construction of the Millau bridge in France, they’d have said “Look, make it big enough to cross the chasm, no bigger!”. But instead, France built the biggest suspension bridge in the world* and it really is a wonder to behold. Yes, accountants do have a role, but when we let them dictate manufacture, all we end up with are soulless, poor quality technology.
Thanks to engineers doing what engineers do best, we have technology which have contributed positively.
Rant over.
* = I should point out that although the Millau bridge is in France, guess who designed it? Yup! It was a Brit!
Probably right. But the LS1 Miata will never have to wait for the turbo to spool up. I expect turbo lag would be significant on the I-4 when its boosted up enough to match the 350-ish hp you’ll get with an LS1 with zero mods.
I agree with you entirely. Even if the weight difference is negligible, the performance and reliability of the LS1 make it the perfect transplant engine.
The actual difference in weight of the engines, whatever effect they may have on performance, is negligible, and as far as packaging is concerned, pushrod engines are more compact than OHC engines, and a V8 easily slips into most 4 cylinder engine bays.
So in conclusion, is there any reason why all longitudinal engined RWD cars on the roads should NOT be equipped with GM LS engines? I can’t think of any.
This is what I tell myself when I see the Solstice/Sky and wonder why it has a four-banger in it. Its just an LS3 and suspension tuning away from running with Ferraris and 911 turbos for about $40k.
He says it weighs less than the stock I6, even with the beefed up tranny, and also handles better because of the lower CG. Can’t argue with the E36’s classic clean lines, and it’s nice to be able to leave most Ferraris in the dust.
I’d like to get a clean E36 Bimmer for $5000, get a wrecked Camaro for $2500 and put them together. Who wouldn’t want that level of performance and polish? (evil grin)
Bunter1:
August 14th, 2007 at 12:42 pm
Every morning at GM they say a pledge of alliegence to the two-valve combustion chamber that has carried them since the 50’s.
I rarely comment here, but this one struck my eye.
Most people don’t realize that if you were to magically replace the BMW M5’s engine with the Corvette LS7 you would have a lighter car (by around 35 pounds) with the same horsepower, more torque and (likely) better fuel economy.
I think that blind bashing of GM for using “old” technology is done by people who haven’t really looked at the numbers.
“No, that’s certainly fair game. The imported V8s (sans those new muscle cars from AMG) need gearing to overcome their lack of low end torque. That’s why most (almost all) can’t match the acceleration and fuel economy of a LS-V8 with a 6-speed. ”
My BMW 540 with the 4.4 V8 makes 281 TQ at 2000 RPM, and 327 TQ at 3500. When teaching my wife to drive stick, we just kept it in 3rd all the time, even from stop :)
Hi again Sajeev-“And I do believe that the two valve architecture is a major factor limiting the power/displacement of these engines.
Bunter: There’s no limit, on the street or the track. The same motor goes from 5.3L to 7.0L, and you know the power numbers.
Have you seen the flow numbers of the LS7 heads? They are unbelievable, and their cheaper LS counterparts aren’t too shabby either. Tell me how many other motors make 430hp (LS3 Corvette, SUVs) 400hp (LS2 GTO) or 303hp (LS4 Impala) in similar applications. And, of course, the fat powerband you don’t get anywhere else.”
Are we talking past each other here friend?
Did you think I meant “power and discplacement” were limited?
I meant power for a given displacement is limited vs a four valve head. I think a survey of the engines in the market bears this out well.
I’m not sure what you mean by “similar applications”? Is anyone out side detroit building similar displacement-power engines?
Most of the 300hp and up engines on the market are smaller for a given hp. Toyota 3.5 300+ hp, 4.6 380hp (tuned for lux car).
I think that is why I focused on the Tundra’s 5.7.
Similar size and application, at the beginning of its development cycle and it seems to hand the bigger Vortec 6.0 (long into it’s refinement cycle) it’s hat and show it the door pretty well. Agree that the 6-sp trans is a factor. In mpg so is Chevies cylinder shutdown.
Perhaps if someone has the power and torque curves of both available it would prove instructive. I think you will find the i-Force very impressive.
I am not saying that there are not current applications of these engines that are viable (I do think the V-6’s are indefensible). But I do think that with similar discplacement/application engines with four valve heads entering the market they will become as irrelevant as the before mentioned v-6s. I think it would be wise if GM acted BEFORE that happened. I think the two valve is going to lose ground from here on.
