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The Impossible Dream- Restoring a derelict Citroen SM at home.

Citreon SM

Robert Blackmon of Los Angeles is a heavy truck owner/operator and about as nice a man as you’ll ever meet. His automotive passions have always leaned toward foreign cars. 

He loved the Citroën SM at first sight, appreciating its design and advanced features, vowing to own one someday. That day came in 1982 when he bought a ’72 SM from the late Gerald Wiegert of Vector Aeromotive fame. 

Working on Citroen SM
Citroen in garage

The Maserati DOHC V-6 engine was damaged, and the car was a non-runner, but the price was right. In his home garage, working alone with very average hand tools and a cryptic shop manual, he took the car apart and commissioned a “cut corners” engine rebuild. That engine lived for nearly 80,000 miles but grew tired, so Blackmon decided the next disassembly would be a more proper restoration — including an exterior color change to the current silver — and a top-quality engine overhaul. Blackmon credits SM World guru Jerry Hathaway with “parts, machine work, and tons of good advice.”

Blackmon’s SM has now covered around 200,000 miles and, save for the patina of use and enjoyment, drives beautifully. 

completed Citroen

What made this self-taught home mechanic believe he could restore and maintain such a complex French-Italo hybrid full of cams, carbs, and a high-pressure hydraulic suspension and brake system? “It’s still mechanical — that’s the difference,” reflects Blackmon.

“There are no sensors or computers. It’s a highly detailed but very mechanical car, so I just figured it out. It required basic tools, good advice and patience — Lots of patience.”

Robert Blackmon
Robert Blackmon
Inside the Citroen SM

Why? It’s unlikely that we’ve answered the question of “why” people take on seemingly insurmountable cars, which is somewhat akin to asking why someone would climb Mt. Everest and risk financial ruin, frostbite, injury, or death. 

Those motivations are often very personal and sometimes emotional — but every enthusiast can look at a forlorn vehicle through the proverbial “rose-tinted glasses” and see it straight and sparkling once again, and that’s the real crux of the matter.

What immediately impresses you most about the SM driving experience is the ride quality. Supple, smooth, and ultra compliant courtesy of a sophisticated hydraulically managed suspension (and braking) system that soaks up most anything the road can throw at it – speedbumps become a mere suggestion to slow down. Highly effective, but something that takes a bit of getting used to is the brakes. The SM has no mere “brake pedal” — neither hung from the dash nor levering up from the floor. Instead, it’s a black, rubber-covered “button” for lack of a better term, about three inches in diameter, and a couple of inches tall, mounted on the floor about where you’d expect to find a conventional pedal pad. The system offers some modulation, and the well-calibrated foot can manage it. But the high-pressure hydraulics make the button pretty sensitive, and the hamfisted (or footed) driver will look to be panic-stopping all the time.  

Citroen sign

The SM’s aerodynamics are superb, with a near race car-like 0.28 coefficient of drag, so slippery in the wind, and quiet inside. The cabin design is very modern, almost concept car-like, and quite comfortable. There’s great room for four and a large glass hatch canopy aft for plenty of luggage space (and, unfortunately, solar heat loading inside). The car handles nicely too and would be a great way to tour the Continent in style and comfort.

Perhaps President John F. Kennedy unknowingly summarized this automotive “leap of faith” notion during his famous 1961 speech announcing that America would fly man to the moon, and safely home again. He said:

“We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard.”

I wonder if JFK ever worked on a Citroën hydraulics system.

The Maserati Citroen connection

Marek and SM together

And how does a relatively exotic Maserati V-6 end up in the front end of a Citroen gran touring coupe? Semi simple, really. In one of those transactions that everyone likely knew just couldn’t last, Citroen owned Maserati from 1968-1982.  

The French concern required a beefier engine for a planned high-tech, front-engined, front-wheel drive gran turismo coupe (which became the SM) as its roster of generally smaller I-4s just weren’t up to the high-performance job intended.  

Maserati engine

As opposed to developing its own new engine from scratch, which it certainly was capable of doing, Citroen decided to go motor shopping, and ultimately ended up on the doorstep of Modena, Italy’s Maserati, certainly an outfit that knew how to build an exotic engine.  

Through a long and convoluted negotiation between the two companies (and the Italian government) Citroen ended up with its new engine…and the rest of the company along with the deal.  

Amazing as it may seem, Citroen assumed ownership of Maserati; this was not a merger per se where the two brands would be comingled. 

Citroen SM badge

Instead, it was a buyout where each brand would retain its independence from a customer-facing point of view.

While the new Maser V-6 certainly shared some design aspects derived from its outstanding 4.2- and 4.9-liter V-8, it was ostensibly new, unique with its timing chain running vertically through the middle of the engine between a couple of the cylinders.  

For Citroen’s purposes, it was initially engineered at 2.7-liters, rated at 174 horsepower, backed by either a 5-speed manual FWD transaxle or a 3-speed automatic unit. You wouldn’t call the SM fast, but it was a solid enough performer, capable of moving the SM about smartly and up to a speed of over 120MPH. The first SM’s ran carbureted engines, and fuel injection came along later.

Engine of Citroen

There was nothing in the purchase transaction paperwork that prevented Maserati from using this engine in a vehicle(s) under its own brand. The mid-engined V-8 Bora was its front line supercar at the time, so ItalDesign reworked the shape and platform a bit, added +2 seating, working in a 3.0-liter version of the SM V-6, and called it Merak.  

The Merak also used the SM’s transaxle and front suspension, which became the rear suspension in the Maserati. The best performing and most developed Merak model was called the Merak SS, with horsepower ratings in the 215-220 range depending upon whose tests you read. The SM was produced from 1970-1975, and the Merak ran from 1972-1983.

Photos by the author and courtesy Robert Blackmon