2.8 vs 3.4

[GTRS Fiero]

Is there really a noticeable difference between these two push-rod engines?  Performance, economy, etc?

[Fierofool]

Most definitely.  The extra 20 rated hp is very noticeable.  Much more torque, too.  You can run in 5th gear at lower speeds and steeper hills than with the 2.8.  Fuel mileage is about the same to maybe a little better with the 3.4.  Best I ever got on my 3.4 was 31 mpg.  I never achieved that but in 1 of the 6 2.8's I've owned.  I got 33 mpg on a trip to and from The Fiero Factory but it had a huge pair of 78 series tires on the rear.  The engine is much smoother than the early 2.8.  I don't know how that compares to the 88 with both being internally balanced. 

[Raydar]

My "stock" (rebuilt) 3.4 felt like the engine the Fiero should have had, to begin with. 20 extra HP was nice, but as Charlie posted, the real difference was the torque.
After I took it back apart and built it up, it was nearly as quick as my 4.9. (In retrospect, probably not worth the money, unless you just want it to remain stock appearing, which mine didn't, anyway.)

Yeah. Big difference.

[GTRS Fiero]

Somewhere I read that a Fiero with the 3.4 still wasn't faster than his wife's minivan.  I'm guessing he meant in a straight line.

[f85gtron]

Tuning a rig has a lot to do with it. Some guys just do a straight swap and let it ride, chances are, those are the ones with meh performance results. If you tune these up, They can really scream!

[GTRS Fiero]

Well, many of the posts I've read would seem to indicate a good tune (Oreif, LostNotForgotten, lou_dais, etc), but they weren't happy with the results.  I don't remember about Dennis LaGruia.

I thought even Raydar said he wouldn't do it again.

I'm really good on the complaining side (I can find a problem) but not so good on the fix side.  Virtually any problem a car may have, I can find it.

[Fierofool]

I did a straight swap on mine, with only an injector change to the BMW injectors.  I'm very happy with it and I think it performs very well.  Less than $1000 for the engine, flywheel, gaskets, injectors and install.  It was a dropout engine and nothing had to be done to it.  Building a 2.8, 3.1 or 3.4 does cost money.  You can get as much into one to get up near 200 hp as you can by just dropping in a 3800NA, starting at over 200hp.  Not speaking for Raydar, but I suspect that's what he was getting at. 

Now, as for finding problems.  I have difficulty finding them, but they always seem to find me. 

[GTRS Fiero]

Yeah, problems find me, for sure.

(On another car) got a leak from my oil pan.  Took it apart to replace the gasket.  While it was out, saw that the timing cover is leaking, also.  Took off water pump to replace that.  While the water pump is off, replacing it, which necessitates replacing the thermostat housing, and gives me a new thermostat.  While things are apart, dropped the transmission to replace the rear main seal.  New plugs and wires while I'm in there, and of course fluids flush.  I had originally just intended to replace the shocks.  Note that this is an '03 with 254K on it, and mostly original.  While the timing cover was off, looked at the timing chain.  Add that to the list.  I think I've got $1,000 in parts.

Can't really complain.  It's been a good vehicle.

My current Fiero has been solid.  My biggest issue with it is a lack of seating.  Half of my family won't fit.

Oddly, its 0-60 is the same as the new Volt, but the Volt sure feels slower.  What is the wording?  The Volt manages 0-60 in 7.8s?  I entered the turn lane, put my foot on the floor, went up the ramp, and tried to merge with 60MPH traffic, and the car still wasn't up to 60, and I overran the merge lane.  I've never had my Fiero fail to make 60 on a ramp.

[Raydar]

...Building a 2.8, 3.1 or 3.4 does cost money.  You can get as much into one to get up near 200 hp as you can by just dropping in a 3800NA, starting at over 200hp.  Not speaking for Raydar, but I suspect that's what he was getting at. 

You nailed it. The real killer was that I started with a Grooms rebuild, since I wasn't comfortable starting out with a "pullout" and rebuilding it (or NOT rebuilding it, as the case may be.)
It was nice, but all it did was make me want more. (That's the "first rule", after all... "If 'more' is enough, then 'too much' is just right." Right?)
Anyway, I took it back apart, sold the stock heads (with 1.6 rockers that I had added) and sent a spare set of heads to be "worked". I also bought a ported lower intake from Darrell Morse, to complement the worked heads. I don't remember what the porting on the lower cost, but I had $800 in just the heads, including porting, valve job, and installation of my springs. I added a bored out throttle body, Trueleo intake, a Crane 272 cam, 19lb Bosch injectors, and FOCOA headers.
The engine ran very well. It would outright scream, for what it was. It had enough power to absolutely shatter a Getrag differential. (I also swapped the Getrag for the automatic, while I had it apart.) It really seemed as strong, although not quite as "torquey", as my 4.9.

