Engines

[Atilla the Fun]

As I haven't yet removed the Firebird 3.1 from my Fiero, I want to ask those of you who have built more than one Fiero, with more than one non-Fiero engine: Is a 3400 SFI with aluminum heads the lightest V6? Is the 3800-2 or the DOHC the heaviest FWD V6? Is the DOHC lighter than an aluminum-headed 350? Is the 3800 lighter than the DOHC?
I'm afraid of the iron-headed 350, and the torque of a 6.0, like the LS2. I want 260 rwhp, and 26 mpg at 65 mph. My 4 most real options are an aluminum-head 350, a 3800 series 1, like late 80s, with a paxton, a DOHC with the paxton, or a truck 5.3L LS-series (LM7)
I dislike the cost and thickness of V8Archie's plate for the LS, and I feel it 's a poor fit, space-wise. I want the DOHC, and have the 350. less heads.
I'm excellent at porting heads, and have SuperFlow 1120 numbers to prove it.
And I've read dozens of opinions on here as to the real torque capacity of the transmissions, so for real, will my 4.10:1-geared '84 4-speed live behind any of these? Will an '87 Fiero Getrag? On drag radials?
Thanks! -Atilla

[Aaron]

As I haven't yet removed the Firebird 3.1 from my Fiero, I want to ask those of you who have built more than one Fiero, with more than one non-Fiero engine: Is a 3400 SFI with aluminum heads the lightest V6? Is the 3800-2 or the DOHC the heaviest FWD V6? Is the DOHC lighter than an aluminum-headed 350? Is the 3800 lighter than the DOHC?

The 3400 SFI will be pretty much the lightest, unless you are able to find an aluminum block for the 2.8, but those are very very rare. The 3800 and DOHC are pretty much equal, but beefier than the 60* OHV engines. People will argue otherwise, but I think a DOHC weighs about the same as an aluminum head SBC.

I'm afraid of the iron-headed 350, and the torque of a 6.0, like the LS2. I want 260 rwhp, and 26 mpg at 65 mph. My 4 most real options are an aluminum-head 350, a 3800 series 1, like late 80s, with a paxton, a DOHC with the paxton, or a truck 5.3L LS-series (LM7)
I dislike the cost and thickness of V8Archie's plate for the LS, and I feel it 's a poor fit, space-wise. I want the DOHC, and have the 350. less heads.
I'm excellent at porting heads, and have SuperFlow 1120 numbers to prove it.
And I've read dozens of opinions on here as to the real torque capacity of the transmissions, so for real, will my 4.10:1-geared '84 4-speed live behind any of these? Will an '87 Fiero Getrag? On drag radials?
Thanks! -Atilla

260rwhp and 26mpg is a challenge for an old school, carbed SBC. Every SBC owner claims 35mpg, but in reality, there's no way any of them are seeing over 25, at least not tuned properly they aren't.

You don't want the SBC. The cost is significantly more than any other engine swap, and the swap is much harder.

I would honestly point you towards the 3800-2. 260rwhp is easy, and 26mpg won't be a challenge either. And although the engine isn't cheap, nor are the mods for 260hp, the swap isn't very expensive or too difficult.

The DOHC will require forced induction to plausibly hit 260whp. Paxtons suck. So you're pretty much left with a turbocharger. And if your goals are only 260, then dropping 2-3 grand on a turbo kit isn't economical.

[lucky]

easy to find 2.8 aluminum block, just way out of most fiero owners price range.
http://store.summitracing.com/egnsearch ... ults=false

[Aaron]

4 grand for a bare block? Yah fucking right. That's in my price range, but still a complete ripoff. However, I recant my statement as them being rare. Reasonably priced blocks are rare :thumbleft:

[Atilla the Fun]

Aaron, are you thinking the non-supercharged 3800-2 can get to 260? How? I already have the Paxton (used). If I'm not mistaken, you have a DOHC Fiero, right? Thank you for the input! -Atilla

[Aaron]

Aaron, are you thinking the non-supercharged 3800-2 can get to 260? How? I already have the Paxton (used). If I'm not mistaken, you have a DOHC Fiero, right? Thank you for the input! -Atilla

The amount of work it'd take to get a N/A 3800 to 260whp would make for a very expensive project, and much more work and money than a 3800 SC. It can get there, but not without much more work than its worth. You basically need to gain 100hp, and with such a poorly engineered engine (For performance), you basically have to fix every component relating to performance ($$$).

