By Dean Larson

The Porsche 917 is a fairly common sight on the replica market. Thanks to a commanding performance in FIA Group 5 racing and prominent use in the 1971 film Le Mans staring Steve McQueen, the Porsche 917 is widely recognized and revered. However, this 917 is a bit different than most replicas you see for sale. For one, it’s recreation of Jo Siffert's 917/10, rather than the more recognized 917K. Secondly, this example has been painstakingly constructed by hand, including the use of two Subaru EZ30 engines joined at the crank, to make a single 12-cylinder engine.

It’s tough to really summarize the level of constructive insanity employed in the construction of this running (yeah, it does actually run) vehicle. It looks like the builder started from the ground up, building a tubular chassis that bears resemblance to the original 917 in some key areas. The front suspension sorta resembles the Corvette C4 design, which would explain the Vette wheels used in some photos, but the rear suspension is a mystery.

Jo Siffert's original 917/10 was powered by a 5.0-liter, 12-cylinder engine and made roughly 500 hp. Since a unit like this would be impractical, borderline impossible, to use in a homebuilt replica, the owner decided to construct his own V12. Unlike most Subaru Boxer engines, which are configured as flat-fours, the Subaru EZ30 engine features a flat-six layout, and saw use in mostly in the Subaru Outback and Legacy. Most variants displace roughly 2.9 liters and produce 220, to 240 hp.

While a single water-cooled, 2.9-liter flat-six engine wouldn’t be a bad option for a vintage Porsche replica, two of these Boxers joined at the crank is simply bonkers. From the images, it appears that the first engine is laid out in reverse, with its dampener joined to the second engine’s dampener. However, this wouldn’t make sense, as the rotation would have to be reversed in this configuration. Either way, the second engine then feeds all 440 hp (presumably) through an unnamed five-speed transaxle. The car does run and drive, but the builder explains that he would like an “experienced and enthusiastic” electrician to construct the finished wiring harness.

Above all else, I find it astonishing that this homebuilder was able to design this powerplant and actually make it work in an honest-looking 917 replica. As is, the seller would take $59,000 for the car, which will need final assembly, wiring and bodywork. It’s tough to comment on that figure, as this is truly a one-of-a-kind machine, but we’re definitely willing to be you couldn’t have this thing built for that price.

Check out the seller's ad here on Hartford Craigslist, and here's a couple videos showing the car running and driving.