Thursday Trivia

Welcome to Thursday Trivia where we offer up a historical automotive trivia question and you try and solve it before seeing the answer after the jump. It’s like a history test, with cars! This week’s question: What was the first post-war OHC automotive engine to be designed and mass-produced in the U.S.? If you think you know the answer, over-head-over the jump and see if you’re right. Today the OHC – or Over Head Cam engine is a pretty ubiquitous design for automobiles and many trucks, with only General Motors having being the notable holdout and most recent maintainer of the flame for mass-market pushrod engines. Pretty much everyone else has gone to the head of the cams. Production OHC engines, either SOHC or twice as much fun DOHC, were for decades the exception, rather than the rule. That doesn’t mean that a number of manufacturers didn’t see the efficiencies of the design over the frictional losses of cam-in-block, or the poor flow characteristics of flat heads. At the time, it was just dang hard to design a cost effective and reliable engine that moved its major rotating parts so far apart. One company eventually did it, and that was Crosley which adapted their Navy generator engine – a layered steel affair known as the CoBra – for automotive use. They built a bunch of those, over 45,000, but that’s not the answer to this week’s question. That engine was actually designed during the war, and what we want was the first mass-produced OHC engine designed and built in the U.S. after the war. The company that fulfills that criteria may surprise you. Then again, maybe it wont. From PickupTrucks.com

Jeep’s overhead-cam six, famously called the Tornado, was one of the first mass-produced overhead-cam engines built in the United States after World War II. As whiz-bang as that sounds, the engine actually has very humble roots. Willys Motor engineer A.C. Sampietro worked out a simple plan: In 1960 he took the existing lower-end architecture from the Kaiser Supersonic/Continental Red Seal 226-cubic-inch L-head (or flathead) six and began designing a new overhead-cam engine around it. Sampietro’s engine came to life in February 1961, when the prototypes were tested. By May, the engine had passed its 100-hour full-power certification tests, and the first production engines came off the line in April 1962. The 230-cubic-inch engine was dubbed Tornado, and in a strange twist of fate, the first Jeeps to have them were not the new Gladiator J-Series pickups or Wagoneer SUVs but the old Willys wagons and pickups they were designed to replace.

The later Pontiac SOHC straight six offered an esoteric engine option under the hoods of Firebirds and some Tempests, but that engine proved a minor dalliance from a company that seemed in the sixties to throw a lot against the wall to see what would stick. Kaiser’s Tornado suffered from design and maintenance issues – mostly around oil consumption – and was dropped from Jeep’s U.S. offerings in 1965. That wasn’t the end for this innovative motor as the tooling was sent to Industries Kaiser Argentina where it served for years in the Torino (psst, it’s really a Rambler) until its eventual demise in 1982. Image: Pickup Trucks