Actual differences between the '86 and '87 LC2?

[Raven]

Help me set the record straight regarding the EXACT differences (mechanically only) between the 1986 and the 1987 LC2 motors.

I am not aware of any actual mechanical differences between the two years but I have never owned an '86 - only '87's (four of them). I've always read the HP/Torque numbers were raised for the '87 due to GM's raising the Vette's numbers and that essentially, the engines for both years were identical (other than rod bolts and possibly the rods for '87 and even that is unverified).

IF there are any actual differences mechanically in the drivetrain for the two years, what are they in detail?

Anyone?

 

[Phoff]

Pistons are different......

 

[d0n_3d]

huh??? no they are identical down to every nut and bolt...the horsepower difference may have came from the updated chip programming but that is it

 

[dgreen1069]

huh??? no they are identical down to every nut and bolt...the horsepower difference may have came from the updated chip programming but that is it

He's right....the only difference is a minor tweak in the PCM chip.

 

[Phoff]

There were alot of changes...mostly small...the pistons are different...the 1987 pistons were heavier than the 86 cars.....every nut and bolt is not the same....

Pete

 

[Phoff]

The cars made the same horsepower in 1986 and 1987....Buick changed the horsepower and torque rating because the Corvette did....the chips in the 1986 and 1987 cars were changes several times during the two year period because of cold start problems and driveability issues not to add power...

Pete