The Life and Times of the Buick V6
The Little Engine That Could!

The venerable Buick 3.8 V6 has had a long and fairly illustrious career, powering many Buicks, and other GM vehicles over the past 30 years. The original design for the V6 started in the early 60s when Buick created a V6 based on the all aluminum 215 V8. The very first "Fireball" V6 displaced a whopping 198 cubic inches and shared tooling with the 215 aluminum V8 in 1962. In late 1963, the bore was increased to be the same as the 300 V8, which made displacement 225 cubic inches, where it stayed until 1967. Since the V6 had the same bore as the 1966 340 V8 it could be produced on the same assembly line. This made it cheap and easy to produce for the "compact" cars in GM's car lines. The demand for the V6 was never very great and the design resulted in an uneven firing order that produced a rough idling engine, so the design was sold to Jeep in 1967.

In the 70s, with the advent of the gas crisis and the demand for a versatile, lightweight, and inexpensive engine, Buick bought the design back from Jeep in 1974. The little V6 was reworked so that it could be made on the same assembly line as the Buick 350, which entailed making the bore 3.800". Using this bore size, it could share pistons and other parts with the V6. This engine retained the original designs "odd-fire" design.

In 1977, Buick redesigned the firing order to make it a smoother running engine by revising the crank throws. This was a mid-year change, so some odd-fire and some even-fire V6s were made during 1977. The new even-fire engine still retained the same bore spacing as the odd-fire version, so the bores were no longer centered over the rods and the engine had to be under balanced and soft motor mounts were used. The balancing took care of the vertical component of the vibrations and the motor mounts took care of the horizontal component.

Several variations of the 231" V6 were made over the years, including the 3.0 liter in some of the early 80s front wheel drive cars, the 4.1 liter used in some of the larger rear wheel drive cars, and of course, the turbo 3.8 variations used in the various Sport Coupes, turbo Regals, some early '80-81 Monte Carlos, and some of the Riviera's.

This article will concentrate on the 3.8 versions, since that's more relevant to those of us with the turbo cars. The basic design for the engine that went into the turbo Regals really didn't change much from late 1977 until 1987. The blocks had slight revisions up until 1986-87, mainly to increase oiling and to revise the deck heights to allow the use of thicker composition head gaskets. One of the biggest changes was in 1985, when the oil pans went to 20 bolt oil pans instead of 14 bolt oil pans.

All in all, there were a lot of the 3.8s produced, due to it's many virtues. The availability of basic mechanical parts is still very good and many specialty parts for the GN/turbo Regal turn up as new parts for other car models with the 3800 (a redesigned 3.8), such as the Reatta. Below is a history of the V6, followed by a chart cross referencing some of the blocks/cranks/heads used over the years that was derived from the March 1994 issue of Automotive Rebuilder.

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

Block, Head, Crank - Part Numbers

Application Year Block Head Crank
3.8L RWD
1975-76 1249432 . .
3.8L RWD
1977 1254083 1237722 1257125
. . 1255862 . .
. . 1232438 . .
3.8L RWD
1978 1261438 1257661 1260877
. . 1261787 1257051 2551229
. . 25505554 . .
Turbo RWD
. 1261438 1257661 Rolled Fillets
3.8L RWD
1979 1261787 1262098 25500229
. . 25505554 25504443 .
Turbo RWD
. 25514290 25504443 .
. . 25505554 25504443 Rolled Fillets
3.8L RWD
1980-81 25506818 25505900 See 1978
. . 25506293 .
Turbo Monte/Regal
. 25506818 25505900 See 1978
. . 25506293 .
Turbo Riviera
. 25506818 25505900 See 1978
. 25506485 25506293 .
3.8L RWD
1982 25506818 25510191 See 1978
. . . 25514290 .
Turbo Regal
. 25506818 25510191 See 1978
. . . 25514290 .
Turbo Riviera
. 25506481 25510191 See 1978
. . 25524289 . .
3.8L RWD
1983 25524289 25518445 See 1978
25506397 . .
Turbo Regal
. 25524289 25518445 See 1978
Turbo Riviera
. 25524289 25518445 See 1978
3.8L RWD
1984 25524290 25518445 See 1978
. . 25528601 . .
. . 25520040 . .
Turbo Regal
. 25520040 25518445 See 1978
. . 25518603 . .
Turbo Riviera
. 25520040 25518445 See 1978
. . 25520042 . .
. . 25528603 . .
3.8L RWD
1985 25524140 25518445 See 1978
. . 25520329 . .
Turbo Regal
. 25520329 25518445 See 1978
Turbo Riviera
. 25520231 25518445 See 1978
FWD (Flat lifters)
. 25520043 25518445 25514267
3.8L RWD
1986 25526109 25518445 See 1978
Turbo Regal
. 25526109 25518445 See 1978
FWD Flat Lifters
. 25526110 25524248 25514267
FWD Roller Lifters
. 25526111 25524248 25514267
3.8L RWD
1987 25526109 25518445 See 1978
Turbo Regal
. 25526109 25518445 See 1978
FWD Roller Lifters
. 25526110 25524248 25514267
. . 25526111 25529889 25527515
FWD Roller Lifters
1988 25528801 25527515 25514267
FWD 3800 Roller
. 25532617 25529723 25530502
. . . 25522646 .
3800 FWD Roller
1989 25528801 25527515 25514267
Turbo Trans Am
. 25526109 25536702 25511229
3800 FWD Roller
1990 25531617 25534250 25530502
. . . 25532646 .
3800 EV6
. 25532674 25534250 25534737
4.1L RWD
1968-1972 3877178 3895052 .
. . 3850817 3927763 .
4.1L RWD 1973-1976 366855 3962084 .
. . 348675 14002012 .
. . 328575 370696 .
. . 743483 355795 .
. . 358675 377133 .
4.1L RWD 1980-1984 25506484 25504443 .
. . 25505553 25505900 .
. . 25514291 25506293 .
. . . 25518445 .


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