Rünge's Flat-8 Engine Is a Generational ProjectRünge CarsIf you're not already familiar with the work that takes place at Rünge Cars in Alexandria, Minnesota, you're doing yourself a disservice. The small outfit specializes in traditional coachbuilding techniques, working with customers to craft each vehicle in hand-formed panels draped over a bespoke tube-frame chassis, all made from aluminum. The vehicles themselves are masterpieces to behold—ones borrowing a bit of inspiration from a particular Stuttgart-based automaker.Rünge don't just craft bodywork, however. The company produces nearly every major component of the car themselves. For the brand's upcoming flat-8 engine, input has come in from two generations of Rünge men. Founder Christopher Rünge explained to Road & Track how his son Fin has helped transform his workflow and outlook with a bit of modern automotive technology.While Porsche proved the effectiveness of the flat-8 engine in its racing cars from the 1960s, the brand never stuck one into a series production car. Rünge has long been fascinated by what could have been. He was ultimately approached by a customer in 2017 who was interested in building an eight-cylinder based on "twin" 356 motors, but the project ultimately never came to fruition. Rünge's pursuit of the project picked back up, however, following the work the company did with Swindon Powertrain in the U.K. on their 911-4 engine.AdvertisementAdvertisementThe concept of a hot-rodded four-cylinder 911 engine isn't new, but the brand's 16-valve, four-cam heads are the real secret sauce. That engine became the test bed for the new flat-8 engine, which is internally known as "Hetzer." It's a 5.3-liter beast with four cams, 32 valves, and a 9000 -pm redline (that precedes a 10,000-rpm electronic limiter for the ultra brave). It should be good for around 600 horsepower. You're not getting that from an original air-cooled flat-6.Rünge CarsAs part of their collaboration agreement, Rünge Cars won't be the only ones with rights to this engine. In order for it to have a more broad appeal, it was going to have to fit into vintage Porsches without serious modifications. This is where Fin Rünge, and another collaborator named Jeff Langendoerfer, come into the picture. The latter is responsible for the hand-crafted badges that adorn Rünge products, but he also introduced the younger Rünge to CAD. The two would work in tandem with the team's U.K. contributors to 3D-scan and model both the engine bays of classic Porsches and the prototype engine itself."I've held out for a long time," said Rünge. "I'm old school in regard to things like dirty hands, tired muscles, and in my mind — sitting at a computer isn't hard work. It wasn't hard work, until I realized with Jeff coming in and doing our badges and seeing Jeff combine — he's doing Cloisonné glass fired enamel badges, but he's also semi-retired, he's learning CAD. I'm like, holy cow, this is so cool. And then Jeff would print me little parts. So him coming in, that really bridged the gap."Rünge CarsWith help from those scans, Rünge and Swindon were able to get the Hetzer engine packaged within 2 mm of the M64 flat-six engine. For those outside of the know, the M64 is the 3.6-liter engine that first debuted alongside the 964 generation of 911. It's a common swap across generations of air-cooled cars owing to its blend of power, reliability, and modern controls. The fact that the Hetzer is sized similarly is absolutely no accident; the Rünge team even printed a full-scale buck of the 911's engine bay to ensure the fit. As such, you'll be able to install one in most air-cooled cars without cutting into the firewall or other structural components.AdvertisementAdvertisement"The full-scale 3D print that took over ninety days, almost nonstop on a little home-grade, not professional grade, 3D-printer — that was incredible to see that come to life," the older Rünge told R&T. "I think it's 47 pounds of plastic."Rünge CarsFin's growing knowledge in CAD has had other uses for his father. The younger Rünge has helped shift that mental narrative surrounding computers and hard work, while also speeding along the overall build process. Headlight shapes that may have previously taken up to three days to perfect are now done in less than an afternoon. A library of reference scans help with repeatability and overall quality control. It's a massive shift in how the company operates."The more he steps in, the burden lightens," said Rünge. "When people come through the door, even guys that have been in this industry for decades, and they see what we're doing — right now I'm surrounded by leather and sewing machines and foam. We have a plating system downstairs. We have, obviously, the wheels to—or the tools to shape with the English wheel. We've got fabrication, we've got rapid prototyping, we're designing our own wheels, we're designing and building our own engines. It's weird to stop and think; [even] Pagani doesn't make their own engines. I'm like, what have I got myself into? We're not ... I don't really look at myself as a manufacturer, usually, but we are. We are a low volume coachbuilder, and a manufacturer."Rünge isn't pressuring his son to follow in his footsteps, noting that his creativity and skillset isn't simply related to cars. The pair do all sorts of projects, including furniture and interior design work. That said, there is a clear passion for the automobile buried deep in there; Fin's own personal BMW project is proof of that, but he's a deeply private young man, one who isn't chasing internet recognition with his talents. His dad still has a pretty strong feeling about where he might end up, however."I think overall everything he's learned here, it's going to give him such an amazing opportunity wherever he goes in the future," said Rünge. "I think he's going to stick around for a long time, though."You Might Also LikeIf You Can Only Own One Car, Make It One of TheseThese Are the Most Popular Cars by State