I mean, you can use the Paxton, and you can get 300whp without a problem on either platform with it, but I just don't like CF superchargers....at all. The reason I said go with the 3800 is because it really is easy. On the DOHC, you will get more, and it will be a better driving and performing engine, and I think you'd be happier with it, but it requires a lot of time and custom work, especially for just 260whp. With the same amount of time and custom work it takes to get you to 260 on a DOHC, I'll be breaking 400 without a sweat. You'll need everything I've done, and everything custom done because there is no aftermarket. And that's a lot of work for just 260hp, an easily attained goal with a bolt on 3800.

I have 2 DOHC Fieros. Well, I built one then sold it to a friend, but I still work on it, drive it, etc whenever I want (It's at my house as we speak lol). The other in my sig is still being built. It has been running and driving without the turbo, and now I'm adding the turbo. See my build thread here, the actual build doesn't start until Page 2:

http://www.thefuseforums.com/viewtopic.php?t=103

And here is the long build thread for my first DOHC Fiero (Build also starts on Pg 2). It is a mostly stock engine, so figure ~220chp. But this summer it gets a brand new crate engine, 96 intakes, 13* retard, 75mm throttle body, and some other toys.

phpBB/viewtopic.php?t=3484&highlight=build

[Blue Shift]

Lightest engine you mentioned will be 3400. Add some mild boost and you're done. Should do the job.

For 260 HP and ultimate lightness, the turbo DI ecotec will give you exactly 260 HP, really light weight, and exceed your mileage requirements.

Carb SBC and fuel mileage do not go in the same sentence, unless you install an RV cam and a 1 or 2 barrel carb. Then you'll fall short of your HP requirements.

If you need 8 cylinders and don't need super lightness, you ever think of the LS4 DoD 5.3 FWD engine? No crappy adaptor plate needed, 300HP, 30 MPG.

[Edit]: Note that I built and daily drive a California legal 3.4L DOHC, and didn't mention it. It'll get the mileage you want when stock, but it won't make the HP without boost, and it's also heavy. It could be done, but it's more of a stretch to achieve your goals.

[crzyone]

The quad 4 is fairly well documented as well. Nice and light, probably the same weight as an iron duke. You would only need mild boost to make 260hp, they make around 190hp from the H.O. version.

Bryson built a 400whp quad 4 fiero but it suffered a failure from a broken ARP rod bolt. Not a very likely failure, was too bad. One of the baddest fieros built at that point.

All the V-6s are going to be fairly heavy compared to a quad 4 or ecotec. If I were to start over I would use an ecotec with a turbo. Light weight and powerful. I could care less about the V-8 sound.

Last thing you want is a cast iron boat anchor like the 3800sc. It makes good power but is not really suited for a fiero. Never been a fan. Unless you are using the auto trani and want to build it for serious power, stick to a 4 cylinder. You will get the mileage you are looking for and the power with a turbo.

A Garrett GT2860R 707160-7 is rated to 310hp. That would give you 260whp easily and you would have great response and minimal turbo lag. There are many turbos to choose from, depends on how you want it to drive.

[Fiero_insurgent]

The 2.2 Ecotec with supercharger from the Cobalt should be close to your goals. I think it may be a little short on HP though, but you can change the S/C pulley to compensate for that...

[lucky]

not to hijack or anything, but while talking sc's and turbos, what's up with Fageol Performance? found their site through the 60deg forums. Roots style sc for 2.8 sounds nice, but unless anyone knows i'm gonna email them about why they have a part # for the fiero, but it's "not available".

[Aaron]

For 260 HP and ultimate lightness, the turbo DI ecotec will give you exactly 260 HP, really light weight, and exceed your mileage requirements.

I didn't even think about this, but damn that'd be the engine to have! If you can past the initial cost, and the wiring hell, that would make for a kickass motor. And you'd have 260whp with just the swap, I mean a nice 3" exhaust, CAI, maybe a pound or 2 more, and you'll be there.

