Bringing The Near-Mythical W-43 32-Valve Oldsmobile V-8 To Running Condition

There’s never enough time when you’re playing catch-up and that was the unfortunate position Ford and GM found themselves in after Chrysler dropped the block-busting 426 Hemi on them at the 1964 Daytona 500. 

It’s impossible to understate the significance of Richard Petty’s dominating win at the race. In fact, four of the top-five finishers were Hemi-powered and the shockwaves from the Hemi’s runaway performance would reverberate for years. Ford countered with overhead cams and tunnel ports at first and, later, the semi-hemi Boss 429, while General Motors’ divisions, which maintained separate and independent engineering departments, launched their own experimental engine programs. 

Chevy flirted with overhead-cam designs that never moved beyond the engine lab, while Pontiac was already deep into Ram Air cylinder head development—including taking quite a bit of inspiration from Ford’s tunnel-port design for the short-lived Ram Air V program. Over at Oldsmobile, the engineering team, reportedly including Lloyd Gill, Frank Ball, John Beltz, and others, flirted with a competing hemi design, a 32-valve V8 design and a four-valve arrangement on heads with an otherwise conventional combustion chamber. 

The four-valve heads were mounted on a 455-cubic-inch foundation and the combination was dubbed the W-43. It showed significant promise in testing, but never went into production—and contrary to legend, the W-43 heads did not have hemispherical combustion chambers nor even the semi-hemi design of the Boss 429. They were conventional pent-roof chambers, but with four valves per cylinder. 

With the relative success of conventional, two-valve arrangements on wedge-style heads, it’s logical to ask what the more expensive four-valve arrangement brought to the table. In a word: Airflow. Compared to the 2.000-inch intake and 1.625-inch exhaust valves in a conventional Olds 455, the W-43 used a pair of 1.75-inch intake and 1.375-inch exhaust valves, enabling the engine to process significantly more air. The pair of intake valves, for example, provided nearly 50 percent more intake valve area than the standard 455 head. In a May 1971 story in Hot Rod, a conservatively tuned W-43 was reportedly good for around 440 horsepower at only 4,600 rpm. More than 500 horses were thought to be within easy reach. 

Everything about the valvetrain was unique, of course, with each lifter, pushrod, and rocker arm actuating a pair of valves, and even the camshaft was raised in the block to optimize the pushrod geometry for the narrower valve angles. Additionally, the heads used centrally located spark plugs, which gave the engine the look of a Hemi and undoubtedly contributed to the myth of the W-43 being one.

A comparatively long 4.25-inch stroke helped keep a lid on engine speed, which was essential to valvetrain stability — and even then, it wasn’t great. In fact, issues with the valvetrain, including the shaft-mounted rockers, prolonged development. The W-43 had production intentions, but again, timing was everything and Olds ran out of it. 

The engine’s lengthy development peaked right around the end of 1969 and into early 1970, as all automakers were gearing up for the coming emissions-regulations changes and the ramp-up to unleaded fuel. The era of the high-compression, high-performance V-8 was ending and there wasn’t a business case to be made for the too-late and more-expensive 32-valve 455. 

Resurrected

As the legend goes, at least two W-43 engines were produced, with one sent to Petersen Publishing, in Los Angeles, at the close of the development program. It was a partial engine that had been used for valvetrain stability tests and it was photographed for stories in Car Craft and Hot Rod. Reportedly, Olds wasn’t interested in paying to have the “dead” engine shipped back to Michigan. It was supposed to be thrown away, but the parts never quite made it to the Dumpster, and they remained hidden for years. 

In 2011, those parts showed up on Racingjunk.com and were purchased by Inline Tube co-founder and Olds performance junkie James Kryta. The engine was not complete. One of the heads was missing, along with most of the valvetrain, the intake manifold, one of the exhaust manifolds, and more. 

Kryta tucked away what he had for the next decade or so, before meeting Ed Koerner, the former executive vice president of GM’s North America engineering operations, who got his start in the Olds engine lab in 1968. He was there for the tail end of the W-43’s development and was instrumental in helping Kryta resurrect the incomplete engine. 

“It wouldn’t have happened without Ed’s input,” says Kryta. “I didn’t even know where to start with some of the missing pieces and he helped steer the project in the right direction.” 

Ultimately, a new cylinder head, intake manifold, exhaust manifold, and valve covers were cast, along with replacements of other key components. The engine is largely based on the standard Olds 455, but as mentioned earlier, the W-43’s unique block features a raised camshaft position. The oil pan, water pump, and other parts are carryover items, which were essential if Olds was going to put the engine into production. 

When it came to the engine’s resurrection rebuild, a number of internal updates were made to address known design issues from the original configuration. That included redesigning the rocker arms’ shaft-mounting system, which was revamped with the help from Jesel to include an all-new girdle and other changes to help improve valvetrain stability and increase the rigidity of the arms themselves. 

The rotating assembly was also updated with higher-compression forged pistons, lighter connecting rods, and a stronger, lighter crankshaft. More significantly, the camshaft was completely redesigned. It was changed from a hydraulic flat-tappet-type to a mechanical roller, while the duration was shortened and the lobe separation angle was increased. 

“There was too much overlap and too much duration in the original camshaft,” says restorer Scott Tiemann, who oversaw the engine’s assembly. “We called in Charlie Westcott at Militia Racing Products, and he nailed the new grind perfectly. The engine idles well and sounds a lot like a W-30, while also making good vacuum for the brakes—and with the other updates, it really revs willingly, too.” 

After it was assembled, the resurrected W-43 was tuned and tested on a dyno, where it immediately made numbers that were comparable to those in the Hot Rod story from more than 50 years earlier. 

“The engine fired right up on the first try,” says Kryta. “We weren’t trying to squeeze every last horsepower out of it, as the point was simply to make the W-43 live again, but it was clear there was much more capability in the engine. It had a lot of potential.” 

Shortly after testing, the restored W-43 was slipped into the chassis of an original 1970 4-4-2 W-30 Kryta was having restored at Tiemann’s Michigan-based resto shop, Supercar Specialties. Its original engine was long gone, so dropping in the experimental engine ruffled no numbers-matching feathers. It was the fulfillment of a years-long process to resurrect the rare piece of Oldsmobile performance history. 

“The project had really taken a life of its own,” says Kryta. “Many people donated their time and expertise to help make it happen and it was very gratifying to see it all come together.” 

Although the W-43 never saw production, thanks to the looming end of the muscle car era, it nevertheless proved influential, as its four-valve arrangement reportedly was the inspiration for Olds’ landmark Quad 4 engine, which debuted in 1987. It was an idea with promise that simply ran out of time. 

Fortunately, James Kryta gave all the time required to resurrect the W-43 and we’re thrilled to share its one-of-a-kind restoration. 

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