Buick V6 engine


The Buick V6 is an OHV V6 engine developed by the Buick division of General Motors and first introduced in 1962. The engine was originally and was marketed as the Fireball engine. GM continued to develop and refine the V6, eventually and commonly referred to simply as the 3800, through numerous iterations.
The 3800 made the Ward's 10 Best Engines of the 20th Century list and made Ward's yearly 10 Best list numerous times. It is one of the most-manufactured engines in automotive history, with over 25 million produced.
The engine originally derived from Buick's aluminium V8 family, which also went on to become the Rover V8, manufactured from 1960–2006.

Overview

The 3800's block is cast iron and all variants use iron, two-valve-per-cylinder OHV heads. The engine, originally designed and manufactured in the United States, was also produced in later versions in Australia. It was the first six-cylinder engine designed exclusively for Buick products since the Buick straight-six was discontinued in 1930.
In 1967, GM sold the design to Kaiser-Jeep since they no longer felt the need to produce a V6, considered an unusual engine configuration in North America at the time. The 1973 oil crisis prompted the company to re-acquire the design from American Motors, who had purchased Kaiser-Jeep in 1970, in early 1974. The descendants of the early 231 continue as the most-common GM V6, as it developed into a very durable and reliable design.
Though the pre-3800 rear-wheel drive V6 uses the Buick, Oldsmobile, Pontiac bellhousing pattern, an oddity of both the front-wheel drive and RWD 3800 V6 is that although it is a 90° V6, it uses the GM 60° V6 bell housing. For use in the FWD applications, the bellhousings on the FWD transmissions are altered slightly.
This engine has the cylinders numbered 1-3-5 on the left-hand bank and 2-4-6 on the right-hand bank, the number 1 cylinder being the furthest from the flywheel end. The firing order is 1-6-5-4-3-2.
The engine was produced at the Flint North plant in Flint, Michigan, with engine blocks and cylinder heads cast at the Grey Iron plant at 1629 N. Washington Avenue in Saginaw, Michigan.

Early versions

Fireball V6

The first engine in this family, RPO code 6I, was introduced in 1961 for the 1962 model year Buick Special with Buick's engine, the first V6 in an American car. Because it was derived from Buick's aluminum V8, it has a 90° bank between cylinders and an uneven firing pattern due to the crankshaft having only three crank pins set at 120° apart, with opposing cylinders sharing a crank pin in, as do many V8 engines. The uneven firing pattern was often perceived as roughness, leading a former American Motors executive to describe it as "rougher than a cob."
The off-center design continued up until the 1988 LN3 version of the engine, when the left-hand bank of cylinders was moved forward relative to the right-hand bank. Although the actual bore spacing between cylinders on the same bank remained unchanged at, the LN3 and later engines became known to have "on-center bore spacing".

198

The Buick Division, concerned about high manufacturing costs of their innovative aluminum 215 V8, sought to develop a cheaper, cast-iron engine based on the same tooling. It was given the RPO code JL. They settled on an unusual 90° V6 layout that was essentially the architecture of the '215' less two cylinders. In initial form, it had a bore and stroke of, for an overall displacement of. It weighed about more than the aluminum engine, but was less costly to manufacture. Dubbed the Fireball V6, it became the standard engine in the 1962 Buick Special. In their test that year, Road & Track was impressed with Buick's "practical" new V6, saying it "sounds and performs exactly like the aluminum V8 in most respects."

225

The bore was increased to, and stroke increased to, increasing displacement to. The engine was similar to the popular small-block Buick V8—now with a cast-iron block and displacement of, the engine was made at the same factory with much of the same tooling. This engine carried the RPO code KH for the 1964 model year and LH for 1965. In 1966, the code was MH and was renamed the Wildcat V-6. For 1967, the code was NH. This engine was used in Buick's intermediate-sized Special and Skylark models from 1964 to 1967 and Oldsmobile's mid-sized F-85/Cutlass models for 1964 and 1965, including the Oldsmobile Vista Cruiser and Buick Sport Wagon.
1964–1965 models featured a single barrel Rochester MonoJet, producing. In 1966–1967, the 1-barrel was replaced with a 2-barrel Rochester 2GV, giving the engine a 5-horsepower boost to.
The V6 was dropped after the 1967 model year in favor of a conventional inline-six engine built by the Chevrolet division, and the tooling was sold to Kaiser-Jeep.

