Home » Hooniverse Asks » Currently Reading:

Defining good engineering, timing chain edition

Kamil Kaluski December 29, 2011 Hooniverse Asks 66 Comments

Hooniverse asks, part 2, slow holiday week edition.

Part of a good engineering design is the simplicity, be it in production, service, or repair. Ze Germans were always known for their mad engineering skillz, but have they recently gone overboard? Looking back at early air-cooled Volkswagens and Porsches, to much more modern  cars such as BMW E12 – E30, even E36 and E34, any E11X-W12X Benz, those cars were all well-made and well-engineered which made them robust  and easy to fix.

At what point did bling and the race for the latest and greatest technology surpass elementary engineering? Safety features aside, are modern German-engineered cars all that better than their ancestors from the 60s, 70s, and 80s? Alternately, are the modern German car better engineered than Japanese cars? In fact, have German cars ever been engineered better than Japanese cars?

I’ll finish this by throwing in the below picture. That engine is made by a company which is refusing to yield from its fundamental ways. Amazingly, decades old, that design is still relatively compact and over the years has become relatively efficient. It is also much cheaper too. In the end, my question is, which timing chain would you rather change?

  • The Professor

    Good lord, what in the world is that thing in the top picture? (Yes, yes, it's an engine). This is what happens when you design engines on a CAD system and you haven't slept for three days and the coffee has run out.
    I'll go with the standard-bastard American V8 setup, thank you.

    • Syrax

      It looks like the Audi 4.2.

      • Paul Rain

        And shockingly, it actually looks (slightly) more convoluted than the W-8's setup. Wouldn't have expected that.

        Weird, but I'd always been under the impression that cam chains damn near never needed replacement. I guess this goes downhill when you start using so much plastic you might as well have used timing gears made out of the stuff.

        • Joe Dunlap

          Youve obvously never owned or worked on old MBZ 3.5 or 4/5 engines from the 70s and 80s. Seen em wear out not only the chains but wear the sprockets down to almost no teeth left.

  • Mr. Tactful

    I was about to come back with some reply about how you're overstating how much trouble it is to service the chains on OHC engines, they never fail, you just never have to mess with them derp derp.

    But then I remembered how many times as a VW technician I had to tear down a VR6 due to lunched plastic chain guides, and how many times I had to pull the little cam link chain out of the head of a 1.8t or 2.8…due to a failed hydraulic tensioner.

    And I lastly remembered the 20+ year old Lincoln under my car port with the original chain, still doing just (apparently) fine.

    I'll be shutting up now.

    • import auto werks

      Lincoln had their chain problems too see the 3.9 (jag) V8 I have replaced a lot of secondary tensioners

    • Joe Dunlap

      You forgot to mention what you need to do to ACCESS that chain first. 🙂

  • Considering my customer base and the ease and profit level of the two jobs. Give me the lower one. Less grief, less headaches, less stress on my part and the owners. DOHC engines are always a battle of design. Add in the lack of space to do the job properly and the lower picture is a slam dunk to want to do.

    I haven't done one as complicated as the top picture but damn near close enough to it. One tooth off and you get to do the whole job over. EEK.

    Too add. Most times you'll be lucky enough to never have to do either job. By the time they are worn out most of the vehicle around it is worn out also and ready for the bone yard or winter beater status.

  • dukeisduke

    The fact that the engine is out, on the bench, speaks volumes about Audi's legendary (lack of) reliability. Read the technical details of the 4.2 40-valve (!) V8 here:

    The timing chains are on the *back* of the engine (genius, huh?), and the engine includes a *water cooled* 190 amp alternator (WTF?).

    I don't know about German engineering now versus then, but I know that my '78 Audi Fox had rear drum brakes that weren't self-adjusting, whereas American cars had been using self-adjusting brakes since at least the '60s.

    • The Professor

      The timing chains are on the back of the engine? Someone needs to make the designing genius that came up with this setup change the chain(s) while being encouraged by a cattleprod. Then taken out back and severely beaten, then rubbed with salt.
      And what on Earth would you need a 190 amp alternator for? I'm genuinely curious.

      • Mike_the_Dog

        HID headlights? God knows the LEDs don't need much juice.

        • dukeisduke

          HIDs wouldn't even need that. They use ballasts to kick off the arc. I know that some Ford Super Duty tucks run 190A alternators, but that's so they can supply juice for commercial applications, like ambulance equipment.

          • ptschett

            Big farm tractors and combines these days have alternators in the 200A range too, but of course these are things that have more headlight wattage pointed rearward than most road vehicles have pointed forward.

