Chevy 60 degree V6 Engine

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Fiero Engine Info

"Are there casting marks or numbers which would verify that a block in a Fiero actually started out in a Fiero?"

Engine Stamping Information

1985   2.8   CBX, CBY
1986   2.8   DAF, DAH, DBN
1987   2.8   SCN, SCP
1988   2.8   CFC, CFD

Engine number location: front of block below right cylinder head.

General Information


The 2.8L V6 was used in many GM vehicles, both FWD and RWD. There are differences in the engine and accessory mounts between the FWD and RWD versions of the engine, so the two are not interchangable.

There are two versions of the "First Generation" 2.8, a regular version producing around 110hp and a high output version producing 135-140.

All V6 Fieros come equipped with the L44 High Output V6.

High-Output engines have higher compression (8.5:1 to 8.9:1), bigger valves and higher lift cams. (NOTE: all fuel-injected 2.8s have the bigger valves)

                    Standard              High-Output (F.I.)
Valve size          1.60" intake          1.72" intake
                    1.30" exhaust         1.42" exhaust

Dur @ .050          178 intake            196 exhaust
                    196 intake            203 exhaust

Cam lift            .347 intake           .394 exhaust
                    .394 intake           .410 exhaust

From: Scott Backer

Sometime in 1985, Pontiac switched block types. The 3.1 crankshaft has an extra "lobe" or something, which is used for crank timing, which the 3.1 engine uses. The Fiero 2.8 does not use crank timing. This extra "lobe" will hit the block if installed on earlier non-compatible blocks.

The later blocks, which are compatible with the 3.1 cranks are labelled 459T on the side of the block. These are roughly 1 inch high letters, cast right in the side of the block. If you are increasing displacement, make sure your block is compatible for upgrading before you buy parts kits.

From: Paul Millette


"Generation II" 60-degree V6 with aluminum heads introduced. Only used in FWD models. The aluminum heads have splayed valves and replicated ports to increase efficiency and power. Dished pistons are necessary to keep the piston from hitting the valves, and the compression ratio increased from 8.5:1 to 8.9:1.

From: Sketch

"There is a crankshaft position sensor on my block. I do not have a connector for it on my wire harness. Are the other V6's like this or is my connector missing?"

Later model V6's have the crankshaft position sensor. The Fiero motors did not use this sensor.

From: Lee Brown

1985-87 FLYWHEEL (w/manual trans)    476575    $174.00
1985-87 FLYWHEEL (w/auto trans)    14085471       N.L.
1988    FLYWHEEL (w/manual trans)  14089201    $167.00
1988    FLYWHEEL (w/auto trans)    14100554     $74.75 

From: Scott Backer

Ok, it seems that Fiero 2.8-liter V-6's switched from externally balanced crankshafts to internal in mid to late 87 (not right at 88). That includes an improved oil pan & gasket, and timing chain cover. There are only two different flywheels - one for external and one for internal balancing.

From: Dave Nelson


1988 cranks internally balanced on GEN II and Rear Wheel Drive only. The piston weights also dropped by 90grams on all motors and are lathe turned. Multec injectors replace Pintle types.

From: Curt Martin


3.1L introduced, stroke increased by 8mm, piston height decreased by 4mm, dished pistons used on all motors to eliminate need for different piston sizes during service. That explains why the photo's of PISA's 3.1L kit shows dished pistons.

From: Curt Martin

"Why can I only use regular 3.1 pistons with only aluminum heads and not my iron heads?"

Aluminum heads have a 28cc combustion chamber. Cast iron heads are almost twice that. Because of that and the difference in the shape of the chambers heads from an "Generation II" engine have to be used with the "Generation II" pistons. Also because the aluminum heads have "splayed" valves (valves are not perpendicular the the head gasket surface), they will hit a piston used with cast iron heads.

From: Scott Backer

"I'm looking for info about 3.1 stroker kit for 2.8 V6 MPFI 9 code engine. Can a crank from 3.1 fit the 2.8 if so what engine and year/car, are the 3.1 rods utilized with aftermarket pistons or are the stock pistons from 3.1 used with modified rods."

1985 and later 60 degree V6's (2.8 and 3.1) have 2.648" (67.25) mains. So the 3.1L crank will fit the 2.8L block. The 3.1L crank will have to be balanced for the 2.8L. 3.1L crank from GM mini-van, Camaros, and Firebirds (981 casting) are supposed to be the ones to use because of their strength. 2.8L and 3.1L rods are the same. The difference in stroke is made up for with the pistons. The longer stroke of the 3.1L requires a shorter compression height (the distance between the center of the wrist pin to the top of the piston) than 2.8L. 3.1L pistons from a aluminum head engine can not be used with cast iron heads. 3.1L pistons from an engine with cast iron heads would work in a 2.8L block.

From: Scott Backer


1989 - 3.1L Turbo

During the 1989 model year, Pontiac sold a limited-edition version of the Grand Prix with a McLaren turbocharged 3.1L engine. Only 2000 were made, but in 1990 it became a regular production model. Power output was rated at 205hp.

From: Sketch

I saw one of these at used car lot. They wanted a 50% premium for it. It was an after market deal like a Saleen Mustang. The turbo installation was real clean. The turbo was over the bell housing. I bet if you could find one of those engines it would fit nicely in a Fiero. Good Luck in finding one.

From: Joe Boucher

1991 - 3.4L Twin Dual Cam

[Twin Dual Cam in a Fiero engine compartment]

There is a variant of the 60-degree V6, introduced in the 1991 Chevy Lumina Z34, Pontiac Grand Prix, and Olds Cutlass Supreme. It is a Dual Overhead Cam version, with aluminum heads, and possibly aluminum block as well. When first introduced, it was rated at 200 or 210 hp, but more recent versions are rated at 215hp. Quite an improvement over the 180hp of the standard iron block and head 3.4L V6. (Although this engine was introduced before the standard 3.4)

From: Sketch

1993 - 3.4L V6

"I am thinking about changing the displacement to 3.4 liters. Are there pistons available for the iron heads that can accomplish this?"
There is a new GM motor that has this displacement. However, you will need to replace your crank and pistons. Your biggest problem is that the pistons will likely be too large for the 2.8 block. To go to 3.4 you will need a new block, crank and pistons. Suddenly, a bored out 2.8 with a 3.1 crank will save you a lot of money. You will give up very little displacement. The 2.8, with a .030 over bore and a 3.1 crank will be just over 3.2L. That's easily within 5% of a 3.4L motor.

From: Lee Brown

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