1997 BUICK POWERTRAINS
FLINT, Mich. -- Buick's powertrain lineup is improved for 1997. Advancements in electronically controlled automatic transmissions are designed to set new standards for smooth shifts and reduction of noise and vibration, while contributing to fuel economy.
In recognition of engineering excellence, both the normally aspirated and supercharged 3.8-liter 3800 Series II V-6s were named among the "Ten Best Engines of 1996" by Ward's Auto World.
3800 SERIES II AND SUPERCHARGED 3800 SERIES II V-6 (L36 and L67)
Road & Track magazine said, "The power hungry will revel in the big 3800 Series II V-6. "
The Series II V-6 is standard equipment in the 1997 Park Avenue, Riviera and LeSabre, as well as the '96 Regal Limited and Gran Sport (and optional in '96 Regal Limited.) This normally aspirated 90-degree V-6 displaces 3791 cc (231 cubic inches) and has a cast-iron block and cylinder head. Induction is via sequential electronic port fuel injection. The engine is rated at 205 horsepower at 5200 rpm and 230 lb-ft of torque at 4000 rpm. Its compression ratio is 9.4:1.
The supercharged 3800 Series II is standard in Park Avenue Ultra and available in Riviera. Output is boosted to 240 horsepower at 5200 rpm and 280 lb-ft of torque at 3200 rpm. Its compression ratio is 8.5:1. Maximum engine speed for both engines is 6000 rpm. In Park Avenue, projected fuel economy ratings are 19 miles per gallon city and 29 mpg highway; the supercharged Ultra's ratings are 18/27. In LeSabre and Regal, the 3800 Series II is rated at 19/30.
In both engines, the bore and stroke is 3.80 x 3.40 in. (96.52 x 86.36 mm). Induction to symmetrical combustion chambers is through high-flow injectors to one intake and one exhaust valve per cylinder, with hydraulic roller lifters. Exhaust is ducted through tubular stainless steel exhaust tubes with dual rear outlets. Both engines are fully OBD-II compliant.
Both engines have long-life spark plugs and coolant fluid, a balance shaft to reduce vibration, and optimized engine mounts, now with dual-durometer torque-reaction engine mounts instead of single durometer units, resulting in a reduction of discernible idle buzz.
New for '97: The 3800 Series II benefits from improved engine sealing, upgraded with a totally redesigned front-rear intake to the cylinder block end seal; the supercharged version's exhaust system has been enhanced for improved sealing to meet '97 OBD-II regulatory requirements. A major improvement: The use of a flexible coupling between the downpipe and the catalytic converter, for even greater durability.
3100 V-6 (L82)
The Consumers Review Car Buyer's Guide of '96 model cars refers to the 3100 V-6 this way: "This engine...has significantly more low-rpm torque for better off-the-line performance, and is much smoother under normal driving conditions. "
The overhead-valve 3.1-liter is standard equipment in Skylark Gran Sport, Century Custom and Limited and Regal Custom. It's available in Skylark Custom and Limited models.
The six-cylinder engine displaces 3136 cc (191 cubic inches). Its revised block design features a stiffened skirt that deadens vibration for a smoother, quieter ride. The block is cast iron, and both the cylinder head and intake manifold are cast aluminum, the improved intake manifold yields significant noise reduction. Bore and stroke are 3.51 x 3.31 in. (89.0 x 84.0 mm). Compression ratio is 9.6:1. Power output is 160-horsepower at 5200 rpm (except in Skylark, where output is 155 horsepower due to induction differences) and torque is 185 lb-ft at 4000 rpm. Maximum engine speed is 6000 rpm. Projected fuel economy is 20 mpg city, 29 highway.
Fuel is delivered via sequential electronic fuel injection. Each cylinder has one intake and one exhaust valve. A "24X ignition" provides a smooth idle. The system sends 24 crankshaft reference signals to the powertrain control module (PCM) for each crankshaft revolution. This ensures more precise monitoring of engine position and improves spark delivery, yielding enhanced driveability and better exhaust emission control at low rpm levels.