Oh, no link but I do remember reading tests of the Tun und Rado in CD, MT, CR and Edmunds at the minimum. Unless memory failed the Toy was faster and more frugal in each instance.
Outta’ time.
Cheerio
Bunter
My BMW 540 with the 4.4 V8 makes 281 TQ at 2000 RPM, and 327 TQ at 3500. When teaching my wife to drive stick, we just kept it in 3rd all the time, even from stop :)
I don’t have the full powerband of the LS1 at hand, but I bet its numbers are better at those RPMs. And once you get to about 4000, there’s 350lb ft…hard to match in the BMW. Your wife would love it. :)
And you do know that a 540i with an LS1 (with the Borg Warner 6-spd to replace the ZF) will be faster, weigh less (in the nose) have a lower center of gravity, cheaper to modify and get significantly higher MPG above 60mph, right?
I meant power for a given displacement is limited vs a four valve head. I think a survey of the engines in the market bears this out well.
Unless you give me specifics on a market survey, no I don’t agree. You can push the 2v motor harder, but the LS7 is proof that its limitations aren’t from the motor, its from everything around it. Consider the constraints of clutches, transmissions, axles and govt. safety requirements. (note the BMW V10 that now has a 6-spd but has mandatory traction control to keep the driveline from falling apart)
Considering the LS7 makes 505hp from 7.0L on a mild camshaft, there’s plenty more to go. A little more cam (still street legal) will get you more like 550hp. Been done plenty of times now.
If that’s not enough power for your 2V motor, just lower the compression and supercharge. You’ll be breaking axles, smoking clutches and risking your life faster than any 4V motor could dream of.
In aftermarket trim, yes the 4V motors CAN more power in theory, but the LS7 shuts that down in the real world of automobile production.
Agree that the 6-sp trans is a factor. In mpg so is Chevies cylinder shutdown.
Perhaps if someone has the power and torque curves of both available it would prove instructive. I think you will find the i-Force very impressive.
The 6-spd improves mileage/acceleration/towing everywhere, DoD only works on the uninterrupted highway. And from my experiences with Chrysler HEMI DoD, it only works at certain speeds (55-65mph) so its benefits are quite limited in the real world.
Finding power and torque curves would be nice, getting a Tundra press truck would be nice too…but I’ll remain skeptical until I get either of them. Low End torque is King with trucks…and unless 4V I-force is significantly better than the 3V Ford Triton, I still give the 2V Vortec trucks the gold medal. :)
Its fun to talk about powertrains in such painful detail. We should make our own TTAC Challenge X car.
So yeah, if you compare a $20,000 domestic to a $20,000 Accord, you’ll see that the “bean counted to death” interior sucks. So remove the bean counters: now you’ve got an Accord-level car that costs $30,000.
If it costs GM an additional $10,000 to produce a quality vehicle interior, they’re in more trouble than I thought.
Hey Sajeev- I agree it’s been fun. I’m afraid I lack the time to keep up on this, we may just have to agree to disagree. Clearly neither of us has convinced the other but I have really appreciated your good attitude. Too often people take any difference with there vehicle choice as a personal attack.
Time will tell if I’m on to something or missing the mark.
BTW-Even at 550hp for a 7 liter the LS7 would only be at 79hp/l. That’s still mediocre four 4 valve engines. (IS 350 87hp/l, s2000 108 hp/l shoot even the LS460 is 83hp/l)
OK, I couldn’t resist one last shot!
A TTAC projectX car would be cool…as if we could ever agree on the direction to go!
Take care man.
Bunter
…and I would pose the same question to you, sir, that I did in my last post: We are comparing real world driving cars, not F1 racers with artificial displacement limits. Who cares how many hp/l your car gets? What is that figure supposed to prove? For the same engine block, more displacement means less weight, which is generally considered to be a good thing.
Nice write up Sajeev,but this is becoming commonpace with you’re journalism.You’re a stud bro.Keep up the great work.I always look forward to you’re articles.
I want in on a TTAC project-X car. You wouldn’t have to argue about 2 or 4 valves either since I have a head design that uses zero(0) tappet valves, similar to Coates Spherical Rotary valve system.
http://www.coatesengine.com/
I also have a design for a turbo/supercharge with variable boost, but that one is mostly in my head still.
