By on July 28, 2013


Two or three times a year, Jack Roush’s Roush Collection has an open house. The Collection is the private museum where Roush keeps many of the race winning cars from what is now Roush-Fenway Racing as well as cars and artifacts from his personal collection of cars, motorcycles and airplanes (the “Cat in the Hat” must have nine lives indeed because the guy has survived two plane wrecks). Since they bring in tables for merchandise and memorabilia to sell during the open house, some of the items in the museum get moved around. Up against the back wall were a bunch of engines, race and prototype, from various projects or race cars. I was admiring one of Jack’s beloved flathead Ford V8s and nearby noticed an odd looking V4, banded to a pallet, with just a tag that said “Gemini engine” and instructions to send it to the Roush museum, with a couple of names after “Attn:”. One of the names was that of a senior Roush engineer.

Did I call it an odd looking V4? Doesn’t that belong in the Department of Redundancy Department? All V4s are kind of odd looking, at least as far as cars are concerned. The blond stepchildren of the car world (I’m a redhead). There have been a few V4 motorcycle engines, including the killer ‘half an LS’ from Katech (they also built the LS based V16 for the Cadillac Sixteen concept), but offhand outside of the Ford V4 used in Europe (and in Saabs) in the  1960s, Lancia’s narrow angle V4s from the 1920s to the 1960s, and in Murilee Martin’s beloved Zaporozhets, it’s an engine configuration that you just don’t see that often in cars or trucks.


Even for a V4 it was unusual, since it didn’t appear to have the cylinders in a common engine block, each cylinder was separate. To be honest, I thought it was a motorcycle engine and that it looked a little like the engine for the Harley Davidson VR1000 sportbike, a bike that wasn’t terribly successful but ultimately led to the creation of the H-D Revolution engine used in the V-Rod. Roush had worked on the VR1000 engine so it made sense. While processing the photos from that day, I jotted down the name of the engineer and through LinkedIn or something like it, I was able to contact him. Though coincidentally some of the people who worked on the Gemini project had also worked on the VR1000 motor at Roush, he told me that the two projects were in fact not related.

The unrelated Harley Davidson VR100 V-twin engine.

The Harley Davidson VR100 V-twin engine looks a little like the Gemini engine but the engines are not related.

Chrysler had an advanced powertrain program starting in 1989 called Liberty (unrelated to the SUV with the same name) and Roush was one of their primary contractors. That may surprise you because the name Roush is generally associated with Ford. The Roush racing teams have always raced Fords with a variety of series and sanctioning bodies and they are known for the high performance Roush Mustangs they sell. Jack Roush started out as a Ford engineer who liked to drag race, which led to having an engine shop, which he then built into an industrial empire that stretches across Livonia, Michigan. The truth is that Roush does business with all three domestic manufacturers and more than one car company that’s headquartered outside the United States. I’ve seen executive-used Fiat Abarths getting CPO level reconditioning prior to auction sale at one Roush facility and a Mazda 3 with mfg plates in the lot at the Roush Mustang build facility. At the large facility where Roush assembles (to order) the Drag Pak Challengers that compete in NHRA SuperStock with COPO Camaros and Cobra Jet Mustangs (Roush used to build the Cobra Jets in the same building but Ford now has a different contractor doing the final assembly), there was pallet upon pallet of brand new GM V6 engines, about 3,000 I was told. Apparently, GM caught a manufacturing defect, the result of one bad part, before the engines were installed in cars. Roush’s job is to take the engines apart so they can return the constituent parts back to the engine plant for reassembly.

So it’s not really a surprise that Roush has done work for Chrysler, including engine development. You may think that the Belchfire V8 (or today maybe the Hopes-And-Dreams Hybrid Drivetrain) under your hood was designed by the company whose brand is on the car but a lot of engineering work gets jobbed out to companies like Mahle, AVL, and Lotus. In Detroit, Roush gets a lot of that sort of work. For example, the engine at the heart of the Ecomotors startup may have been designed by Ecomotors engineers, but they’re developing it at a Roush facility.


