The ’70s Oil Crisis Was So Bad Dealerships Put Boat Diesel Engines In Dodge Darts

The infamous Oil Embargo Of 1973 and concerns about the environment triggered a pivot in the automotive industry. In short order, large and thirsty vehicles fell out of style while the government began reining in automakers on emissions. Diesel engines, once largely reserved for large trucks and heavy equipment, became a beacon for those wanting to save the most money possible. America placed diesels in a lot of unexpected places and one of them was the Dodge Dart. Yet, while you could have bought a new Dart with a diesel, it didn’t come from Dodge that way.

It’s fascinating how many automotive stories can trace their roots back to those events of the early 1970s. Astronomical fuel prices and fuel shortages sent Americans scrambling for smaller, more efficient vehicles. Engine horsepower ratings switched from gross to net, erasing the glorious power numbers from the turn of the decade. Then, emissions regulations further delivered a gut punch, ensuring you could buy cars with sizable 350 cubic inch V8s that made all of 125 HP on a good day. Of course, safety was also a huge concern for the day and vehicles found themselves adorned with the automotive equivalent of old dental braces.

There was also a flood of interesting ways to beat high fuel prices from the rise of cheap three-wheel vehicles to an abundance of cheap, but crappy electric vehicles. It seemed like saving money was on everyone’s mind from the executives of Detroit’s automakers to the handyman in his shed.

The Dart existed as one of those smaller choices for Americans eschewing full-size rides for something a bit more thrifty. But there was a way for Dart buyers to save even more cash than just by going smaller.

A Perfectly Cromulent Compact

As Hot Rod Magazine writes, 1959 was a hotly competitive year for the domestic automakers. Interest in low-priced cars was rising and robbing sales from the mid-priced market. Dodge’s solution to the popularity of low-priced models was the introduction of its own low-priced car, the Dart. The 1960 Dart was a full-size, but cheaper model designed to take Chevrolet’s, Ford’s, and even Plymouth’s lunch money. The new Dart didn’t do anything revolutionary but had enough changes from the 1960 Dodge to make it identifiable, including a 118-inch wheelbase.

Reportedly, the full-size Dart wouldn’t last long as Dodge realized the strength of the compact market. It responded in 1962 by shrinking the Dart onto the firm’s intermediate body platform. Over the years, the Dart continued to ride on a compact platform and receive updated styling as well as larger top engines. You were even able to get your Dart with a chunky 440 cubic inch V8!

The Dart we’re talking about today hails from the early 1970s to about the mid-1970s. In 1970, the Dart was given a comprehensive facelift which made it look like a scaled-down full-size Dodge. Later converted Darts were victims of the early days of the Malaise Era, which meant they were adorned with the era’s infamous impact-absorbing bumpers. As Curbside Classic notes, the Dart had also been riding on the same basic platform it had since 1967. It wasn’t all bad, however, as Dodge gave the Dart Chrysler’s electronic ignition, and models equipped with disc brakes got single-piston calipers that were easier to work on. The Dart also got an improved HVAC system plus optional cruise control.

The Dart wasn’t flashy, nor was it a status symbol, but Americans seemingly didn’t care. Dodge sold 78,216 Dart and Dart Custom models in 1974, handily beating other vehicles in Dodge’s lineup that year. Sadly, Dodge never released sales data for the Dart SE that was introduced that year, but there was even a chance that the Dart could have beaten its Chevy Nova competition.

In 1974, you could order your Dart in a variety of trim levels ranging from the Dart Custom four-door sedan to the Dart “Convertriple” coupe. Something interesting in the brochure was the fact that a Dart could tow up to 2,000 pounds thanks to a factory-installed trailer package consisting of a hitch, heavy-duty suspension, wider wheels, and a trailer wiring harness.

The hottest Dart in 1974 was the Dart 360 Sport, which sported a 245 HP 360 cubic inch V8 with a four-barrel carburetor, dual exhaust, a sportier suspension package, and power front disc brakes. If you wanted to save some dough, your engine choice was likely the 198 cubic inch slant-six, which made 95 HP.

While Dodge advertised economy as a selling point for the Dart, I did not find a claimed MPG figure in the documentation. Individual owners reporting in seem to suggest that mpg in the mid-20s should be achievable with the slant six. But, what if that still wasn’t enough for you?

Saving Money At The Pump

A number of companies and individuals converted Darts through the 1970s, but we have been able to find a decent bit of information about one particular conversion that is still talked about on forums today.

As the August 1974 issue of Motor Trend reports, there was once a time when Americans thought the diesel engine was the future of clean, inexpensive energy. Maybe one day we’d all be driving cheap diesel cars and living in impossibly tall skyscrapers. Of course, the reality was that Detroit’s automakers weren’t fully invested in diesel passenger cars just yet.

That didn’t stop Tony Carpanna of the Wilcap Company of California. Wilcap was a supplier of flywheels, transmission adaptors, engine mounting hardware, and more for hot rodders and classic car owners. It’s a company that’s still around today, though Carpanna has passed. Carpanna saw a future in diesel even before the Oil Crisis. Diesels of the era were noisy, heavy, subjected drivers to heavy vibrations, and lacked power compared to their gasoline counterparts. However, diesels were also known for longevity and fuel economy. Carpanna started custom diesel car conversions in 1969.

