Quick History and Information about the GM 60° V6
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informative purposes only. GM and all related product identities, etc. are property
of GM. If you find an error in this information, or have comments, please contact
us.
The 2.8L 60° V-6 Engine was designed by Chevrolet and introduced in 1980
in the X-car platforms. These included the front-wheel-drive (FWD) Buick Skylark,
Chevrolet Citation, Oldsmobile Omega, and Pontiac Phoenix. It was designed to meet
federal fuel economy standards, new emmisions laws, and to provide a suitable powerplant
for smaller vehicles. Eventually, this engine found homes in Camaros, S-10 Blazers,
S-15's, Fieros, Cimmarons, Centurys, Firebirds, Jeeps, Isuzus, and even Mercury Marine.
The 60° V-6 engine's cylinders were offset 60° from one another due to
space limitations. Over the years, the 60° V-6 engine has proven to be a reliable
engine in many applications. It began as a 2.8L, then was changed to a 3.1L, and
finally to the 3.4L displacement. Throughout the years, there have been a
variety of motor mount , fuel pump location, ignition system, transmission mount, balance,
fuel delivery system, oiling system, and other changes.
The evolution of the 60° V-6 brought larger displacement and more
sophisticated engineering. The engine was so extensively changed in 1987, that the
new model was referred to as the "Generation II" engine. Improvements
included aluminum cylinder heads with splayed intake and exhaust valves, improved intake
porting, tighter operating clearances, distributorless ignition, a single serpentine belt
drive system for accessories, and numerous engine appearance improvements. The
Generation II Engine was only available in FWD vehicles.
In 1991, the 3.4 dual overhead cam (DOHC) with four valves per cylinder
version was introduced. This engine design included major improvements, with a base
horsepower rating of around 210.
There are many differences between the FWD, Mid-Mount, and RWD engines,
besides the different mounting locations. The cooling systems, water pump location,
cylinder heads, and intake manifolds are some of the major items that need to be taken
into account if you are intending doing a direct swap.
Here is a list that documents the changes GM made to this platform through
the years:
1980
- Introduction of the 2.8L/173 c.i.d. 60° V-6.
- 60° cylinder angle in block for size reduction.
- Was designed for future displacement increases
- Firing order is 1-2-3-4-5-6
- Short Stroke Design (89mm Bore, 76mm Stroke)
- Small Main Journal Design
- Cast Iron, Small Valve Heads (1.60 Intake, 1.30 Exhaust)
- Flat-top aluminum cast pistons
- Fuel pump pushrod 12mm in diameter
- HEI ignition system
- 2-barrel Rochester Varajet II carburetor
- Externally balanced cast crankshaft
1981
- Water Pump/Timing Cover changed to accomodate not having to remove timing
cover seal when removing watr pump.
- Guide mounted seal added to intake valve guide
- Early Fuel Evaporation grid added underneath carburetor
- HO version introduced (HP increase to 135, piston height increased, compression
increased to 9.0:1, Intake and
exhaust valve diameters increased, cross-drilled crankshaft main journals)
1982
- Basic carry-over from 1981
- First use in RWD vehicles
- Fuel pump pushrod diameter increased to 16mm in all models
- Rope-type rear main seal replaced by two-piece polymer seal
- Front mounted thermostat housing in RWD models
- EGR valve located at rear of engine in RWD vehicles
- RWD vehicles had engine-driven cooling fan
- HEI distributor with separate coil in RWD vehicles
1983/1984
- Basically carried over from 1982 model year
- Once pice rear main seal
- Four-bolt right hand motor mount
1985 (Major Changes in Mid-Year)
- Switch-over year to larger main journal blocks mid-year
- Engine introduced in J-cars
- Thing front timing cover, offset waterpump, and narrower timing set used in models with
engine set further forward (i.e.
Cavalier, Cimmaron, etc.)
- Multiport Fuel Injection (MPI) system was introduced, which included: one fuel injector
per cylinder which sprays fuel
directly into cylinder, cold start fuel injectors, special throttle body,
high-pressure electric fuel pump, fuel pressure regulator.
- Different cylinder head gaskets and pistons used with MPI engines
- One-piece rear main seal introduced (10mm wide) mid-year
- O-ring used to seal main oil passage between oil pump and block
- Distributor downsized
- Serpentine accessory drive belt on some models.
- Lower friction oil control rings
- Intake manifold plenum lowered in J-cars to clear hood
1986
- Carry over from 1985
1987
- Generation II engine introduced in FWD vehicles.
- Cylinder heads redesigned, changed to cast aluminum instead of iron
- Cylinder heads modifications required use of dished pistons and different
head gaskets
- Cylinder heads designed with splayed intake and exhaust valves
- Cast aluminum valve covers
- Guide mounted oil seals used on both intake and exhaust valves
- Discontinued use of valve stem seal, oil shedder, and shield
- Valve lash adjustment procedure changed
- Intake plenum, front timing cover, and water pump housing redesigned
- Direct Ignition System (DIS) replaced distributor
- Internally balanced crankshaft incorporates "reluctor" wheel for
distributorless ignition system
- Compression ratio increased to 8.9:1
- Lower friction piston compression rings used
- Model 700 TBI introduced
- Serpentine accessory drive belt
- One-piece oil pan gasket
1988
- Used lathe-turned pistons
- Piston weights reduced
- Internally balanced crankshafts in RWD vehicles only
- New type fuel injectors
- Speed density engine control system replaces mass-air flow sensor in J-cars
1989
- Carry over year
1990-1992
- Displacement increased from 2.8L to 3.1L
- Uses dished pistons
1993
- 3.4L pushrod version introduced in Camaro and Firebird
- Bore increased
- SFI system introduced
- DIS system introduced
- Cylinder block upgraded
Well, hopefully this gave you some information about the history of this
engine. There has been both a pushrod and DOHC version of the 3.4 in the late 80's
and early 90's. ARI offers stroker kits for the 2.8L and 3.1L engines, as well as
providing a variety of machine shop services and performance parts for all of the GM 60°
V-6 Engines.
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