One of the early adopters of street performance (’49 Rocket V-8 coupe), Oldsmobile kicked butt with the ’66 OLDS 4-4-2: TRI-POWER ROCKET!
When carmakers announced their 1966 models in September 1965, it was like the Musclecar/Supercar floodgates had opened. Ford had already proven that its 1964-1965 marketing mantra – “Win On Sunday, Sell On Monday” – worked. For 1966, Chrysler, Ford, and General Motors unleashed their all-time hottest models, and it was nirvana for car enthusiasts and automotive magazine editors!
One of the finalists for our Top Performance Car honors at Hi-Performance CARS magazine was the ’66 OLDS 4-4-2: TRI-POWER ROCKET! Olds’ engineers had finally come up with a big-engined midsize car to compete seriously with Pontiac’s GTO. Not long after revealing the latest 4-4-2 with four-barrel 400/350, they upped the ante with a late-arriving Tri-Carb version conservatively rated at 360 horsepower. It was Oldsmobile’s first use of three-two-barrel induction since the legendary 1957-1958 371-cube J2 Rocket V8s, rated at 300 and 312 horsepower, respectively.
We found that an L69-option Tri-Carb 4-4-2 with four-speed and 3.90 Anti-Spin gearing was quicker and faster than the 360-horsepower Tri-Power GTO we tested for March 1966 Hi-Performance Cars. GTO styling was refreshed in 1966, and it became a distinctive model series, no longer an option on the Tempest. The GTO’s best time was 100 mph in 14.50 seconds, compared with an L69 Olds’ 13.80s and approximately 105 mph.
Oldsmobile engineers worked on the L79 W-30 engine project in late 1964 and 1965, and Tri-Carb packages first surfaced on ’65 4-4-2 Mules. The Lansing Engineering facility was down the road from Demmer Tool & Die, a GM supplier. There was a lot of “information” sharing between Olds and Demmer drag racing engineers. Demmer raced a Tri-Carb 4-4-2, RECTIFIER-2, and worked closely with Oldsmobile. In 1968, Demmer built the 455-inch Hurst Olds. Unlike GTO Tri-Power with vacuum-operated linkage opening the end two Rochester 2GC carburetors, the Oldsmobile L69 Tri-Carb utilized a smoother, progressive mechanical linkage.
An Oldsmobile 4-4-2 performance brochure encouraged enthusiasts to not only buy a 4-4-2, but “Turn it on. Tinker with it. Make it dance to your tune.” “Exclusive on the 4-4-2 Tri-Carb. For peak breathing at the high end, just pull two bolts from the crossover valves on either side of the center carb, rotate the covers 90 degrees and bolt them back down.” It was not great for cold starts, but perfect for taking advantage of cooler, denser air-fuel mixture for better performance!
With a choice of Anti-Spin gearing up to 3.90 and dealer-installed 4.11 or 4.33 gears, plus close or wide-ratio Hurst-shifted four-speeds, the ’66 OLDS 4-4-2: TRI-POWER ROCKET! was a serious Supercar. Taking it up a notch, it was available with a W-30 option that didn’t change the factory power rating, but unquestionably improved quarter-mile performance. Key W-30 ingredients included a chromed Tri-Carb air cleaner with four-inch hoses ducting fresh air from front bumper openings, a high-lift, 308-degree-duration camshaft, and relocation of the battery to the trunk. The majority of W-30 engines were in base model F-85 4-4-2 Club Coupes.
For complete details on the ’66 OLDS 4-4-2: TRI-POWER ROCKET!, 4-4-2 road tests, tech data, please visit OVER-DRIVE magazine @ https://over-drive-magazine.com/2023/12/30/1966-oldsmobile-mid-size-cars-fact-sheet/
Hurst Performance volunteered to sponsor and pace the 1972 Indy 500, and it was the only time a Pace Car was supplied from other than a major automobile manufacturer. For Indy, an additional six station wagons were constructed for press and ambulance use, though not considered true Hurst Oldsmobiles, and 279 of the hardtop cars were made available and later sold. All cars were Cameo White with reflective gold stripes that were stick-on decals, not paint. All cars had the W-25 Ram Air Hood and gold SS III Rally Wheels with a chrome bolt-on center cap and chrome beauty ring. The tires were unique to the car: Goodyear Polysteel Radials.
The base Hurst/Olds engine was the L75 455-inch V-8 rated at 250 SAE net horsepower. Optional at extra cost was the W-30 option with the L77 455, above, and typical of Oldsmobile at the time, it was a massaged special-build engine rated at 300 SAE net horsepower. Engines were mated to Turbo Hydra-Matic 400 transmissions with console-mounted Hurst Dual-Gate shifters. (There were no manual transmission cars.) All Hurst/Olds were fitted with black Strato-Bucket seat interiors with center consoles and Dual-Gate Shifters, as well as “Digital Performance Computers”.
The Lansing Engineering facility was down the road from Demmer Tool & Die, a GM supplier. There was a lot of “information” sharing between Olds and Demmer drag racing engineers. Demmer raced a Tri-Carb 4-4-2, RECTIFIER-2, and worked closely with Oldsmobile. In 1968 Demmer built the 455-inch Hurst Olds. Unlike GTO Tri-Power with vacuum-operated linkage opening the end two Rochester 2GC carburetors, the ’66 OLDS TRI-POWER 4-4-2: SERIOUS SUPERCAR L69 Tri-Carb utilized smoother, progressive mechanical linkage.
With a choice of Anti-Spin gearing up to 3.90 and dealer-installed 4.11 or 4.33 gears, plus close or wide-ratio Hurst-shifted four-speeds, the Tri-carb 4-4-2 was a serious Supercar. Taking it up a notch, it was available with a W-30 option that didn’t change the factory power rating, but unquestionably improved quarter-mile performance. Key W-30 ingredients included a chromed Tri-Carb air cleaner with four-inch hoses ducting fresh air from front bumper openings, a high-lift, 308-degree-duration camshaft, and relocation of the battery to the trunk. The majority of W-30 engines were in base model F-85 4-4-2 Club Coupes.
Finished in brilliant yellow with red stripes, our 4-4-2 was noticeably slower than the gold car. Our best times were 98 mph in 14.30 seconds at the track and 7.5 seconds sprinting to 60 mph. With a great Rally Sports suspension, beefy sway bars, and variable-ratio power steering, the 4-4-2 was a great road car.