Time will tell if I’m on to something or missing the mark. BTW-Even at 550hp for a 7 liter the LS7 would only be at 79hp/l. That’s still mediocre four 4 valve engines. (IS 350 87hp/l, s2000 108 hp/l shoot even the LS460 is 83hp/l)
OK, I couldn’t resist one last shot!
There’s the problem! We can’t agree when you’re still playing the HP/Liter game!
Fine for a Twingo in Tuscany, flawed for luxury or performance cars anywhere in the world. The LS7’s powerband is so much better (area under the curve) you always get what you paid for, the peak HP numbers only tell half the story.
To reiterate: don’t fall in love with peak HP/TQ figures, question the area under the curve, and never play the HP/Liter game if you’re talking about performance cars.
Nice write up Sajeev,but this is becoming commonpace with you’re journalism.You’re a stud bro.Keep up the great work.I always look forward to you’re articles.
Wow, thanks Mike! I certainly don’t do this for the fame or press cars (ha-ha), but its still nice to hear it. Thanks again!
Redbarchetta: with a name like yours I guess the project car should be a red S2000 with a Lingenfelter-tuned LS7 underhood. :-)
$5K – E36 BMW
$15K – LS7 crate engine
$5K – Shoehorn capital (cheap beer incl.)
—–
$25K – Ultimate Driving Machine
Or you could get a nicely equiped Chevy Impala.
Acually my project car was going to be my silver ’91 Alfa Spider, but the way the Cadillac is bleeding me dry I’m probably going to be forced to sell it. I would think about putting in the Northstar V8 but it’s such a POS I would rather have the barely running 121 bhp 4 cylinder. Ironic how the Italian built 4 with almost 200K miles is more reliable than the American made V8 with only 98K miles, pathetic actually.
Hi Sajeev, me again.
I think you have been missing my point.
I do understand what you are saying about hp/l and the total area under the curves (I’m an ME myself). I also see many compare similar HP engines and point at the smaller displacement 4v and conclude (erroniously i feel) that 4v engines are intrinsically weak in low end torque.
Let me try putting it a different way, I may have to finish this tomorrow so bear with me.
Start with similar displacement engines aimed at the same purpose. 3.5l 6’s for midsize cars, everyone makes one.
The best 4 valves (I assume with valve management of some sort) compared with the best 2 valves. The 4 valvers make comparable low end torque (yes I would need curves to”prove” it) demolish the 2 valves on power and have better MPG. There is no performance down side. Not about hp/l (only one of the benefits) but total engine performance.
I believe I am seeing the same with the Tundra 5.7 vs vortec 6.0 (again, proof in the curves is waiting, granted).
I am saying that if Chevy put 4 valve heads with modern timing/lift management (use pushrods if you like to keep it compact) the 6.0 in the vette it could have very similar (possibly better) low end response (torque) and far better upper end power say a peak of 500hp in similar tune to todays engine.
In similar applications with similar displacement I see the best 4v engines out performing the best 2v. This has lead to my hypothysis (yes, hypothetical) that the 2v head is outdated.
This is a simplified version of my analysis, please bear that in mind. I do bear in mind that it is unproven.
I welcome any comments you might have.
Cheerio,
Bunter
Ya know, I’d like to see what would happen if GM applied the LS7 engineering to a 2V V6 that’s about 3.5L in displacement. Maybe a little bigger if they can still get the “economy” of your average DOHC V6. After all, they seem to do well with 6.0L against 3-4L competition in the land of performance cars.
Many of your theories are sound, but in execution I doubt you’ll top the power, efficiency, packaging, etc of the 2V LS-engines in your research.
Its not that 4Vs are superior or inferior, its just that GM has found a way to make the 2V motor have no peer in power, efficiency, packaging, etc…Everyone else is trying to squeeze more powerband (not just HP) from 4v motors with variable induction, variable intake, etc. And the end result is a 2V-like powerband but with extra price, weight, complexity and often diminished reliability. (points to oil burning V-10 Bimmers as proof)
The LS-engines are proof that the KISS principle is still paramount.
And don’t forget, the OHV 2V design is more modern than a DOHC multivalve engine. About twenty years newer, if memory serves me right.
Sajeev,
Hmmm. The numbers for the v6s already look proportional to the LS engine that aren’t performance focused, and they are getting squished in economy and performance (I compared ~30 vehicles test numbers two years back, the results were GM’s MPG equal to the nissan VQ with Toy and Honda well ahead. Power? You know how that came out).