Sp here’s the story: More than a decade ago, as part of their Liberty advanced drivetrain program, Chrysler contracted with Roush to work on a modular V4, essentially two V Twin modules hooked together with a clutch between them. The name Gemini came from the twin modules. The idea was to effect cylinder deactivation without the pumping and frictional loses associated with conventional variable displacement engines by completely shutting down one module. The two modules did share common coolant and lubrication systems so the shut down engine would always be at operating temperature. According to my source, the engine ran fine and met all the test criteria.

Publicly, Daimler-Chrysler CEO Dieter Zetsche praised the 50 member Liberty team, “I am always amazed at the amount of innovation this small group creates.” Privately, Daimler stepped in and essentially told the folks in Auburn Hills, “Ve haf a development team in Chermany,” and killed the Gemini project as well as the entire Liberty program. What could have the Liberty have meant for, say, the Caliber, which was certainly done no favors by its “world” engine? We’ll never know.

Ronnie Schreiber edits Cars In Depth, a realistic perspective on cars & car culture and the original 3D car site. If you found this post worthwhile, you can dig deeper at Cars In Depth. If the 3D thing freaks you out, don’t worry, all the photo and video players in use at the site have mono options. Thanks for reading – RJS

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47 Comments on “Chrysler-Roush Gemini Engine, Conceived in Auburn Hills, Born in Livonia, Killed in Stuttgart...”

  • avatar

    This is a classic… ‘What do you see when you look’ at the pic situation.

    Will read the post later and see if it jibes with what I see.

  • avatar

    That would have been an expensive motor

    I still think a decoupled system like this should and probably will be the only way for Mazda to save the rotary. 4 rotaries, each connected by clutches and dog teeth. You run 1 when you are just tooling around, and the others come on as you nee more power. I am figuring if 2 rotors can run turbine smooth one shouldn’t be far behind. And 4 will run like a V12. I am thinking smaller rotors would help counteract the combustion issue as well (huge combustion surface area). The key would be to make them combine smoothly and quickly while still keeping them in phase.

  • avatar

    Another great example of how Daimler screwed Chrysler. Yet even “car people” view Chrysler as the weak link all the while Daimler ruined MB products in their quest to build to price points. I was just at a car show in RI and saw some old school Mercedes products (and even a late 70s Malaise Era Mecuey Monarch in amazing original condition, replete with the fuel door) and you could see the quality of construction. It just oozed from the car. How anybody could look at a mid 2000’s Mercedes product say that is beyond me.

    That engine is rather interesting. Decoupling the two halves as opposed to allowing the dead cylinders to run. I wonder how much friction loss there really is? With the valves closed, the energy used to compress should be returned back on the downstroke. Is the frictional loss worth the expense and effort of he clutch setup….I guess we will never know.

    • 0 avatar


      It’s just a good example of the effective “sales job” that Daimler did in convincing people that Chrysler was a loser, plus some irrational pre-disposition people seem to have for thinking Germans are superior and infallable at everything they do. Oh, let’s not forget to add a nice ladle full of hating the home team we seem to have when it comes to our auto industry.

      • 0 avatar

        I knew the D-C merger was doomed, as the year it was announced, I was in Germany. Predictably, there was a soccer game on TV.

        The German team was sponsored by Mercedes-Benz TRUCKS. Not a Chrysler to be seen……..and this was after the US media was full of shiny happy merger talk. I asked around and the year prior Mercedes Benz CARS sponsored the team……

        uh huh…got it.

    • 0 avatar

      “How anybody could look at a mid 2000′s Mercedes product say that is beyond me.”


      Its fun to see an R-Class bring only $3-4k more than the same year Pacifica at an auction.

    • 0 avatar
      Felis Concolor

      It’s sad to realize most people still think Chrysler was the weak link in that takeover. Anyone who knew what was going on knew Daimler was frustrated they couldn’t go from concept to showroom floor in less than 5 years and needed Chryco’s expertise in rapid prototyping (<2 years from show car to showroom for the Neon; an industry record); the bags of cash on hand were simply a sweetener for the deal.

