You probably know the story of the 917/30. You probably saw it run in all its Can-Am Cup-quashing glory back in 1973, with its engineer Mark Donohue at the wheel. You may think motorsports had never been so good nor produced a car so dominant. And youd be right.

A Porsche historical document described the advent of the 1973 engine:

Back then, the 917s dominance was so stifling that motorsport authorities decided to intervene. Porsche had won the manufacturers title at the World Sportscar Championship in 1970 and 1971. The 917 had racked up 15 endurance victories, including the brands first two overall victories at the 24 Hours of Le Mans, before its 5.0-liter, 12-cylinder engine was no longer permitted to compete in 1972.

It couldnt compete in Europe, but here in North America there was this thing called the Can-Am.

Canepa

Porsche found a new field of activity. North America had long since become the brands largest individual market, and the Canadian-American Challenge Cup, or Can-Am for short, became an attractive racing series. In order to be able to compete against the dominant McLarens and their 800-hp V8 engines from Chevrolet, the V12 (normal-)aspiration engine of the 917 was not enough. Performance improvement by turbocharging was still largely uncharted territoryone that Porsche explored.

Among the explorers was American Mark Donohue, a successful race-car driver and engineer. Thirty-four years old at the time, he was appointed developmental and factory driver. In 1972 the approximately 1,000-hp 917/10 TC Spyder (TC stands for turbocharged; Spyder refers to the now-open cockpit) won six Can-Am races and the title. As competitors got their vehicles ready for the 1973 motorsport season, Porsche presented its answer: the 917/30.

And we all know what happened after that, a dominant season so thorough, that it eventually killed the whole series. By 1975 Porsche used the car, with Donohue at the wheel, to set a closed-course speed record at Talladega that would stand for 11 years.

A 917/30 sold for $4.4 million in 2012

After that, Roger Penske owned the car for a while, sold it to LA collector Otis Chandler, who sold it to French collector Jackie Setton. Motorsports restoration mega-specialist Bruce Canepa found the car and sold it to its current owner, Rob Kauffman, who had Canepa restore the whole thing, including rebuilding both the 5.4-liter engine you see here and a spare 5.0 flat 12, both things of beauty to certain eyes.

But unless you worked on the team back in the day, chances are youve never seen a 917/30 engine out of the car. Well, feast yer eyeballs upon its magnificence presented here.

Canepas shop in Scotts Valley, California, just finished rebuilding the 5.4-liter flat-12 turbo engine from Donohues car, with help from original engineers Valentin Schaeffer and Gustav Nietzsche.

To have Gustav teaching us and Valentin teaching, it's been unbelievable. You know, retired factory guys helping out. And then Ed Pink Senior, all three of them helping, said Canepa.

Canepa

Before stuffing it back into the blue and gold Sunoco chassis, the Canepa people took some photos of it, which is what you see here. Look at it and ponder the engineering that went into it, back in the days before CAD, CFD, CAE and a bunch of other C acronyms. Back when all the German engineers and Donahue had were their enormous brains, some pencils and a slide rule. Canepa is still in awe of it all.

What's amazing is when you go back, now you're talking about the early 70s, when you look at the brainpower of those guys between (Hans) Mezger and Valentin Schaeffer and the guys building the engine, when you look at the brainpower, they didn't have computers telling them, there wasn't a program on how to build an engine. I mean, this is all in their heads. And to build that big an engineand it's a big engine, its size, it's a big thingto build that thing and have it run 8,000 rpm, which is a lot for a big engine, and make that kind of power boosted and reliable. I mean, that engine would run for 25, 30 hours without them touching it. Those guys were geniuses, period.

So it must have been kind of cool to be able to take one all apart and put it back together again. Canepa figures theyve done seven or eight rebuilds on 917 engines in the last three years, both the normally aspirated flat-12s that won the World Sportscar Championship and Le Mans in 1970 and 71, and the later turbo powerplants like this one.

Those engines were incredible. And when you see them all apart and you look at the pieces, and you just study the design of it, even if you don't even know what you're looking at, you're just impressed. Just in all the detail and all the things they were paying attention to.

If you ever get a chance to go to the Rennsport Reunion or anywhere one of these great race cars are shown, try and lean over to get a peek into the engine bay. You wont be disappointed.

This content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. You may be able to find more information about this and similar content at piano.io

This commenting section is created and maintained by a third party, and imported onto this page. You may be able to find more information on their web site.

See the article here:
Gaze in Wonder at This Porsche 917/30 Flat-12 Fresh out of Canepas Shop - Autoweek