Dauntless

In 1965, Kaiser-Jeep began using the Buick 225 in Jeep CJs. It was known as the Dauntless V6 and used a much heavier flywheel than the Buick version to damp the vibrations resulting from the engine's firing pattern. Buick sold the tooling for this engine to Kaiser in 1967, as the demand for the engine was waning steadily in an era of V8s and muscle cars. When American Motors bought Jeep, the V6 was replaced with AMC straight-6 engines, but the ownership of the V6 tooling remained with AMC.
The 1973 oil crisis prompted GM to look for more economical engines than the V8s of 350, 400, and 454/455 cubic inches that powered most General Motors cars and trucks during that time. At that time, the only "small" engines generally offered by GM were built by the Chevrolet division including the OHC aluminum inline-four engine used in the subcompact Chevrolet Vega and a straight-6 used in smaller Chevy, Buick, Oldsmobile and Pontiac models, whose design roots dated back to the 1962 Chevy II. LD5 was the RPO for engines with chassis code "A", LD7 was used for the 1977-only VIN code "C" engines.
One quick idea was tried by Buick engineers—taking an old Fireball V6 picked up at a junkyard and installing it into a 1974 Buick Apollo. The solution worked so well that GM wanted AMC to put the engine back into production. However, AMC's cost per unit was deemed as too high. Instead of buying completed engines, GM made an offer to buy back the tooling and manufacturing line from AMC in April 1974, and began building the engines on August 12. With production back within GM, Buick re-introduced the V6 that fall in certain 1975 models—a move made possible by the fact that foundations for the old V6 machinery were still intact at Buick's engine assembly plant in Flint, Michigan, so it was easy to put the old tooling back in place and begin production at least two years ahead of the normal schedule that would have been required to create new tooling. The bore was enlarged to, identical to the Buick 350 and Olds 307 V8s, yielding displacement. 78,349 units were installed in Buicks for 1975.
To meet the challenges of the new fuel economy and emissions standards, the engine produced just, depending on fitment and year.
In 1977, Buick redesigned the crankshaft to a "split-pin" configuration to create an "even-firing" version. The crank pins associated with the opposing cylinders were offset from each other by 30°. The relatively small offset did not require flying arms to be incorporated, however a thick flange was built in between the offset crank pins to prevent the connecting rod big-ends from "walking" off the crank pin bearing journal and interfering with the adjacent big end. The thick flange effectively caused the connecting rods on the left-hand bank of cylinders to move forward and the right-hand bank to move rearward, but the engine block remained unchanged compared to the odd-fire engine. Since the cylinders center-lines were no longer centralized over the crank pin bearing journals, the connecting rods were re-designed with the big-ends offset from the piston pin ends by. The engine in this configuration became known to have "off-center bore spacing".
In 1978, GM began to market the 231 as the 3.8 liter as metric engine sizes became common in the United States. The RPO Code was LD5, though California-emissions versions were called LC6. Starting in 1979, the engine was used in the front-wheel drive Buick Riviera, though still with a longitudinal mounting. Larger valves and better intake and exhaust boosted the power output for 1979.
A turbocharged version was introduced as the pace car at the 1976 Indianapolis 500, and a production turbo arrived in 1978. The turbo 3.8 received sequential fuel injection and a wasted spark Distributorless Ignition System in 1984. In 1986, an air-to-air Garrett intercooler was added and the RPO Code became LC2. The LC2 engine has a bore and stroke of. The horsepower ratings for 1986 & 1987 were, respectively. The limited production GNX benefitted from additional factory modifications such as a ceramic turbocharger, more efficient Garrett intercooler, low restriction exhaust system and revised programming which resulted in a factory rating.
The turbocharged 1987 Buick Regal Grand National GNX was called America's quickest automobile, and the model continues to be collected and appreciated today.