New for '97: Improved PG 260-FI starter is smoother, quieter and more reliable; camshaft reliability is enhanced by changing the thrust plate material to powdered metal and the cam journal to cold-formed steel; a one-piece flywheel is slightly heavier but better quality with improved reliability and durability; increased coolant flow to the heater results in a better warm-up profile; emissions reliability is improved with a more powerful powertrain control module, enhanced evaporative emission system, new spark plugs, new fuel pressure regulator, a mass air-flow sensor, linear EGR, new oxygen sensor, MAP sensor and leaf-free flex exhaust coupling.
TWIN CAM L-4 (LD9)
Road & Track said of this engine, "Power-hungry drivers should consider the 2.4-liter Twin Cam, a completely redesigned engine that's not only smoother and quieter than [the] Quad 4 but provides improved acceleration."
This is the standard engine in Skylark. This dual overhead camshaft 2.4-liter engine displaces 2392 cc (146 cubic inches). Bore and stroke is 3.54 x 3.70 in. (90.0 x 94.0 mm) and the compression ratio is 9.5:1. Output is 150-horsepower at 5600 rpm and 155 lb-ft of torque at 4400 rpm. Maximum engine speed is 6500 rpm. Sequential electronic fuel injection provides fuel to four in-line cylinders through steel injectors for resistance to corrosion from alcohol-additive fuels. Induction is through two intake and two exhaust valves per cylinder, actuated by dual overhead camshafts. Fuel economy is rated at 22 mpg city, 32 highway.
The block is cast iron, the cylinder head is cast aluminum and the intake manifold is a light injection-molded composite plastic with sound deadening properties. Platinum-tipped spark plugs are designed for 100,000-mile serviceability, and electronic spark control (knock sensing) allows the calibration to run closer to the optimum spark timing without risking detonation.
The engine coolant system features an "inlet thermostat." This greatly improves heater performance in cold-weather environments, but also benefits cooling performance in hot weather. Engine durability is enhanced by reducing stress caused by the thermal cycling of a pressure-side thermostat.
Accessories such as the air conditioning compressor are mounted directly to the engine; elimination of mounting brackets eliminates potential vibrations and noise. Smooth and quiet performance in the important mid- and high-speed driving ranges is ensured with a unique "in-oil pan" design balance shaft system. The power steering pump is a direct-drive type driven off the intake camshaft, replacing a system utilizing two pulleys, one belt, two brackets and numerous fasteners.
New for '97: An improved and simplified PCM adds four times the computing power with half the previous number of components. The result is increased diagnostic capability and improved powertrain control at a lower cost.
NEW TRANSMISSIONS: 4T65E and 4T65E HD
A sophisticated new version of the 4T60E four-speed automatic transmission is matched to the 3800 Series II V-6 engine. The transmission is titled the 4T65E with EC3 -- Electronically Controlled Capacity Clutch. The fuel economy benefits supplied by this transaxle development are as great as the change from a three-speed to a four-speed automatic. An average three percent fuel economy gain is achieved on vehicles equipped with the new transmission, due to the new capacity clutch, electronic line pressure controller and a larger torque converter. The 4T65E is the standard transmission in Park Avenue, Riviera and LeSabre. The higher-capacity 4T65E HD (heavy duty) is fitted to the supercharged Riviera and Park Avenue Ultra.
More than 70 percent of the components of the 4T65E are new. Every major external component is new, including the torque converter, cast aluminum case and side cover. The new composite friction material on the torque converter pressure plate acts similar to a viscous clutch, in that a minute amount of slippage is built in for smoother shift events. In addition, the transaxle locks up at lower vehicle speeds for improved fuel economy. The result is a balanced package designed for greater durability, reliability and operating smoothness.
A full complement of electronic controls adjusts shift quality and adapts to changing conditions for significantly improved shift feel. The transmission is in full compliance with OBD-II regulations. Because it's filled for life with DEXRON-III fluid, it never needs service under normal operating conditions.
If a driver manually selects low gear but fails to upshift at high speeds, the PCM protects the engine from over-revving by automatically upshifting to second gear. Should the transmission suffer an unlikely failure, "limp-home" programming ensures the driver is never stranded.
The 4T65E HD transmission provides a heavy-duty gear set and larger shafts and pinions to accommodate the higher torque of the supercharged V-6.
