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One of the vital notable individuals within the 2024 Detroit Autorama is a particular Oldsmobile 4-4-2 construct packing a uncommon, experimental V-8 engine. To learn concerning the twin brothers from Detroit chargeable for this “Killer” challenge, click on right here. What follows is a technical and historic overview of the so-called W-43 prototype.
The legendary Dr. Olds was GM’s self-appointed innovation guru, with mass manufacturing, speedometers, front-wheel drive, turbocharging, a diesel V-8, automated transmissions, anti-lock brakes, and chrome plating to his credit score. So it must be no shock that Olds engineers had been pioneers within the motion to cram further valves into their combustion chambers in pursuit of additional energy. Behold, the W-43 prototype engine.
Oldsmobile’s particular efficiency packages had been usually coded with the letter W. Within the late Sixties, the trigger was volumetric effectivity: pumping further gasoline and air into—and exhaust out of—the engine to spice up torque and horsepower. Work on the prototype W-43 V-8 proven right here—a 455-cubic-inch muscle motor topped with heads sporting 4 valves per cylinder—started in earnest within the fall of 1967, although a few of its know-how had been within the engine lab for years.
One-upmanship was clearly at play within the W-43’s genesis. Within the mid-Sixties, Chrysler’s second-gen Hemi was the scourge of road and oval-track competitors. Olds strived to trump Mopar by venturing past the Hemi V-8’s two valves per cylinder.
For the four-valve W-43 experiment, of which a minimum of two examples are stated to stay, a single chain-driven cam between the cylinder banks prompts 16 pushrods. Every rod opens one pair of valves by way of rocker arms. To optimize this geometry, and to trim the mass of the pushrods in pursuit of super-high-rpm functionality, the camshaft is elevated within the block precisely one inch compared with the 455 donor V-8.
As a substitute of Chrysler’s spherical combustion chambers, Oldsmobile used a less complicated pent-roof association which tipped valve faces towards the bore’s centerline. Spark plugs are centered to reduce flame journey, a configuration that necessitated sealing tubes within the valve covers. Pistons are domed.
To expedite the event of those new cylinder heads, Olds engineers employed a circulate bench that might precisely assess momentary mahogany fashions. Finest outcomes had been achieved with 1.75-inch intakes and 1.375-inch exhausts. This yielded a 43 p.c improve in valve curtain space—probably the explanation that determine was chosen for this engine’s code title (curtain space = valve circumference x raise).
The 455-cubic-inch block, which continued 4.125-inch bore and 4.25-inch stroke dimensions, included one notable improve: To guarantee sturdiness, new four-bolt principal bearing caps had been machined from cast metal.
Check outcomes reported by Scorching Rod journal indicated a peak output of 440 horsepower at 4600 rpm with delicate valve timing and a 4×2-barrel induction system. These figures are modest by right now’s requirements probably as a result of the engine was measured early within the improvement course of.
The late Sixties had been Motown’s horsepower heyday. The Hurst/Olds specials launched in 1968 at the moment are extremely prized collectibles. Olds engineers additionally constructed sizzling marine powerplants and twin-turbo V-8s supposed for Can-Am racing. A derivative design was coded OW-43. Experimental dual-overhead-cam, 32-valve V-8s had been additionally constructed for dyno testing.
Sadly, doomsday lurked across the bend. Within the early Nineteen Seventies, the feds tightened emissions requirements and OPEC triggered an vitality disaster with an oil embargo. Precisely what Olds didn’t want was a V-8 which was heavier, bulkier, costlier to fabricate, and thirstier than standard designs.
Thus, the W-43 was shelved and by no means reached manufacturing standing.
It wasn’t all wasted effort, nevertheless, as this incredible footnote demonstrates: Oldsmobile’s 2.3-liter Quad-4—produced from 1987 by way of 2002 and used to energy hundreds of thousands of Chevys, Oldsmobiles, Pontiacs, and Buicks—furthered W-43 classes from the ’60s with the addition of twin overhead cams. The Quad-4 was America’s first four-valve engine in addition to the ultimate powerplant wholly developed and manufactured by Oldsmobile.
That legacy additionally contains an entry within the velocity data books. An Olds Aerotech streamliner, powered by a turbocharged Quad 4 and pushed by A.J. Foyt, topped 267 mph in an epic 1987 measured-mile run on the Fort Stockton Check Heart in Texas, seizing the world land-speed report from Mercedes-Benz.
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