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3800 History

The first 3.8 liter Buick V-6's came out in the early 60's,...the uneven firing order produced a rough idling engine, not many were sold, and the design was sold to AMC Jeep in '67(several '67 Jeep CJ's and other models had the 'new' 3.8 liter V-6),....Buick bought back the design in '74,and punched out the bore to 3.800 inches(thus the 3800 engine was born and 'reintroduced' in Buicks in '75),....still with it's uneven firing order until mid-year '77(some '77 3.8's were produced as uneven and some were even) when Buick revised the crank throws. SEVERAL major upgrades/revisions were done to the engine since then, making it one of the most largely produced and popular motors in GM (and All of automotive) history

The first 3.8 was offered in 1975 on the Skyhawk, Apollo, and Century/Regal. It was even offered in the LeSabre in 1976! In 1976 the LeSabre was huge at 227 inches and 4200 pounds! The 3.8L made 110 horsepower.  The first American V-6 was introduced by Buick for 1962. It was simply a Buick V-8 with two cylinders chopped off. So, actually the 3800 can be traced all the way back to 1953 when Buick made their first V-8.

Buick's final turbocharged V-6 was built in 1987 because something better was in the offing. Engineers had concluded that a supercharged V-6 offers an excellent combination of virtues: compactness, durability, reliability, fuel efficiency, smoothness, and plenty of power potential. Efforts to perfect a modern supercharger for automotive use began at Eaton Corp. in 1977 between the first and second energy crises. By 1991, both Buick and Eaton were ready to introduce what has become the most successful supercharged automotive engine in history.

Since it was reintroduced for the 1975 model year, the Buick 3800 V-6 has enjoyed continuous refinement:

  • Adoption of a split-pin crankshaft facilitated smoother even firing in 1977.
  • Larger valves and new intake and exhaust ports raised power in 1979.
  • Direct fire ignition and electronic port-type fuel injection were added in 1984.
  • Single-serpentine-belt accessory drive was introduced in 1985.
  • Reduced-friction, roller-type hydraulic lifters and sequential fuel injection came in 1986.
  • Low-drag piston rings, digital exhaust gas recirculation, direct-impingement fuel-injection targeting, and a quick-start ignition were added in 1988. A new counter-rotating balance shaft eliminated the first-order imbalance.
  • Tuned-port induction boosted horsepower and torque in 1990.
  • Roller rocker arms, a higher compression ratio, and reduced piston ring tension improved efficiency in 1993.

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

Delivering a supercharged engine that's 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's 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's balance of supercharged performance and efficiency beats virtually every V-8-powered automobile on the U. S. 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.





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