            • Joe Dunlap

              Meh, 200 amps? Check out the specs for the water cooled monster on a VW Touareg V-10. Hint: For starters it needs to service 2 batteries.

      • Hey, if rearward timing chains are good enough for the Citroën SM….

        As for the water-cooled alternator, I'm reminded of the combination generator-water pump on bullnose two-stroke SAABs:

        <img src="http://www.saabisti.fi/wp-content/uploads/2009/04/waterpump_0027.jpg&quot; width="300">

        The shaft seal between the two sections is water-lubricated. What could possibly go wrong?

        • The Professor

          A combined alternator and water pump? Nothing like pushing your luck, I guess. And we still wonder why Saab went tits-up…

          • No, it's a generator (or, for Rusty's benefit, a dynamo). Perfectly safe. They'd have been crazy to try that with an alternator, as it would have kept messing up the polarity of the coolant.

            • Devin

              But as low budget science fiction tells me, reversing the polarity makes everything work better.

      • Do these cars have electric power steering? Electric air conditioning pump? I can't think of anything else that would require that much power.

    • IIRC, my Phaeton's 4.2 liter 40 valver is based on this engine. Just imagine the hell of working on the W12 48 valver!

    • On the plus side, it looks like the only two chains that are timing-critical are on the top of the stack…?

  • Cherokee Owner

    Personal realization: I'm not a wrench, never cracked open a engine block, and never really been a GM fan…

    …but I knew that bottom pic was a LS engine timing chain before I googled "GM LS timing chain" to make sure.

  • TurboBrick

    I'm starting to think that car engineering is becoming more like airplane engineering. Complicated technical solutions that require X-amount of maintenance after XX hours of operation, and more than likely the powerplant has to come out of it's cave to do that. The chains seem to last a long time but it's always the guides that go bad. I'll still prefer my red block with a rubber band and a single spring-operated tensioner, won't break your bank even if you swap both every 50K.

  • Here are some factoids about the VW Phaeton's two batteries. One is for starting, the other is for the accessories.
    1. If the starter battery has been depleted, the accessories battery will work in conjunction with the starter battery.
    2. At 10 degrees C or below, the batteries will work together to start the car.
    3. Right after a hard collision, an explosive charge will disconnect the starter battery at the positive terminal.

    • 3. just became my explanation for a no-start condition on anything that comes in the door.

    • The Professor

      An explosive charge right after a hard impact? Er…what if there is fuel around? And what do they classify as a 'hard' collision? That sounds like it could really be a pain in the ass.

      • Joe Dunlap

        The explosive charge (and its a tiny one) is contained inside a plastic housing. Under the trunk floor, behind the interior panel. It deploys on signal from the airbag module, so virtually no chance of igniting any fuel. It happens before the crash is even finished.

        • The Professor

          Ah, that's good to hear. You expect it to be done properly, then they'll turn around and produce something like that Audi engine up top, and you wonder if they are even sane.

    • Matt

      So VW has actually been designing cars that blow up on their own intentionally? I knew it all along.

      • These newer VWs are over-engineered. The simpler solution in the original Bugs was to put the battery under the rear seat, with no meaningful protection of the top-mounted terminals:

        <img src="http://www.reluctantmechanic.com/images/back-seat-up_big.jpg&quot; width="300">

        A heavy load on the seat will force the springs downward into contact, causing sparks to fly directly into the dry sisal seat padding. Instant fire! Easy as that.

        • buzzboy7

          Stock VW batteries were side terminal for that reason IIRC.

          my vw had a piece of cardboard.

          • Mine (a '74 and a '77) took batteries with the positive top post protected by a goofy little "picnic table" piece of plastic with spindly legs that fit into holes in the case. The arrangement did not inspire confidence. Sort of like what's shown in this '67, but with provisions for only one terminal to be "protected."

            <img src="http://farm4.staticflickr.com/3407/3412499255_2bd6ae859c.jpg&quot; width="400">

            • The Professor

              I remember those tables. The mechanics at the Mercedes shop where I worked would lose them before they got back to their bench when they were installing a new battery. I kept a box of them under the counter in case anyone needed one, but I don't remember any takers. M-Bs didn't really need them anyway.

  • MrHowser

    Sorry for the ignorance, but what is the second picture? Small block Chevy?

    • jeepjeff

      Specifically a recent LS block. As the article implies, it is still in production, which means it's either an LS or a Hemi, and the LS is more iconic. (It has to be a pushrod engine because that's the only way that timing chain setup works.)

