BMW’s Secret 7 Series model: E32 Prototype with 6.7L V16 engine

7-series | November 2nd, 2009 by 34
v16kp4

We all can dream, can’t we? When we dream it’s said that we are projecting our inner subconscious thoughts and our deepest desires in a …

We all can dream, can’t we? When we dream it’s said that we are projecting our inner subconscious thoughts and our deepest desires in a consequence free environment. It’s those dreams that make us wake up tomorrow and explore the ideas that seemed impossible last night before we went to sleep and try and make them a reality. Well, the engineers and minds inside BMW certainly live to dream and it has never been more apparent than in regards to a said, “Secret Seven”. No, this post has nothing to do with Agent 007 and his infatuation with Bimmers, but rather an ambitious secret project involving a 7 Series by Dr. Karlhienz Lange, Adolf Fischer and Hanns-Peter Weisbarth.

All three individuals, Lange, Fischer and Weisbarth, were very senior and influential people at BMW during the mid-70′s and up through the early 90′s. Lange was responsible for powertrain developments, Fischer was involved with all obscure development projects and Weisbarth was most famously involved with the E31 8 Series coupe and E32 7 Series. It was from the mind of Lange that came the M70 5.0-liter V12 engine that was used in the 750i and the 750iL. So it only came natural that the Secret Seven project come from someone so ambitious. Lange instructed Fischer to explore the possibilities beyond the M70 engine. And it was from then that the Secret Seven project was born and BMW’s first V16 engine came into fruition.

BMWs Secret 7 Series model: E32 Prototype with 6.7L V16 engineLess than six months after Lange gave the go ahead on the project, Fischer had a complete (and production ready) 6.7 liter V16 engine on a dynamometer on Christmas Eve in 1987. Naturally the numbers on the V16 engine were nothing short of impressive boasting 408 bhp at 5200rpm and 461 ft lb of torque at 3900rpm, more than 100bhp and 100 ft lb torque than the 5.0 liter V12. Within the walls of BMW, the Secret Seven project was also known as the “Goldfish”. Reason being, the 7 Series sedan that the V16 engine was fitted into was a golden color so the project was christened the Goldfish. Now about that golden 7 series…. Naturally the addition of four more cylinders was going to cause some spacial issues when dropping into an unmodified E32 sedan. Obviously it was important for BMW to keep the modifications minimal, just in case there were ever any plans to bring the Goldfish into productions. Although no such promise existed as Lange told Fischer that although he wanted the project to be production ready, he couldn’t promise it would ever see the light of day.

BMWs Secret 7 Series model: E32 Prototype with 6.7L V16 engine

The V16 engine measured 12 inches longer than the M70 V12 that sat in the bay of the 750i. Extra space in the engine bay was nonexistent with the M70 so the addition of four extra cylinders posed a bit of a challenge. Fischer and his team of engineers did the simplest thing they possibly could and that was to move the cooling system in the E32 into the rear of the car. Naturally this method would never be employed into a production ready vehicle from BMW, let alone any other automotive company, so it was done just for sake of the Secret Seven project and to deem the impossible…. possible. With the cooling equipment in the trunk, engineers hand made custom fiberglass gills and air scoops that sat on the rear quarter panels of the car to channel cool air into the trunk. Air was expelled through a custom made valance panel that sat in between the taillights of the car, which lead to the use of smaller tail lights eliminating the rear high intensity fog and reverse lights.

The engine block of the V16 was made using high silicone aluminum with the pistons running directly inside the bores that had been etched and honed during the manufacturing process so the iron-coated pistons would run against hard silicone crystals. The V12 utilized a seven bearing forged steel crank shaft, so the V16′s crank shafted needed to be modified and utilized a nine bearing crank shaft just as the camshafts did. More modification came in the way of the engine management system. The V12 used two Bosch DME 1.2 units to run two six-cylinder engine and for the added displacement the V16 ran a more powerful Bosch DME 3.3 system that ran the engine as two inline eight-cylinder engines with the own electronically controlled throttle bodies.

BMWs Secret 7 Series model: E32 Prototype with 6.7L V16 engine

Cylinder dimensions, measured 84x75mm bore and stroke, were kept the same as the original M70 motor and raised the dimensions of the motor from 4988cc to 6651cc. Also both valve lift and timing remained the same between the V12 and V16 engines as well as the 91mm distance between the cylinder bore centers. It literally was unchanged except for the addition of four extra cylinders. Why mess with success?!? Just add onto it! One of the most exciting things about the Secret Seven project probably lies within the gearbox…. it’s a six-speed manual! The gearbox was borrowed from an 8 Series coupe due to cost and timing of the project. Numbers on the saloon were certainly impressive, boasting a 0-60 time of 6.0 seconds flat and a top speed of 175 mph.  Fuel economy, as one could imagine, wasn’t the greatest with city driving at 14 mpg and highway at 20 mpg, but this isn’t exactly a hybrid were talking about here.

