I'm not planning on starting this for a few more months, but I am thinking of rebuilding my 87 V6, cause I have no idea what shape it's in, and would like a little more power :-)

Now, should I just rebuild it as a 2.8? Or go all the way for a 3.4? I don't want to go for a V8, btw. I also want to avoid having to put in a new computer (though putting in a custom chip, or some other method of reprograming the fuel curve is fine), so for the most part I want to stick with this engine type.

So what are the merits of each size? What are the drawbacks (if any) of the 3.4? And what (aprox.) is the cost? (and that's without using any of the more exotic parts, I'm not gonna be racing on the track, just the streets ;-) ).

Thanks for your comments.

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87 GT V6 Fiero

I think the 3.4 GM crate motor is what you want. Its around $1800 plus; need 88 or 3.4 flywheel if going in manual trans; block ground away if going in auto trans; starter holes drilled; clearance hole drilled; mount for ac bracket; maybe 3.4 injectors; brass adapter fitting for oil sensor; water pump; adjustible fuel regulator; timing mark on harmonic balancer; I'd get all new sensors; parts transferred from 2.8 to 3.4 and your ready to drop it back in. $2600 to $3000

Most fellows are stroking the 2.8L to a 3.1L - involves crankshaft and pistons for a 3.1L and depending on which one you are starting with a few other parts. BUT an idea to consider is building a 3.4L and bore it .030" over and using a 2.8L crank(1988) and pistons(oversized) to match the bore size.

Something to think about...

Its like asking what is the best car out there. Everyones opinion is different.

I had a 3.4 crate installed in my 88 after the reman 3.1 failed. The original 2.8 had 5 cylinders.

My stock 87 works fine and if I wanted to keep the car completely stock, I wouldn't hesitate to rebuild it as stock 2.8.

If you are doing the rebuild and want additional power the 3.1 is pretty straight forward while a rebuild to a 3.4 may be a little more work. If you are going for an engine replacement, you can't beat the 3.4 and have it look just like a stock 2.8. Let your pocket be your guide.

3.1L 175 hp V6
2000 lumina
Horsepower 175 @ 5200 RPM
Torque (lb-ft) 195 @ 4000 RPM
Displacement (cc) 3136
Turbo/Supercharger No
Bore X Stroke (in.) 3.5 X 3.31
Compression Ratio 9.6

3.4L 160 hp V6
1995 camaro
Horsepower 160
Torque (lb-ft) 200
Displacement (cc) 3392
Turbo/Supercharger No
Bore X Stroke (in.) 3.62 X 3.31
Compression Ratio 9

Why is the 3.1 more horse and almost more torque? better yet what can be done to the 3.4? The only difference that I see it the compression. and .6 isn't that much. better yet can you stroke the newer 3.1 (those number are out of a '00 lumina) to 3.4 and get closer to 185/210? Next how much would you lose on the 3.1 by putting the Fiero heads on it?

Oh and I think going .030 over would miss the 3.4 mark bore on a fiero is 2.99 vs 3.62 you would have to bore it .63 over, and I'm thinking that is a little much, the stroke is within .01 tho.

[This message has been edited by RacinRob (edited 04-17-2002).]

Those engines are two completly different engines. The 3.1 from the lumina is an aluminum head motor and the camero is an iron head like the fiero motor.

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JOEJOE Aol:SSFiero
Two 88FORMULAS Red & Yellow and a Black 86GT
SSFiero@Aol.com

quote Originally posted by RacinRob: Why is the 3.1 more horse and almost more torque?

The aluminum heads on the 3.1 flow a lot better than the iron heads on the Fiero and the Camaro 3.4.

quote Oh and I think going .030 over would miss the 3.4 mark bore on a fiero is 2.99 vs 3.62 you would have to bore it .63 over, and I'm thinking that is a little much, the stroke is within .01 tho.

I think you have the bore and stroke mixed up. The bore on the Fiero is 89mm (3.50") and the stroke is 76mm (2.99")

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Doug Chase
Duvall, WA
'88 Fiero Formula 5-spd (autocrosser)
'88 Fiero GT 5-spd (daily driver)
'85 Fiero GT 4-spd (rally car)
'86 Fiero GT 5-spd (organ doner for rally car)
'86 Fiero GT 4-spd (fixer-upper, 4 sale soon)

oops my bad.

ok, what happens if you cross the 3.1 heads and a 3.4 block? yes I know you can't swap on the fiero stuff.

[This message has been edited by RacinRob (edited 04-17-2002).]

Okay, what if I was to go with a 3.4 Camaro engine instead of turning the 2.8 to a 3.4? Right now it's starting to look like boring over to 3.4 might be a bit much for the 2.8, so I'm thinking either 3.1, or the 3.4 from the Camaro.
I've noticed we have a member selling slightly used ones out in Texas that look like a decent deal. If it's not too much of a pain to swap in maybe I should do that?
(please keep the comments coming! The more I hear the better decision I can make for what I want!)

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87 GT V6 Fiero

The most critical part of the 3.4 swap, is drilling the starter holes....Get a jig from someone....using the starter as a drill guide is crazy. And anyone who suggests using the starter to do this,....is crazy. Why?....The holes in the starter are too big to properly guide the drill, as the drill diameter is the minor diameter of the threads in these holes...it has to be right on.