      (EDIT: I'm a big fan of pushrods. I have an example of the last production pushrod I6, well, at least for the NA market. It's wonderful and I love it dearly.)

      • The Professor

        That's right, they stopped making 454s didn't they? Pity, I like mine.

        • jeepjeff

          The Viper V10 was another pushrod hold out, but it is out of production too. With any luck, they'll make a pushrod V12 Hemi for the new one. (A boy can hope, right?)

  • Scandinavian Flick

    Excuse me while I go out to the parking lot to hug my LS2…

    Okay, with that out of the way: Seriously, what is up with making engines and supporting components so hard to work on with modern cars? I understand the need for continual "improvement" and added features. Nobody would buy new cars if car companies didn't do that. But is it that hard to make it more physically easy to service? Making it this difficult passes on higher maintenance costs to the consumer. It makes it not worth it to maintain your car, since it would actually be cheaper to make payments on a newer…

    …wait… I see what they did there…

    • topdeadcentre

      My guess is that parts sales for the manufacturers, and after-warranty repairs for the dealers, makes all kinds of nice profit that they can't make on car sales anymore.

    • Paul Rain

      While all car companies would love to make higher margin more disposable products, the real reason has been to comply with the ever more arbitrary regulations imposed on them over the years. An engine bay you can stand inside might be nice and convenient, but the more space GM gives you to work on things for a given amount of structural rigidity, the more weight the car will carry. More weight, and they can't keep up with fuel economy regulations being ever-ratcheted up.

      Meanwhile, you can't even sell a lawnmower in California without CARB certifying that ze idle speed and ze mix may not be adjusted outside der set limits.

  • XRSevin

    Since for me the question is "which one would you like to pay someone else to change?", it appears that my long-held belief that you never want to be the second owner of a German car has a basis in reality. A friend of mine is selling his father's babied one-owner 928 for him. It's an under $10,000 supercar and I don't want to even look at it in person. There's too much "Blue Angel" in used German cars; they are the siren that will ruin your life.
    <img src="http://www.u.arizona.edu/~chisholm/GER588_files/marlene_der_blaue_engel.jpg&quot; width="600">


  • If there's one thing I've learned working for an auto parts distributor for the past 9 years, it's to never ever consider buying a late model VW/Audi product.

    My friend works for Alldata and for a while was working on VW repair procedures. It takes 8!! hours to change the oxygen sensor on a W8 Passat.

    • Fwha? Isn't that the one that screws into a bung on the exhaust pipe? Unplug the wire, torque it out, put in new one, reinstall plug, done. What did VW do to make that take 8 hours, install it on the underside of the exhaust manifold?

      • PotbellyJoe

        I think you actually have to take the engine out for one of the 4.

        • Joe Dunlap

          Thats what VW originally stated for tech time on warranty repairs. They dropped it down to 3 when they found out some sharp techs were able to do it in 2. But yeah, they were in an unbelievably bad place.

  • Jim-Bob

    I think people tend to overstate the quality of German engineering. While it is true that they have built some very good vehicles over the years (OM-617 anyone?), the vast majority of their more recent work has been anything but well thought out. This is not to say that they do not perform wonderfully when they work right. The problem comes when it is time to service them. To me, a well-engineered car is designed in such a way as to be logical to service and to need minimal maintenance over the long term. The Germans seem to forget this and build cars that are expensive to keep running and whose components are arrayed in such a way as to require an almost complete teardown of the car in order to do something as simple as changing a thermostat. Sorry but when I think of well-engineered cars I generally think of something Japanese. Not all of them are well designed but most of them are. The only issue with the Japanese as of late is that they seem to have forgotten how to design a regular car that is also fun to drive hard. However, given the choice between say a Volkswagen Jetta and a Toyota Corolla I would probably take the Toyota. I simply can't afford to drive a basic family car with a lackluster warranty and Porsche levels of maintenance costs.

  • I'm starting to believe that all cars of the last ten years should be ploughed into landfill. With the new responsibilities of home-ownership and all the fiscal hardship that comes with it, the last thing I want is to have to pay somebody to twirl wrenches.

    I'm of the opinion that, when my current fleet kicks the bucket, I might just head out and find something with pushrods and a carburettor. And, alas, it probably won't be a V8.