      And while we have nothing but speculation available regarding What Might Have Been for the performance aftermarket surrounding that engine, my direct experience with Mopar products knows there would have been a healthy dose of insanity in whatever packages eventually came out.

    • 0 avatar

      I worked in a company that supplied the D3 through most of the 90’s. From around ’92 until the acquisition by DB, Chrysler was generally regarded as significantly the best-managed car company in the US. It was certainly the most profitable, iirc.

      For reasons that looked like corporate politics, Jurgen Schrempp seemed keen to ditch Chrysler management and install his own loyalists. This cemented his position atop DB, but produced terrible results for the business.

      But then, DB’s aerospace business was also a disaster when Schrempp ran it. As was the decision to invest in Mitsubishi. So, it’s not like Chrysler was singled out for special treatment.

  • avatar

    So who owns the rights to this engine now? Could Roush try to sell it to another company?

  • avatar

    “Privately, Daimler stepped in and essentially told the folks in Auburn Hills, “Ve haf a development team in Chermany,” and killed the Gemini project as well as the entire Liberty program.”

    And Chrysler itself.

  • avatar

    This is a fascinating article. The concept of modular engines have been played around for a long time, and its interesting that Chrysler-Roush worked on this with the Gemini engine.

    It might be time to re-examine this technology being hybrid technology and efficient start-stop systems are now common place and relatively cheap.

    Mating an engine like this to a hybrid system would be the most ideal, the transition of starting & stopping of one set of engines could be smoothed out with a hybrid system in the middle. Moreover, more diverse set of tasks can be allocated to the second modular engine, such as charging the battery while the other set of twins run the wheels.

    There are also possibilities of an asymmetrical setup. One set of twins could be designed for highway driving with the displacement and load to be most efficient between 50-70mph under a constant load, while the other set of twins better suited for normal driving with the hybrid system for city.

    Clearly, the complexity of the hybrid transmission system would be tremendous and expensive, but if such a system can to be scalable engines in 4-6-8-and beyond become easily possible. More over, modular engines don’t need to be V-twins, they can be arranged in a U-engine config (e.g. “square-four” Suzuki RG500). Two inline-twins, or even asymmetrical inline-3 with a inline-2 mated each with individual crank shafts becomes possible with computer-controlled hybrid transmissions systems.

    Either way, I would have loved to hear what the type of lessons the engineers learned developing the Gemini engine, and what ultimately lead to getting canceled-I’m sure there were technical reasons beyond Daimler that lead to its cancellation.

  • avatar

    Thank you for this “behind the scenes” article. I find articles like this much more interesting than silly things like QOTD.

  • avatar

    Great article.

    Diamler was the AIDS of Chrysler. Rousch has a lot of contract workers working on site at the big 3, as well. The Ford ‘voice of the customer’ fleet (quality drive fleet) is all made up of Rousch employees.

  • avatar
    thats one fast cat

    “There have been a few V4 motorcycle engines, including the killer ‘half an LS’ from Katech

    AHEM. A reference to a V4 motorcycle engine and you avoid picking one of the greatest motors in all of motorcycledom? For those that ride, the engine in the Yamaha VMAX (no inline four here) would belie picking an obscure R&D project.

    But I joke. Very interesting article who knew there were things like that just laying around.

  • avatar

    Ah, no boaters in the crowd. Johnson and Evinrude dominated the Outboard Motor business with V-4s from the mid 50s. Today BRP sells a modern clean V-4 Evinrude Outboard with DI and all the modern controllers etc. That would make 60 years of V-4 Outboards.

  • avatar

    I worked at Chrysler from 1997-2007, and in jeep/truck powertrain from ’01-’07. When The Germans bought Chrysler in ’98, I remember all my retarded ass coworkers getting hyped about the ‘merger of equals’ and asking for “jurgen shrimp” in the cafeteria and shit, and these mofos were thinking everything was going to be unicorns and rainbows. By 2001 a lot of them were gone.