I need to challenge this statement “And the end result is a 2V-like powerband but with extra price, weight, complexity and often diminished reliability. (points to oil burning V-10 Bimmers as proof)”
The 4v engines are delivering comparable low end to the 2v without losing the specific ouput advantage they have (it is cake and eat it too time).
Packaging, yes that is true, but it does not appear to be any more critical an advantage than it was for the flathead.
Reliablilty, a single example (esp one cranking 100hp/l) is hardly relavent. I grant that in theory the complexity presents more risk. In real life the bulk of these engines are among the most reliable available from anyone.
Cost? The customers are clearly voting that they see it as providing value.
The 2v 4cylinder is dead (are there any on the market)? The 2v six is fading fast (I think the new ‘Bu is slated DOHC only).
Until recently the large 2v V8 has not really seen a direct challenge. Toyota’s first shot there has impressed most (all?) of the testers I have read as the best truck engine going, even the ones who prefered the ‘Rado overall.
I thing GM should pay very close attention. Chrysler Too.
I could go into some of the in the combustion chamber reasons I feel this change is taking place if you like. I’m short on time at the moment. A short history of 2v vs 4v as I see it.
Oh, and correct on the DOHC being earlier. Was the first in the Peugeot Bebe? I’m thinking Etorre Bugatti designed it. Memory hazy.
I have enjoyed this so far, looks like we wore out the rest. Don’t blame ’em.
Take care.
Bunter
The 2v 4cylinder is dead (are there any on the market)?
The Ford Endura E series of OHV 4 cylinders is still in production, although I believe their use is now limited to crate engines for Lotus Se7en type projects.
Until recently the large 2v V8 has not really seen a direct challenge. Toyota’s first shot there has impressed most (all?) of the testers I have read as the best truck engine going, even the ones who prefered the ‘Rado overall.
I thing GM should pay very close attention. Chrysler Too.
I don’t know about trucks, they should all have variable geometry turbo diesels as far as I’m concerned, but as it currently stands, nothing out there touches the LS7 in any meaningful performance metric, although the 6.2l AMG is getting close. When they come out with a DOHC V8 that not only matches it but is significantly superior, I’ll believe that pushrods are inferior technology like a lot of people seem to think.
Forgive me for splitting hairs, but isn’t it MBAs that deserve our disdain, rather than accountants?
I realize there is some overlap in their training, but to me an accountant is a professional specialist (or sub specialist) with deep understanding of his discipline, while an MBA has broader but shallower training.
As for Dyson, I always wonder how people can care at all about a damn vacuum. I mean, we’re talking about “hoovering” the carpet. You can get a Hoover for about $100 and it’s good enough.
Here’s a little counter-marketing to help understand why the HP / Litre discussion is meaningless:
Assuming torque (T) is measured in ft/lbs, here’s the formula: Horsepower = (T x RPM) / 5252
That’s the real deal – horsepower is actually derived from torque and RPM. What some crafty Asian folks figured out is they could alter the design of small engines so that they could achieve high RPM – and the HP / Litre “measurement” was born. Double the RPM on a low-torque I4 and you can claim double the horsepower. And they do, and people believe them.
Look at the torque curve on these engines and you’ll discover that they only produce their peak torque over a very narrow range of RPM. That RPM is usually well outside the range of normal driving, so consumers never really benefit from this “high horsepower”.
Here’s another fact: Horsepower is directly related to the maximum speed a vehicle can reach. Torque is directly related to how fast a vehicle can accelerate.
So if you’re after a vehicle with peppy acceleration but don’t care if the top speed is 130 or 150 or even 200 MPH – then the specification you should be looking at is torque, and a wide torque band is best. When you start doing this, you’ll discover that things aren’t the way the marketing people would like you to think they are.
The 4v engines are delivering comparable low end to the 2v without losing the specific ouput advantage they have (it is cake and eat it too time).
Maybe on smaller cars, but the bigger they are the more positives I see on 2V motors. Again, it boils down to dyno curves like you mentioned with the Tundra.
