ANDIAL 3.5L Twin-Plug · Bridgehampton
For Sale · Available Now
911 SC ANDIAL 3.5L Twin-Plug
A rare ANDIAL-built road car — the legends behind Porsche's American racing dynasty.
A rare ANDIAL-built road car — the legends behind Porsche's American racing dynasty.
ANDIAL built its name on the racetrack — on 935s and 962s that dominated IMSA. Only a fortunate few road cars ever wore that same engineering. This is one of them: an ANDIAL-built 3.5-liter twin-plug stroker flat-six, assembled in 1984 by Dick Elverude, final tuning verified by Dieter Inzenhofer.
It has since been the subject of a high-end, glass-out restoration — every piece of glass removed, the body taken back to bare metal, and the finish rebuilt the slow way. Panel gaps, jambs, gutters and door shuts were all addressed, not masked over. The result is a flawless, mirror-deep finish: the silver reads clean and even in every light, with crisp shut lines and a depth of paint you only get when the work is done properly and without shortcuts.
The car balances aggression with restraint — a purposeful stance, timeless lines, sunroof and A/C intact. But turn the key and the racing DNA announces itself: the flat-six snarls awake, immediate and mechanical.
It was never meant to sit under museum lights. It was built to move — and it's offered now to the next enthusiast who'll drive it as ANDIAL intended.
Start with a stock 911 SC and you have 180 honest horsepower. ANDIAL didn't modify that engine — they built a different one. The displacement jump from 3.0 to 3.5 liters comes from an ANDIAL stroker crankshaft swinging through larger custom cylinders and high-compression pistons — the same stroker recipe ANDIAL ran in the cars that won Daytona.
The heads are the tell. ANDIAL machined them for twin-plug ignition — two spark plugs per cylinder, fired by a dual-coil setup — so the flame front sweeps the chamber from both sides at once. Combustion is faster and more complete, detonation backs off, and the engine pulls harder and cleaner everywhere in the rev range. It's the single hardest, most expensive thing to do right to an air-cooled head, and it's why "twin-plug" is shorthand for a serious build. Pair that with Carrera-spec camshafts, ported chambers, and mechanical fuel injection fed by a genuine NOS RSR racing pump, and you get throttle response no modern fly-by-wire car can imitate — every input is a cable, a lever, and fuel. No computer between your right foot and the flat-six.
And it's not a claim — it's on paper. A period Dynojet chassis dyno pull, run by ANDIAL, recorded 247.9 hp and 244.9 ft-lbs — measured at the wheels. For perspective, a stock SC makes 180 at the crank. The curves are the real story: torque is already past 235 ft-lbs at 3,600 rpm and stays above 240 across the heart of the range, so it pulls like a turbo car without the wait — just linear, immediate, naturally aspirated thrust.
"So potent, Inzenhofer joked he'd fit Goodyear air brakes."
This 911 SC was signed in the engine bay by Alwin Springer and Dieter Inzenhofer — the "AL" and "DI" of ANDIAL itself. Their signatures aren't decoration; they're authentication from the hands behind ANDIAL's IMSA dynasty.
At Luft, October 2025 — flanked by ANDIAL co-founders Alwin Springer (right) and Dieter Inzenhofer (left).
In 1975, three former Porsche racing engineers — Arnold Wagner, Dieter Inzenhofer, and Alwin Springer — met under the legendary Vasek Polak operation and struck out on their own in Santa Ana, California. They combined their initials into a single name that would come to define Porsche performance in America: AN·DI·AL.
They didn't build replicas of factory parts. They out-engineered the factory. ANDIAL became Porsche's unofficial American skunkworks — the shop Stuttgart itself turned to.
Through the 1980s, ANDIAL-built engines didn't just compete — they dominated. The 935-L "Moby Dick" conquered the 1983 Daytona 24 Hours. ANDIAL powerplants then won Daytona five straight years (1983–1987) and again in 1989.
At the 1987 24 Hours, the first five finishers were all ANDIAL-powered — an act of total engineering dominance rarely seen in endurance racing.
ANDIAL built engines for the racetrack. Only a fortunate few ever made it into road cars — and fewer still survive with their provenance intact. This 911 SC carries a genuine ANDIAL 3.5-liter twin-plug stroker flat-six, assembled in 1984 by Dick Elverude under Dieter Inzenhofer's eye, and signed decades later by the very men who built ANDIAL's racing dynasty.
It is not a tribute or a recreation. It is the real thing — racing craftsmanship from the people who dominated Daytona, made street-legal.
Fittingly, these images were captured where American sports-car racing came of age — the former Bridgehampton Race Circuit. Designed by Grumman engineers across 500+ acres above Peconic Bay, it opened in 1957 and hosted the World Sportscar Championship, Can-Am, and NASCAR. Stirling Moss called its opening turns the most challenging in North America.
The land is the exclusive club known as The Bridge now — but the legendary Chevron Bridge survives, its livery intact. That's the bridge in these frames. There is no more fitting backdrop for a car bred from racing than the ground where the sport's legends once ran flat-out.
Offered by its owner with full restoration documentation and Inzenhofer's provenance letter. Serious inquiries welcome — happy to share service records, additional photos, or arrange a viewing.