Hello, Allpar Forums member or visitor! If you were a member, you would not see this ad!

Register or log in at the top right of the page...

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

The return of the inline 6

Discussion in 'Auto News & Rumors' started by Fast Eddie, Oct 24, 2017.

  1. Fast Eddie

    Fast Eddie Valued Member
    Level III Supporter

    Joined:
    Jun 12, 2014
    Messages:
    1,471
    Likes:
    1,307
    [​IMG]

    AUTOMOTIVE NEWS ARTICLE
    Nearly 70 years since it was blown away by the high-compression Oldsmobile Rocket V8, the inline-six engine is poised to make a comeback.

    I'm not the first to connect these dots, but the reason for the return of the inline-six has everything to do with manufacturing efficiency and not because of an inherent fault of the V-6. As V-8s fade away, the V-6s they spawned will also diminish in numbers.

    BMW, which never abandoned the inline-six, has created the template for the modern modular inline engine family that other automakers are adopting. At BMW, each cylinder is 500cc and the engines are modular, meaning that they use the same basic menu of internal parts, such as valves, pistons, bearings and pumps.

    "The advent of the modular 500cc cylinder has brought us a flurry of 2.0-liter I-4 engines, 3.0-liter V-6 engines and 4.0-liter V-8s. A lot of this was due to cost," says AutoPacific analyst Dave Sullivan. "Being able to use the same hardware in multiple applications helps to bring costs down. The inline-six is naturally harmonically balanced, reducing the need for balancers or any expensive treatment systems," he added.

    When Jaguar Land Rover developed its acclaimed Ingenium gasoline and diesel engine family, it used BMW's 500cc per-cylinder and modular component strategy, but with engineering twists of its own. JLR's announcement last month that it plans to stop buying gasoline engines from Ford's Welsh engine plant in 2020, opens the door to larger Ingenium engines. JLR officials won't confirm six-cylinder Ingeniums are on the way, but it is a sure bet they are.

    JLR buys its V-8 and V-6 engines from Ford, and without those engines, it would have only turbo four and hybrid vehicles -- which would not develop enough torque to provide the kind of performance a Range Rover needs to take on Bentley and others. But a supercharged 3.0-liter Ingenium six could easily replace the 5.0-liter V-8.

    JLR's plan to halt the Ford V-6 and V-8 gasoline engine purchases in 2020 indicates the six-cylinder Ingenium engine will likely be ready for the 2021 model year -- or sooner if JLR discontinues the V-6 before the V-8.

    As three- and four-cylinder engines continue to deliver more power and efficiency, it's far less expensive and disruptive to add another pair of cylinders for a bigger engine with more torque than to build a V-6 that doesn't share its parts with a V-8.

    Mercedes' new inline-six, a 3.0-liter, comes in two flavors, Automotive News affiliate Autoweekreports, including one that cranks out 435 hp.

    But there are problems related to inline-sixes. Most are longer than the V-6s they will replace, making it tough to mount the engine in front-wheel-drive cars because the engine's length leaves little room for the transmission. That length also can be problematic for rear-wheel-drive cars, which may need longer hoods to accommodate the engine.

    And then there's safety.

    Engineers appear close to solving a few lingering safety problems that they didn't have to deal with when a V-6 was installed. "One of the long-standing issues [for the inline-six] has involved the length of the engine and crash standards. It appears that manufacturers are confident they can have an engine 'deform' and not penetrate the cabin," says Sullivan.

    But, if you've driven a BMW six lately, you know how smooth and silky an inline-six can be. Now, with direct injection, variable valve timing, electric superchargers and electrification, the inline-six just may be the configuration that propels the internal combustion engine to the finish line.
     
  2. ScramFan

    Level III Supporter

    Joined:
    May 21, 2006
    Messages:
    92
    Likes:
    100
    I would also think that having the exhaust on one side of the engine greatly simplifies turbo charging, and with electric turbos due imminently, I bet not having to have 2 of those units is particularly important.

    Just a guess, but I really think the prevalence of turbos is a major driver of this move back to I6's.
     
  3. voiceofstl

    voiceofstl Well-Known Member

    Joined:
    Jan 15, 2010
    Messages:
    888
    Likes:
    293
    Why did GM invest million in the Atlas engine line that had the straight 6,5,4 and then droped it?
     
  4. Muther

    Muther Well-Known Member

    Joined:
    Mar 23, 2012
    Messages:
    3,581
    Likes:
    3,063
    On the assembly line, I believe building an in-line engine (one head) is much simpler and cost effective than building a Vee (two headed) engine. Simply because the engine has only one head.

    So, in this case, two heads ARE NOT better than one.
     
    superduckie5000, Bearhawke and pt006 like this.
  5. GLHS60

    GLHS60 Well-Known Member

    Joined:
    Jun 23, 2008
    Messages:
    1,390
    Likes:
    372
    I recently saw Jack Roush interviewed on TV and he is developing an inline 6 for use in space!!

    He claimed he prefered a V8 but NASA insisted on a six.

    Hard to believe an I.C. Engine has a role in space travel!!.

    Thanks
    Randy
     
    12soldier likes this.
  6. Stéphane Dumas

    Stéphane Dumas Well-Known Member

    Joined:
    Jan 20, 2002
    Messages:
    2,891
    Likes:
    205
    If BMW had switched to V6, would some folks had saw them as a sign of the Apocalypse? :D

    Could we dream of a new Hemi 6 this time available in North America? Imagine a Charger SRT-Hemi 6 Pack.
     
    Fast Eddie likes this.
  7. jimboy

    jimboy Well-Known Member

    Joined:
    Dec 7, 2006
    Messages:
    911
    Likes:
    621
    One can certainly see the value of an inline six as a sporting application, such as A.R., Mas., Charger/Challenger, and as a luxury/performance ride for Chrysler. I think we will see the V-8 all disappearing the not too distant future except in High performance/High cost vehicles. The I-6 is a better alternative than a V-6, IMO.
     