The Ford Endura E series of OHV 4 cylinders is still in production, although I believe their use is now limited to crate engines for Lotus Se7en type projects.
tentacles: that reminds me of a Honda buddy of mine. His early 90s Civic runs a 2v motor (forgot the code) and easily traps the quarter mile in the low 13s. His rationale? The SOHC motor has more torque, is easier to launch and costs so much less than the DOHC Integra mill that everyone thinks is so great.
I realize there is some overlap in their training, but to me an accountant is a professional specialist (or sub specialist) with deep understanding of his discipline, while an MBA has broader but shallower training.
Dynamic: I’m an MBA, and take it from me, you are misinformed. The number of engineers in my MBA classes was staggering, but not surprising. How can an Engineer move up the corporate ladder without the basics of business? MBAs come from all disciplines (English majors too) and can be extremely well rounded.
horsepower is actually derived from torque and RPM. What some crafty Asian folks figured out is they could alter the design of small engines so that they could achieve high RPM – and the HP / Litre “measurement” was born. Double the RPM on a low-torque I4 and you can claim double the horsepower.
Very well put, Whuffo. Its also the rationale for the V-10 Bimmers making 100hp more than the old V8 with the same displacement. More revving (approx 1000rpm more before redline) but less bravado below 4000rpm.
I’ve driven a couple mid-90s Civics with modified VTEC motors and they were fun. Small car, lotsa gear, lotsa revving, etc. But as cars get bigger and fatter, the HP/L smack down becomes more than a little irrelevant.
That’s the real deal – horsepower is actually derived from torque and RPM.
I’m sorry, but that’s not correct. The two measures are related, and your explanation would indicate a misunderstanding of the codependent mathematical relationship between them.
Horsepower is a function of torque and RPM, but torque is likewise a function of horsepower and RPM. You don’t have one without the other two. The formula for calculating torque is: T = (HP x 5252)/RPM. In other words, the same formula used to calculate horsepower, just inverted to calculate T instead of HP.
Double the RPM on a low-torque I4 and you can claim double the horsepower. And they do, and people believe them.
Of course they believe them, because it’s true. Horsepower is a function of both torque and RPM — not just one of them, but both. (Just as torque is a function of horsepower and RPM — it’s the same thing.)
Make a motor rev more freely, and all things being equal, you increase its power. Passenger cars benefit from emphasizing horsepower, rather than torque, because they can effectively use gearing to extract power out from the engine from the optimal points of its power curve.
The question that arises for car buyers is whether using the top of the rev range becomes unpleasant (the Honda free-revving V-TEC’s versus your GM V-8, for example.) Do people want to listen to a motor winding out at 7,000 rpm? I dunno, the ricers seem to think so…
Do people want to listen to a motor winding out at 7,000 rpm? I dunno, the ricers seem to think so…
So do the guys in the LS7-powered Corvette Z06. :)
Sorry I caught wind of this discussion late…hence the delayed response. Having a fair bit of experience with both OHV and DOHC motors, I feel the need to respond, regarding Sajeev and Bunter1’s dialogue.
Bunter1, while you are certainly correct in terms of the theoretical advantage of applying 4V technology to any existing GM 2V motor….the real question should be….why??
Let me explain: While the 4V’s ultimate flow numbers are clearly superior, esp with more conservative valve timing than a comparable OHV, there is no such thing as a free lunch. The 4V motors are physically bulkier, heavier, more complex, have a higher CG, and cost FAR more to build than a comparable 2V OHV design.
In today’s efficiency oriented marketplace, GM can slip a tidy little V6 (or even V8) torque monster in places that a DOHC V6 would be hard pressed to fit. In the sports car realm, a DOHC V8 would never fit the compact underhood dimensions of a Corvette.
And while the ultimate power/displacement numbers of a 2V are limited vs a 4V, in the real world, I think a 26 mpg 505 HP, 200 mph Corvette Z06 is already too fast for most any public road, and far more than most drivers are capable of handling. In the passenger car realm, everyone offers up 4 door sensible sedans capable of sub 7 sec 0-60 times and 140 mph top speeds….whether they use one cam or four…and (unfortunately) in America, this performance is largely academic anyway.
So for a max effort performance car…a big displacement 4V motor would be the ideal choice, but for Joe six pack out there, a low revving, durable, inexpensive to buy and maintain OHV 4 or 6 cyl makes perfect sense.
Unless we’re talking Formula 1, or Hillary tries to implement some kind of displacement tax like the Japanese have, HP/L in America is about as relevant as HP/cylinder head bolt thread count.