  • avatar

    I bought a used ’06 “Daimler Chrysler” Town & Country, with 27,000 miles, for my wife in 2008. We paid $12,000 + the trade in. Five years later, and we’re at 84,000 miles. I’ve spent a total of $2,124 on maintenance in that time. The engine’s simplicity has allowed me to do some repairs myself, and there’s no timing belt to replace. I think we’ve gotten our money’s worth so far.

    • 0 avatar

      Your ’06 was towards the end of the run of the “RS” series minivans. By then the kinks were definitely worked out and they are pretty solid vans overall. A friend of mine has an ’04 Dodge SWB with a 3.3L engine that has just about 200,000 miles on it now. His van is still on it’s original transmission, as impossible as the interwebz would have you believe that is….

    • 0 avatar

      The vans of this era weren’t too bad for reliability. My father the perpetual Chrysler minivan buyer for the last 23 years had an ’02 T&C. I also had an ’01 SWB Caravan with the 3.3L. Over the life of both of them, I replaced some small things, sway bar bushings are a common one. But never had an issue with the powertrain aside from a rear valve cover oil leak and a leaky water pump.

      The early ultra drive transmissions were low points for the vans IMO, although my dad did manage over 200k miles on the original transmission in his ’91. A 3.3/3.8L V6 model won’t give much trouble.

      Interestingly, while minivan resale is the pits no matter what, the resale for the Chrysler vans is slightly better than their competitors. The Fordstar vans speak for themselves and are lot poison, the GM vans always seem to have engine or transmission problems and everyone’s afraid of Odysseys for fear of their glass transmission.

      • 0 avatar

        My brother got 140k out of that glass transmission. Not great today, but better than most get out of it. Had his son been of driving age I don’t think that transmission would have broken 100K….the biggest weak point on his van was the sliding doors and the a/c. Repeat failures. Overall though, a good van.

  • avatar
    Kyree S. Williams

    We had a Caliber with the 2.0L GEMA engine. Aside from having a coarse exhaust note, it wasn’t bad. But they certainly could have done better…

  • avatar

    The Ford V4 was not only used in Fords and Saabs. It was also fitted to quite a number of NSU Ro80’s. Not by the factory, but by owners who get fed up with rebuilding rotary engines. The car was not quite the same after fitting the rough old Ford nail in the place of the smooth Wankel, but the V4 was cheap and it could fit into the limited space available. And it had something the Wankel never had – torque.

    • 0 avatar
      Dave W

      It was also used for stationary power. My brother went down to Ford industrial supply and got the (bolt on) intake manifold and 2BBL carb to upgrade his Sonnett to an industrial vacuum cleaner.

      I stuck with the 1BBL on mine oddly enough you could get a pinto rebuild kit that fit the SAAB carb perfectly, other then a superfluous easy to remove bit on the main gasket, that was about half the cost of the SAAB kit.

  • avatar

    So I wonder if Sergio knows about this? Would he be interested in the use of this engine, it may be better than the fours they offer now.

  • avatar

    Bash Mercedes all you like but the LX platform is amazing and it is what has been keeping Chrysler and Fiat a float. The Charger/300/Challenger/Jeep Grand Cherokee/Durango – are all vehicles that use this platform and are all recognizes as the best Chrysler has to offer.

    The Fiat based Dart OTOH has been underwhelming. I like what Fiat has done for the interiors. But its not clear their engineering is top notch at this point.

    • 0 avatar

      This probably was more of a “merger of equals” than people want to admit. Chrysler had plenty of popping head gaskets and exploding transmissions before Mercedes got involved. The crap just got more complicated after the Germans got involved.

      Having said that, there are a lot of moving parts for a late to mid 90’s Chrysler.

      • 0 avatar

        Daimler was never involved much in Chrysler’s engineering development aside from management cost cutting. Also, the LX cars are hardly a “re-skinned E-class”. There are very substantial differences, even in suspension design, especially with the second gen cars.