  8. LouJC

    LouJC Active Member

    Joined:
    Oct 7, 2014
    Messages:
    520
    Likes:
    370
    I never stopped liking them, and there was a lot of potential in the old AMC/Jeep 4.0 that was never realized. After driving a '98 Grand with the 4.0 for close to 20 years, I can say that while the new Pentastar in the Wrangler 051.JPG has great top end power, the low end on the old 4.0 still feels better!
     
  9. page2171

    Level 2 Supporter

    Joined:
    Apr 28, 2007
    Messages:
    576
    Likes:
    657
    I wonder what the 4.0 would be like if it was backed up by one of the new transmissions, like the 8 speed they are using now.
     
  10. LouJC

    LouJC Active Member

    Joined:
    Oct 7, 2014
    Messages:
    520
    Likes:
    370
    I would have liked to see it re-engineered with a crossflow head and a modern transmission. The old Chrysler 42-RE was basically an old school Torqueflite with an added on overdrive and electronic governor. Even the Chrysler electronic 5 speed in my '07 is much more responsive. These engines were tough and can easily reach 200,000 miles. All cast iron and 7 main bearings.
     
  11. 77 Monaco Brougham

    77 Monaco Brougham Active Member

    Joined:
    Jan 15, 2017
    Messages:
    683
    Likes:
    985
    Speaking of dreams......

    Dare we dream of an electrically turbocharged Hemi Inline-8 for use in a future Dodge "Halo Car / Successor to Viper"?
     
  12. LouJC

    LouJC Active Member

    Joined:
    Oct 7, 2014
    Messages:
    520
    Likes:
    370
    As far as V6s, I am partial to the Chevy 4.3 V6 in our old '88 Four Winns boat. These are also tough engines, long lived and easy to repair. You can see the advantage of the V6 in packaging because they are quite short, although just as wide as a V8. Here it is after a top end overhaul with a set of reman heads and all new gaskets. 30 years old, used at least half of that in salt water.....Very simple to work on, I was able to do all of it myself.
    IMG_2235.JPG
     
  13. Erik Latranyi

    Level III Supporter

    Joined:
    Aug 20, 2003
    Messages:
    10,824
    Likes:
    10,167
    Folks, the 4.0 Inline 6 could not meet emissions standards and could not be upgraded. Chrysler knew its popularity, but had no choice but to meet government regulations and end that engine.

    So, please put all the wet dreams away. The 4.0 was a great engine. Let it's legacy live on and stop trying to bring the dead back to life.

    None of the new inline engines will ever be as good.
     
    danbek and ehaase like this.
  14. T_690

    T_690 Active Member

    Joined:
    Aug 31, 2015
    Messages:
    1,200
    Likes:
    1,342

    BMW had a lot of issues with turbocharged Inline 6 engines. So far their turbo 4 is much better, much less issues.

    But technically V6 should be superior performance engine. I did not say that V6 is a better daily driver.
     
  15. link3721

    link3721 Yes, This MK Goes Off-Road
    Level 2 Supporter

    Joined:
    Oct 18, 2012
    Messages:
    928
    Likes:
    619
    Why not? It's been over a decade since the 4.0 was installed in a new vehicle. I'd imagine a modern I6 is MORE likely to be a better engine than the old 4.0.
     
    djsamuel and T_690 like this.
  16. Erik Latranyi

    Level III Supporter

    Joined:
    Aug 20, 2003
    Messages:
    10,824
    Likes:
    10,167
    The reliability of the old 4.0 I-6 will be hard to be matched due to today's cost-conscious efforts
     
  17. T_690

    T_690 Active Member

    Joined:
    Aug 31, 2015
    Messages:
    1,200
    Likes:
    1,342
    Everyone could reach reliability with that power density. It's not a question.
     
    djsamuel and ScramFan like this.
  18. link3721

    link3721 Yes, This MK Goes Off-Road
    Level 2 Supporter

    Joined:
    Oct 18, 2012
    Messages:
    928
    Likes:
    619
    I think that modern technologies are what will allow engines to be that reliable while also being cost effective. I generally don't hear of reliability issues with modern engines, it's usually other parts that are now apt to be the weak link of a vehicle's overall reliability.
     
    ScramFan likes this.
  19. pt006

    pt006 Active Member

    Joined:
    Dec 24, 2014
    Messages:
    1,284
    Likes:
    491
    I agree with the assembly and turbo reasons. The down side of a straight 6 is the weight of the crankshaft and the larger machinery that is required for the head/pan surfaces and the line boring of the head and block. A straight 6 works well in big diesel trucks.
     
  20. AC TC

    AC TC Well-Known Member

    Joined:
    Dec 3, 2004
    Messages:
    2,520
    Likes:
    347
    There are numerous disadvantages mechanically for the straight six.
    - longer, read more flexing block- making it stiffer makes it heavier.
    - heads..the same as above.
    - crank...again the same.
    - larger gaskets for head and pan, harder to get it sealed.
    - the engine is long and that cant be done in any other way, give packaging problems.
    Now why do they survive and strive in big diesel trucks?
    - they fits very well chassis wise.
    - weight isn't a big problem.
    - they usually have separate heads.

    And to pour some gas in here...
    - I belive that the pentastar v6 out torq ( at any rpm ) and have a longer lifespan than both the jeep i6 and the leaning tower of power...
    - also suspects that it have lower NVH numbers than these..
    - put a low rpm charging turbo on it and it will outperform the hemi, not counting the hellcat..
     
    somber, link3721 and wtxiceman like this.

Share This Page

Loading...