In the prototype phase, the V16 was ready for full production and BMW did consider building a “Super 7″ of sorts but securing approval from the board was too far fetched and the V16 never saw a garage or driveway. As for the question if BMW will ever use a V16 engine in their lineup of large sedans? The answer is, most likely not. Reason being the economic climate and environmental consciousness of the day simple won’t allow it and would go against BMW’s “Efficient Dynamics” mantra for the present day. Unless they made a V16 hybrid…. but that would just me an oxymoron. The “Goldfish” or “Secret Seven” project is just a demonstration of some of the thinking that goes on behind the doors at BMW. Yes, there are enthusiasts behind those doors, probably thinking up more automobile bliss than one can imagine. It’s reassuring to know that BMW isn’t scared to push their engineers and designers to think beyond the standard and offer their public some of the finest automobiles on the road.

Many of us would have loved nothing more than to see the V16 make it onto the roadways, but hopefully projects like this will continue to inspire engineers and designers to always push the envelope.

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  • Mauro Corti

    Mhh impressive, but if they knew the car would not had been produced, why they continued with the project? Just for fun ? Can’t understand, but still it is simply impressive :)

  • Andrew

    Cool car! That duct work is ridiculous though. There probably was no market for a car with 16 cylinders, no trunk space and massive NACA ducts down the rear quarter panels.

  • viper

    wow….sad

  • L1ndja

    wow is exactly .

  • The Lee

    Some things are better left as concepts.

    I’m sure it would have been a blast to be on the R&D team for that car, but I’m pretty glad it never made it to a production model. That would have been an absolutely nightmare, especially considering how poorly those M70′s have weathered a bit of age over the years. I couldn’t even imagine how much worse it would have been with 4 more cylinders making 4 more combustion chambers’ worth of heat.

    • _Auday_

      Ditto

  • rider

    Great project. Sounds absolutly out of this world.Pitty it did not see production.
    If I remember correctly Weisbarth was VP Engineering at BMW of NA in the late 70′s.

  • efoza

    whatever the truth about this ‘secret’ story, let me tell you this. I saw a BMW X6M today in space grey colour. It has a 4.4L V8 engine and it is even more powerful than all 5.5L engines that I have seen and tried. So BMW has once again proven that it is not the size that matters, it is what you do with it that matters. Well done BMW.

    • Doug

      Um….. so what does this say about the v16 7′s target demographic?

    • lol

      Ok well forced induction isnt fair to compare about in a displacement discussion so your saying “its what you do with it that matters” is totally irrelevant when they just shove two turbos on it

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  • Jelle
  • http://www.facebook.com/profile.php?id=562067752 Steve Vincent

    BMW 767I what an awesome car this would have been, would have loved to have seen and driven this car.

  • Einzi.T

    i would have loved to be able to drive this car´i´m building a 757 bmw e32 with 350 chevy inside and i am almost finished so i almost have this 767 :) or it´s the closest thing i can get to this 767.

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  • http://bmwfive.com/driving/ Algis

    V16 engines are very complicated not just to manufacture but to service as well. Even in V12 engines as M70 & M73 is difficult to replace the #6 and #12 spark plugs and the starter. But I imagine V16 motor runs much more smoother as V8, not much different though as V12.

  • http://www.facebook.com/great.Cthulhoo Lukovics Péter

    a wish can never be fulfilled…a dream can never be satisfied

  • http://www.facebook.com/great.Cthulhoo Lukovics Péter

    the ULTIMATE driving machine by BMW

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  • Philip Emenike

    It is awesome drive power bespoken. A concept will oneday turn into a reality, believe it or not a generation of engineers will make it a reality. One day even V18, 14L will cruise the planes and autobhans.

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  • Sevenshot2000

    If they moved the cooling system to the rear of the car, why is the radiator still in front of the engine in the picture?

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  • STIFF

    Always Pushing the Envelope………!!!!!!! Awsome .

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  • Jorgen Lindh

    Mmm, really nice :) should have bought that car insted of a regular E32

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  • John H.

    Thinking of this engine in action made me feel like a little kid again.

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