No, it's not related to the Chevrolet 4.3-liter V6.
Nearly five years have passed since our last episode of the Cut-Down Engine of the Week series, in which we admired International Harvester’s one-bank-of-a-V8 Comanche four-cylinder. The half-a-V8 method has saved many an engineering and production dollar for vehicle manufacturers, as has the two-thirds-of-a-straight-six design, but perhaps the most popular means of lopping cylinders off a proven mill has been the V8-based V6.
By far the most successful such engine has been GM’s Buick V6, which started life as three-quarters of the early-1960s Buick V8 we now know best as a Rover product. One of the least successful such engines was Oldsmobile’s 4.3-liter diesel V6, available in various GM cars for the 1982 through 1985 model years.
As is the case with so many of these tales, I was reminded of the seldom-seen Olds 4.3 diesel during a trip to the junkyard. I spotted this 1983 Cutlass Ciera diesel in a Denver car graveyard, located just a few rows away from the equally rare 1984 Toyota Corolla diesel.
Everyone knows about the Chevrolet 4.3-liter gasoline V6, which was three-quarters of the good ol’ 350 small-block V8, but the Oldsmobile 4.3 V6 is completely unrelated to that cut-down engine. The Olds 4.3 was made in the same way, by lopping a couple of cylinders off a 350-cubic-inch (5.7-liter) V8 and designing a new even-fire crankshaft for the resulting V6, but that V8 was the dreaded Oldsmobile 350 diesel that caused GM so many headaches and contributed greatly to turning Americans off oil-burning engines for decades after.
Car shoppers could get the 4.3 diesel in everything from a Chevrolet Celebrity to a Cadillac Fleetwood. It was rated at a miserable 85 horsepower and a pretty decent 165 lb-ft of torque.
Diesel power allowed GM to claim some amazing (for the time) fuel-economy figures in their cars, which was a big selling point in the immediate aftermath of the gas-line-hell 1979 Oil Crisis caused by the Iranian Revolution. In 1981, a new diesel-powered Chevy Caprice wagon could drive at the legal speed limit for 13 hours on a single tank! Not only that, during the 1979 shortages, diesel was often available when gasoline couldn’t be found at any price. Fuel prices collapsed by the mid-1980s, reducing the appeal of diesel cars.
The Olds 4.3 diesel was based on the 5.7 after many of the V8’s highly publicized problems had been sorted out by GM, so it worked well enough. The damage to diesel’s reputation had been done, though, and few car buyers selected this engine.
Keyword: Cut-Down Engine of the Week: Oldsmobile 4.3 Diesel