        • 0 avatar

          This is what I hear – but the fact remains the LX cars are a series of awesome. And everything else at Chrysler seems to be not as awesome.

          We need to see an awesome chassis out of Fiat. That would quell the skeptic. The Barracuda that’s supposed to be made from a different platform has already been delayed.

          • 0 avatar

            “This is what I hear – but the fact remains the LX cars are a series of awesome.”

            As a V8 LX car driver myself, I agree completely.

    • 0 avatar

      (a bit late to the party here, that’s what i get for having 122 tabs open…)
      the LX platform was absolutely 100% designed and developed by chrysler, almost entirely before the so called “merger” happened too. the ONLY thing that the LX platform got from mercedes was a change suspension GEOMETRY to that of the previous generation E-class. take note of that – the previous generation, not the latest generation. just like the chrysler crossfire, mercedes REFUSED to give chrysler good shit, they only gave them old, outdated garbage. the crossfire had a steering BOX instead of rack-&-pinion steering RACK for christ sake!

      as far as the grand cherokee/M-class platform sharing goes, i really don’t believe it was necessary. the GC could’ve been just as good on a “new chrysler” designed platform IMO(they’re putting out some solid vehicles right now). and the durango should’ve been on the GC WK platform way back in ’05 instead of the inferior dakota based platform.

      there is no question that chrysler benefited MASSIVELY from the old mercedes transmission though, seeing as chrysler gained quite the reputation in the ’90s for putting 50,000 mile automatics in many of their vehicles.

  • avatar

    Thanks for spotting this engine, researching it, and bringing us the story Ronnie. Nice work.

    • 0 avatar

      +1 to this and similar comments – it’s great to get that background perspective, and there’s no beating a good old “what might have been” story. Doubt there’ll be a “Who killed the Gemini V4” film, though.

    • 0 avatar

      You’re welcome, thank you and thanks to everyone else as well for the kind words.

    • 0 avatar

      Yes, RS, interesting. And thanks.

      Personally, I love the sound of a V4. For all the trends toward installing I4’s in just about every type of vehicle, I’ve always wondered why V4s weren’t built merely for the sound effect they would have over an I4. I know, cost cost cost. But for all those who install cat-back aftermarket exhausts, love the looks and performance of their sporty uni-body but long the bark of a V8…I think a V4 design would justify the extra cost.

  • avatar
    schmitt trigger

    “the Hopes-And-Dreams Hybrid Drivetrain…”

    +1, made me laugh because this is the type of name some Japanese manufacturers would seriously consider.

  • avatar

    I love hearing about aborted concept powertrains. Keep it up with stuff like this. Fascinating.

  • avatar

    Whatever happened to Ecomotor’s opposed two-cylinder motor back in 2010?

    That was designed to be modular, too, wasn’t it?

    I guess if the technology didn’t deliver, or is still under development, we’d see it on the street by now.

    Trouble is, making a successful auto engine is very difficult
    because of the demands made upon it, unlike aircraft, railroad, ship and stationary powerplants where the constant changes in loads and
    instant throttle response from a driver’s foot doesn’t occur.

    • 0 avatar

      Ecomotors recently announced that Zhongding Power is investing $200 million building a factory in the Anhui province of China to build the OPOC engine, starting volume production next year for the gen set, off-road and commercial vehicle markets. Stated capacity is 150,000 engines a year. The company still has the strong backing of Bill Gates and Vinod Khosla. I personally see no reason to be skeptical about them.

      I’m still surprised that nobody’s paid Ecomotors to build a racing version of the engine. Their CEO, Don Runkle, told me that it’d cost about $5 million to develop a racing version. It’d make a great racing motor, it has a good power to weight ratio, and has a low height, which helps with aero and keeps the center of gravity low. Actually, it’s pretty compact in all dimensions but width, but then all flat engines are wide.

  • avatar

    I need that engine for my Harley.

  • avatar

    Diamler had previous experience with a
    clutched dual engine install. See DB610.
    The results were quite illuminating during
    night ops.

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