In 1995, Buick thoroughly overhauled the successful 3800 V-6 in anticipation of rising customer expectations. The latest advancements in design, materials, and manufacturing were invested in the new engine, now designated 3800 Series II V-6.

Key features are as follows:


A low deck height cylinder block trims 8.8 pounds of weight and reduces the exterior dimensions.
Cross-bolted main-bearing caps and a deep-skirt design improves stiffness to reduce noise radiated from the engine.
Lightweight pistons with floating pins and low-tension rings in combination with shorter cast-steel connecting rods reduce reciprocating mass and internal friction.
More rigidly mounted external accessories (alternator, power steering pump, AC compressor) are smoother and quieter in operation.
Replacing the balance shaft'* front roller bearing with a pressure-lubed sleeve bearing reduces noise.
Cylinder heads with symmetric ports and combustion chambers balance power output, improving smoothness and reducing emissions.
Larger valves, less restrictive intake and exhaust ports, a larger throttle body and mirror-smooth passages in the molded composite intake manifold improve volumetric efficiency. Lighter, stiffer valvetrain components facilitate a 6000-rpm redline.
More aggressive valve timing improves both low and high rpm output.
Horsepower, torque and fuel efficiency are improved by a higher 9.4:1 compression ratio.
The addition of dual knock sensors permits optimum spark timing and protection against detonation.
Oil pan, crankshaft, and water pump seals are improved to yield a lifetime leak-free engine.
A constrained-layer oil pan design (sound-deadening material between two layers of steel) quiets noise at the bottom of the engine.
Exhaust manifolds and connecting pipes are designed to minimize the radiation of both heat and noise for quiet operation and rapid warm-up of the catalytic converter.
A foam-lined top acoustical cover mutes injector click and intake system noise.
Nearly all of the Series II refinements invested in the normally aspirated 3800 V-6 were passed on to the supercharged version in 1996. In addition, the supercharger'* internal displacement was increased from 62 to 90 cubic inches. Driving the blower 1.8 times faster than crankshaft speed yields a maximum full-throttle boost of 7.5 psi and impressive output: 240 horsepower at 5200 rpm and 280 lb-ft of torque at 3600 rpm.

That'* more torque than any other manufacturer offers in a six-cylinder engine, including Porsche'* new 911.

Delivering a supercharged engine that'* as smooth, quiet, efficient, and trouble-free as the 3800 Series II is no easy feat. The entire powertrain must be treated as one interrelated system to meet a long list of demands without compromise.

The air induction tract must be tuned from the mouth of the air cleaner all the way to the intake valve for quiet operation with maximum performance.

Two helmholtz resonators eliminate induction boom. Cavities are also positioned in the supercharger'* cast aluminum housing to quiet induction noise. Each rotor has three lobes which are twisted 60 degrees along their length to smooth pressure build up and air flow. These extruded-aluminum rotors are powder-coated with epoxy for lifetime durability.

Since the rotors seal without contact, there is no chance for wear in normal service. An axial entry port at the rear of the housing and a bottom exit port are carefully configured to hush the siren sound with no loss of flow capacity.

Sealed lubricant reservoirs at both ends of the supercharger provide lifetime maintenance-free reliability. During idle and cruise operation, a valve controlled by the powertrain computer bypasses intake air around the supercharger to minimize drag.

That helps deliver excellent fuel efficiency: The Buick Regal GS achieves 18 mpg in EPA city driving and 27 mpg in highway ratings. The Buick Park Avenue Ultra and the Riviera both score 18 mpg in the city and 27 mpg on the highway. Buick'* balance of supercharged performance and efficiency beats virtually every V-8-powered automobile on the U. *. market.

In summary, the supercharging road is long and winding with side trips high into the sky. But this much is inarguable: supercharging the 3800 V-6 engine is a marriage made in engineering heaven.

More on the '95 L36 GM 3800 V6: block is 11 pounds lighter, rods are .64 inches shorter, pistons are different, the main caps are powder metal, the balance shaft now has a plain bearing in back instead of a roller, a windage tray has been added, pistons have floating pins, dual knock sensors are used, new ports and "symmetrical" combustion chambers, lighter valve, investment-cast rockers.