    • Jim-Bob

      They probably will be. I almost think that the brutal levels of complexity are there to bring about sort of a planned obsolescence. This is also supported by the lack of paper service manuals for models from the last 10 years. Instead, they require you to subscribe to a expensive service that few individual owners can realistically afford. Thus, when the warranty runs out and it starts to become troublesome, it goes to the scrap yard rather than to someone who is adept at fixing things and can keep it running for another 10 years on salvaged parts and "free" labor. This makes purchasing a new car every 3-5 years and trading it when it runs out of warranty the fiscally prudent thing to do and builds the customer base for the manufacturers and finance companies.

      • dukeisduke

        I could order the Toyota service manuals for my '08 Sienna, but the three volume set runs about $420, and it's another 100 bucks for the wiring diagram manual. Ugh.

        I spent around $400 for all the manuals for my '95 F-150 – powertrain/drivetrain, PC/ED (OBD-I – I had to buy for the whole '95 Ford/Lincoln/Mercury line, OBD-I and OBD-II), and EVTM.

        • Jim-Bob

          For older models, E-Bay is your friend. I got the complete 4 piece set (mechanical, wiring, and supplements inc. tsb's) for my 1991 Metro for $30 with shipping. They were used but in very good shape. I have done this for all of my vehicles (and spent $20-50 for them) as nothing beats a FSM for detail.

          As for the Sienna, I am happy to hear that they sell them. When I was researching the 2010 Yaris as a possible new car I read that they did not sell them and instead required you to do the subscription thing. It was one of the reasons I decided against buying a new car and got the Geo Metros instead.

  • txzman

    Looks exactly like the type of engineering the killed the Leopard Tank and most other hig-end designs for the Germans in WWII.. Great performance at the expense of completely over-engineered and high-maintenance requirements that made the end product beautiful to look at but an impossible nightmare to take care of.

  • smokyburnout

    It really is convoluted. Why not move some of the timing gear to the other side of the engine?
    <img src="http://dione.geophys.nat.tu-bs.de:5214/dragos/public/R75/kv6.jpg&quot; width="600">
    IMG from MG-Rover.org

  • Chain driven camshafts or gear driven camshafts that is the question.

    <img src="http://www.oldstox.com/images/Bristol%20Hercules%20sleeve.gif&quot; >

    • And straight-cut, too! I'd be amazed if you could hear the engine over the valvetrain noise.

    • The Professor

      Sheesh, I've seen simpler mechanical watches.

  • There's simple design, then there's sophisticated design, and then finally there's byzantine design. Simple design is embraced by believers in the 80/20 principle, and those who value rugged design and ease of use above all else. Sophisticated design is the other side of that coin, where a designer does what it takes to extract that last 20 percent, and accepts that some additional complexity will be required. There's a sort of elegance to both approaches, and more often than not they overlap in places.

    Finally, there's byzantine design, where somebody looks at the extra complexity that a sophisticated design has over a simple one, decides that if some is good, then more must be better, and craps out the monstrosity seen at the top of the page.

  • suju89

    What do you mean I need to drop the transmission to change the thermostat?

    <img src="http://www.webwombat.com.au/motoring/news_reports/images/alloytec2.JPG"&gt;

  • buzzboy7

    No chains, no belts, just good old gear on gear action.
    <img src="http://classicvw.org/gallery2/d/1515-2/cam_install.jpg&quot; width="500">

  • corytate

    vq37 is pretty close to being as fun as the first engine. lol.
    not to mention the fact that if you have a problem with the VVEL ladder you have to replace the entire head.

  • ptschett

    From personal experience, something in between works for at least 192k miles. (I've been spending this week getting reacquainted with my '96 Thunderbird… AFAIK it's never had the valve covers or timing cover off.)

    <img src="http://www.modulardepot.com/images/med_timing_7.jpg&quot; width="500">
    Image from modulardepot.com

  • H88

    As I ranted about this in my blog some time ago ( http://thecarhobby.blogspot.com/2011/10/rant-abou… ) , it really makes you think twice about keeping these cars long term. At least not without budgeting large sums of money for service. The problem arises when the cost of what appears to be "simple" repairs starts to approach the market value of a vehicle that is otherwise in good shape. It is clear the goal was to stuff these large engines into ever smaller engine bays just to sell more cars. Ease of service was obviously not a design parameter nor was longevity in some cases.

  • Deartháir

    Yup, I could have predicted that the comment thread would have gone that way, when the question is as horribly leading as that one is.

  • Van_Sarockin

    Engineering is about doing more with less. Simple is often very sophisticated, while it's easy to stick things on. But there are also some very good reasons we don't often use rocks as hammers anymore.