In 1974, Motor Trend noted that Carpanna put diesel engines in all sorts of vehicles from the Ford Pinto to the Dodge Dart. To achieve this, he went over to Nissan Diesel, a Japanese company that was once known as Minsei Diesel before Nissan acquired it in 1960. Nissan Diesel was not directly Nissan-Datsun, but a subsidiary.

Compacts like the Pinto got a Chrysler-Nissan four-cylinder diesel good for 64 HP. Thankfully, the Dart got the bigger option.

The engine Carpanna used for Darts was the Chrysler-Nissan CN6-33, a diesel straight-six made by Nissan Diesel for Chrysler. What was one of the primary uses of the CN6-33? Boats! Also stationary industrial equipment, but it’s far more amusing to think of tossing boat engines into cars. A relative of this engine, the SD33, was used in the International Scout.

Carpanna’s conversions, which Dodge dealers handled, offered Dart buyers and owners a choice of two versions of the CN6-33. The base model was a 198 cubic inch naturally-aspirated straight-six diesel making an unspecified amount of power. If you opted for the optional turbocharger, your output increased to 92 HP and 137.5 lb-ft of torque. The second of the two options sounds close to a modern Volkswagen TDI, but Motor Trend would say not so fast.

The conversion included the engine, the labor to install the engine, the optional turbo, and a conversion kit for the air-conditioner. The rest of the Dart, including the rear gearing, was as you bought it as a gas-powered car. Motor Trend said the turbodiesel Dart was a “slug” when accelerating and if you owned a Dart with tall gearing, you had to slip the clutch for a very long time just to get the darn thing rolling. Worse, if you chose a new Dart with an automatic transmission and 2.37 gearing, the magazine doubted the car would even move under its own power.

But, once you did get moving, Motor Trend said the diesel-converted Dart got 31.7 mpg with the air-conditioner on and an impressive 34.9 mpg with the air-conditioner off. While Motor Trend said that the car’s noise levels were acceptable at expressway speeds, there wasn’t much passing power in reserve. So, I hope you were happy staying in the slow lane.

Despite the downsides, Motor Trend concluded that the diesel Dart was a fine way to combat inflation. It was outrageously thrifty and in the magazine’s opinion, the quality of Carpanna’s work was probably better than what Detroit could have done on its own back then. The icing on the cake was that diesel was cheaper than gasoline at the time, too.

For another example of a converted Dodge from the Malaise Era, check out the diesel-powered Aspen in the photos above. It also houses a Chrysler-Nissan straight-six!

Twice The Price For One Car

Unfortunately, repowering a Dart wasn’t cheap. A Dodge Dart Sport was $2,842 ($19,229 today) in 1974. The purchase of the Nissan diesel engine plus the labor to install it was $3,000 ($20,298 today) all on its own. Then you had to pay another $500 ($3,383 today) for the turbo if you wanted to have any chance at keeping up with traffic. Restoring the function of your air-conditioner was another $250 ($1,691 today) fee. If you went the full ride, that was a $6,592 expense ($44,602 today) to save money at the pump. Even if you already owned a Dart you had to spend more than the value of a new Dart to save gas money.

It’s not known how many Darts were converted to diesel through Wilcap, but they’re so rare that they barely even exist. Wilcap wasn’t even the only company doing conversions, either. Other firms that did diesel conversions in the era included Economy Systems and American Automotive Engineering, which also converted everything from pickup trucks to vans with SD33 engines.

The car I’m showing you today is a 1971 Dart that was converted by a dealership. It was listed for sale on Facebook last year for $12,000. The documentation provided with the vehicle suggests it may have been an early Carpanna conversion, but this hasn’t been confirmed. Sadly, it sold long ago, but the ad is still up if you want to look at some seriously cool photos.

A person who claimed to be the former owner of American Automotive Engineering said that part of the reason why the conversions were so expensive was due to Chrysler. The conversion companies could have imported diesels from Canada for cheap, but allegedly, the only way Chrysler was okay with the diesel conversions was if the conversion companies sourced the engines from Chrysler Marine in the United States for roughly $2,400 ($16,238 today) per crated engine.

How rare are these conversions today? The pictures you see here are from the only listing I could find archived anywhere. Of course, even if there were a lot of these vehicles converted, the march of time is unbeatable. Who knows how many have been lost to corrosion or just typical use.

Given the power of hindsight, we know the dreams of a diesel future have been foiled numerous times from GM’s infamous failure with the Oldsmobile Diesel and Volkswagen’s failure with its TDI “Clean Diesel.” Still, it’s awesome to see that at least some people tried. Diesel power was, at least, seemingly the right fuel at the right time. So, if you happen to find a 1970s Dodge Dart with a diesel engine in it, the car was likely one of these weird diesel conversions. I’d love to drive one of these one day.

(Correction: The original version of this story called a Dodge Aspen an early Dodge Dart. I regret the error and have corrected it.)
(Images: Facebook Seller, unless otherwise noted.)