The Mopar 340 has its origins with the previous 318 V8 engine in the LA family. This was already a pretty good engine, but Mopar wanted to make a high performance version of it. To do this, the company took the 3.906 bore of the 318 and increased it to 4.04 inches, but the designers did not alter the stroke at all, allowing for a greater engine displacement. Mopar also understood that there would be a heavier burden placed on the engine due to its performance capabilities, so it replaced the cast iron crankshaft with a steel one.
The result was a rather impressive engine that could generate up to 275 horsepower and 340 pound-feet of torque — or at least that is what was advertised, as Hot Rod saw those numbers improve to 320 horsepower and 368 pound-feet of torque. These results made the engine quite a nice choice for street racers or anyone wanting a lightweight, powerful vehicle.
You would find the 340 V8 in several of the muscle and pony cars after its introduction in 1968, including the Dodge Charger and Plymouth Road Runner; and two years later, Mopar would put out a Six Pack version of the 340, which was exclusive to the Dodge Challenger and Plymouth Barracuda. As was the case with so many high performance V8 engines of the time, it became significantly hampered by the emissions regulations and oil embargo during the 1970s, seeing it phase out of production rather quickly. However, this has made it quite the product on the resale market that you will certainly be paying several thousand dollars to get.
[Featured image by Bidgee via Wikimedia Commons | Cropped and scaled | CC BY-SA 2.5 AU]