I forget what the financial tally was when I was done, but it was stunning.
I could have easily bought a 3800SC (which the yards were pretty much full of, because they usually outlasted the cars they are installed in) and all the swap pieces, for what I had in my 3.4. And I would have started out with more horsepower, right out of the box, than I could have ever achieved with the 3.4, short of hanging a turbo on it, which I don't have the expertise to do.
And since the 3800 has a huge aftermarket, stupid power is available with bolt-ons. (Pulleys, rockers, etc.)

With that said, I am contemplating a 3.4 DOHC for the "ghost in the machine". Simply because it will pretty much bolt in using stock Fiero brackets, I feel comfortable doing the harness and ECM, and I have a line on an inexpensive one, with a crapload of spare parts.
(The DOHC is reputed to be a lovely motor for a manual trans. A 3800 SC, not so much. But that's a whole 'nother topic.) 

[GTRS Fiero]

What's wrong with rebuilding a pullout?

While we're at it, what was wrong with the 1.6 rockers?  My understanding was that the 1.52 rockers, with the 260 cam were the safer way to go, but I guess with a rework of the heads...

I'm also curious if the 3.4 is as reliable as the 2.8.

[f85gtron]

A 260 cam with 1:6 rockers will yield a 272 cameffect. The plus side is that if you go turbo, you can switch back to 1:5.
3.4 May be more reliable than the 2.8 because of better oil galleys and block webbing.....supposedly.

[Raydar]

What's wrong with rebuilding a pullout?

Nothing, if you possess the necessary tools and (especially) skills. I had neither.

While we're at it, what was wrong with the 1.6 rockers.  My understanding was that the 1.52 rockers, with the 260 cam were the safer way to go, but I guess with a rework of the heads...

I'm also curious if the 3.4 is as reliable as the 2.8.

Since I already was redoing everything, I just decided to install the cam that I wanted, instead of using a "smaller" cam and then using the 1.6 rockers to augment it. Just made sense to me to do it that way. (A turbo was never a consideration. Don't much care for them. Just a personal preference.)
 
Aside from that, I had read numerous stories about people wiping out brand new Crane cams, in the first 500-1000 miles. Figured the 1.6 rockers wouldn't help that situation any.

[GTRS Fiero]

How about just a stock 3.4?  Anyone done that?  How would that compare to a 2.8?

Even with porting the intake and exhaust, and using a bored throttle body, it would seem that, if you changed the stock cam to a 272 and bored out the 3.4, that the power would move to the upper RPM range, where the larger engine would have a breathing problem.  Perhaps not with the Truelo intake, though.

[GTRS Fiero]

While we're at it, which is better: rebuild or remanufactured?

If you bore an engine, say .060, doesn't that compromise the block?

[Raydar]

How about just a stock 3.4?  Anyone done that?  How would that compare to a 2.8?

Even with porting the intake and exhaust, and using a bored throttle body, it would seem that, if you changed the stock cam to a 272 and bored out the 3.4, that the power would move to the upper RPM range, where the larger engine would have a breathing problem.  Perhaps not with the Truelo intake, though.

My "stock" (rebuilt) 3.4 felt like the engine the Fiero should have had, to begin with. 20 extra HP was nice, but as Charlie posted, the real difference was the torque.

Everything conspires to choke the 3.4, when it's dressed up like a 2.8. The upper intake is "just enough" for a 2.8, but it really strangles the 3.4 on the top end.
Al of that head work, cam,  and headers are great, up until 4500 or 5K, and then it's essentially all done.
Either a Trueleo or "Dawgs modified" stock intake will work in concert with all the other mods.

My 3.4 engine was a "Grooms re-man". It's the identical engine that the Fiero Factory was using in all their swaps. I purchased it through Ed, and installed it myself.
In my context, I use "rebuilt" and "re-man" interchangeably, although some would argue that there is a difference.
For what it's worth, before mine was even broken in, it blew a head gasket, due to a broken head bolt. (I dollied the car to Ed, and Grooms paid him to R'n'R the engine so that they could "re-rebuild" it.)   
There were also some oil consumption problems with the GM 3.4 crate engines that used to be available. GM refused to warranty them, because they were designed as a replacement for the 2.8 in an S10. They argued that it was an "improper application", and basically told the Fiero folks to stuff it.
So, anything you do can be a crapshoot, no matter how much you spend, up front.

Boring a 2.8 to a 3.4 *can* compromise the block. ARI does it that way, but they test each block that they bore, to make sure the walls are not compromised. It really depends upon the individual casting. Even if it doesn't, there's no room left to rebuild it beyond a 3.4. (Factory 3.4s start out with a thicker casting, so that's not a problem.)
I'm not sure what the limit on overboring any particular engine is. It depends upon each individual engine, as much as anything.
My brother, back in the day, rebuilt a 265 Chevy into a 283. There was some concern regarding the cylinder wall thickness. I was only about 5, so I don't remember much of anything beyond that.   

Link to ARI... http://www.engine-parts.com/GMV6/gm28stroker.html
Edit - Lots of dead links on that page. They may be out of business.