Good morning! Welcome to your mid-week edition of Shitbox Showdown. Today is all about an arcane form of induction known as twin carburetors. We’ve got two prime examples for you, but first, let’s see which Kansas truck you chose:
Another day, another landslide Mopar win! You guys feeling all right? It’s just that typically… well, anyway. Normally I’d greatly prefer a GMT400 to a Dakota, but considering the condition of these two particular trucks, I think the Dakota is worth the extra $600.
Now then: If you want a gasoline engine to make more power, you need to give it more stuff to burn. These days, with electronic fuel injection, it’s easy; you just say, “Hey ECU, put more stuff to burn in the engine.” But in earlier ages, the way to give the engine more air and fuel to burn was to use bigger, or more, carburetors. Larger engines got a little crazy with this: V8s in the 1950s and 60s came equipped with crazy setups like “dual quads” (two four-barrel carbs) or “six-packs” or “tri-power” (three two-barrel carbs from Chrysler and GM, respectively). Chevy’s Corvair flat-six could be had with four single-barrel carbs. Italian V12s took the cake with six two-barrel Weber carbs, or one barrel per cylinder. And almost every little British sports car sported two side-draft carbs on its four-cylinder engine.
Nowadays, tuning a multiple-carb setup seems like some mystical black art to most people. I’ve even met “hardcore” British car people who replace the twin carbs with a single Weber downdraft carb, because it’s “easier to tune.” But I’ve found just the opposite to be true; typical single-barrel side-draft carburetors have very few moving parts, stay in tune once you get them tuned, and can be tuned by ear with a screwdriver and an open-end wrench once you know what to listen for. Besides, they just look cooler. So today, we’re celebrating the twin-side-draft carb setup with one British sports car, and one Swedish sedan sporting British carbs. Let’s see what you make of them.
1980 Triumph TR7 convertible – $3,500
Engine/drivetrain: 2.o liter overhead cam inline 4, five-speed manual, RWD
Location: Orinda, CA
Odometer reading: 97,000 miles
Runs/drives? Has been sitting for a year, ran great before that
As an MG guy, I’m supposed to hate the TR7. In the 1970s, in the midst of serious labor and financial woes, British Leyland could only muster enough funding to replace either the MGB or the Triumph TR6. “Project Bullet,” as the car was known, was supposed to be the new MG sports car, but ended up going to Triumph instead, probably because the simple MGB was cheaper to keep cranking out than the more complicated, more expensive TR6. In the end, it didn’t matter much anyway; MG closed its doors in 1980, and Triumph only lasted two years longer.
The TR7’s biggest claim to fame is the first of two Swedish/British connections we have to talk about today. This engine, developed by Triumph, was supplied to Saab for use in its 99 model starting in 1968. Strangely, it didn’t see the underside of a Triumph bonnet for another four years, until the 1972 Dolomite sedan. For the TR7, Triumph punched this engine out to two liters, and equipped it with twin Zenith-Stromberg variable-venturi carbs. It faces forward and drives the rear wheels – unlike Saab’s weird backwards front-drive arrangement – through a five-speed gearbox.
This TR7 has been parked for a year, for reasons unknown. The seller says it was running and driving fine when parked, so it doesn’t sound like a mechanical issue sidelined it. More likely life just got in the way; surplus “fun” cars are usually the first thing to get neglected when things happen. At least they’re up front about it. But a year isn’t that long for a car to sit; I’d guess that with some fresh gas, this puppy would fire right up. Assuming, of course, that they’re being honest about its pre-storage condition.
Cosmetically, it’s in nice shape. The orange paint (there aren’t enough orange cars) looks nice and shiny, the interior looks good, and it sits on nice Panasport wheels with newer tires. The back window is cloudy, but you can’t see that when the top is down.
1965 Volvo 122S “Amazon” – $4,500
Engine/drivetrain: 1.8 liter overhead valve inline 4, four-speed manual, RWD
Location: San Rafael, CA
Odometer reading: 66,000 miles (but not accurate)
Runs/drives? Just fine
This car is officially known as the Volvo 122S everywhere except its home turf. Owing to a trademark dispute with a German motorcycle company, Volvo wasn’t allowed to use the Amazon name anywhere except Sweden. And these days, I imagine that guy who runs that website might take issue with the name as well. Regardless, in classic car circles, this is, and forever will be, the Volvo Amazon.
This car’s B18 engine, a five-main-bearing pushrod design, is famous for its durability. Irv Gordon’s legendary Volvo 1800S, the car with the highest documented mileage ever, is powered by the same engine. Feeding this rock-solid motor is a pair of British-made (there’s our other connection) Skinners Union variable-venturi side-draft carburetors. These little marvels make no sense if you’re used to typical fixed-venturi carbs, but once you understand how they work, they’re kind of genius. SU and and Zenith-Stromberg carbs of various sizes could be found on everything from Austin-Healey Sprite four-cylinders to massive Jaguar V12s in addition to these Volvos.
[Editor’s Note: I used to have a Volvo 1800S with twin SUs, like this, and I loved them, but they did leak at times, and when they did they dripped right onto the hot exhaust manifold below, making some alarming smoke signals. Other than that, though, I love these weird bottle-looking carbs. – JT]
This Volvo’s mileage is an unknown quantity; the odometer reads 66,000, but the seller says that isn’t accurate. Its condition can be ascertained from the photos, though, and it’s pretty damn good. I see a few paint blemishes, and some wear on the inside, but overall, it’s a good-looking car. It’s the sort of classic you can enjoy without worry, because it’s not too nice. I’ve driven a couple 122s, and they’re no one’s idea of a sports car, but they are fun to drive in their own stately way.
I do wish we had some bigger and better photos of it. But from what I can see, and what the ad says, this sounds like a good deal on a cool old classic car.
So there they are, two classics with engines fed by a pair of black-magic carburetors. One runs perfectly, and the other is likely only some fresh gas and a tune-up away from purring like a kitten. Which one is right for you?
(Image credits: Craigslist sellers)
[Editor’s Note: I used to have a Volvo 1800S with twin SUs, like this, and I loved them, but they did leak at times, and when they did they dripped right onto the hot exhaust manifold below, making some alarming smoke signals. Other than that, though, I love these weird bottle-looking carbs. – JT]
That’s what happens when cork, rubber and paper gaskets age. Those carbs with modern silicone gaskets work just fine.