The 2.2 Ecotec with supercharger from the Cobalt should be close to your goals. I think it may be a little short on HP though, but you can change the S/C pulley to compensate for that...

It'd take a lot to recover the 60whp it's short by, and that blower isn't exactly good for making more boost than it already is. I'd stick with the Sky/Solstice motor.

not to hijack or anything, but while talking sc's and turbos, what's up with Fageol Performance? found their site through the 60deg forums. Roots style sc for 2.8 sounds nice, but unless anyone knows i'm gonna email them about why they have a part # for the fiero, but it's "not available".

They make a roots blower for the iron head 60*s. It is a very small and inefficient blower, and IIRC only setup for carbs as of now. And the 2.8 doesn't react well even to efficient boosting, so I'd imagine the performance increase is lackluster at best.

[stimpy]

No Tech allowed! :cussing:

Attila, welcome to the forum. I like your hp goals, that is around what my sc3800s2 was doing in my 86 GT. I'm moving this thread to "Tech" so it can get some proper attetntion. This forum is for monkeys to fling their poo in.

[lucky]

not to hijack or anything, but while talking sc's and turbos, what's up with Fageol Performance? found their site through the 60deg forums. Roots style sc for 2.8 sounds nice, but unless anyone knows i'm gonna email them about why they have a part # for the fiero, but it's "not available".

They make a roots blower for the iron head 60*s. It is a very small and inefficient blower, and IIRC only setup for carbs as of now. And the 2.8 doesn't react well even to efficient boosting, so I'd imagine the performance increase is lackluster at best.

They had a part # listed for 87-88 Fiero v6 (i assume it's set up for mpi), and they claim 35% HP increase :dontknow:
i was daydreaming about this engine with a nice easy bolt on sc (i can turn a wrench but i'm not great at fabrication)

[Atilla the Fun]

wow, I missed alot being sick all week and working 45 hours anyway. As a machinist, my experience is inside the engines when they are disassembled. With a Getrag, and 26"-dia. tires, rpm at 65 mph will be approx. 2200. So, I know how to get a Camaro with a 350 to get 25 mpg hwy geared like that,and 300 flywheel HP . But I sold my 350. Second, to get 260 wheel hp up here at 4300 feet, and assuming a 40 hp loss thru the Getrag or Muncie, using synthetic fluid, that's 300 flywheel HP up here, which is 360 at sea level. Ouch! The Correction factor changes if turbocharging, from 4% to 2.5% per 1000' elev.
So, I know there are lots of aftermarket upgrades for tyhe 3800SC, and I can use pistons for the old Grand National turbo Buicks, but those heads will never flow like stock DOHC V6 heads, no matter the porting.
As for legality, the small Block Chevy isn't cost-effective around here, and I don't want to run an automatic for the 5.3. The 6.0 could be done as an LS2 from a GTO, but goodbye transaxle.
Speaking of which, I think Black Coffee should consider the T76 as the compressor half of a turbo, as it matches well with the 5.3, at 1.4 bar, and at 1.6 and 1.8. I didn't figure 2.0 since that engine seems finished, with stock pistons.

[Atilla the Fun]

Oh. I forgot. The 3400 SFI has been ruled out due to the scarcity of it with a 5-speed, and the lack of aftermarket support of any aspect not shared with the 2.8. Oh, why was this moved? I apologize for posting it in the wrong place. This is the first and only forum I have ever tried to participate in.

[Aaron]

Oh. I forgot. The 3400 SFI has been ruled out due to the scarcity of it with a 5-speed, and the lack of aftermarket support of any aspect not shared with the 2.8. Oh, why was this moved? I apologize for posting it in the wrong place. This is the first and only forum I have ever tried to participate in.

I don't think the 3400 ever was offered with a 5-speed.

Next, what does it matter? Do you need to pass CA emissions? If not, a Fiero Getrag will work perfectly fine behind a 3400.

It was moved because this thread is turning technical, and RFT vs The World is Shaun's place to bitch about SBCs. No big deal :thumbleft:

[Atilla the Fun]

worse than cali!!!! Our county just fell into non-compliance, not due to cars but due to the dang livestock. So, the EPA is writing new policy. For a normal annual inspection I can stick a 2.5L 4-cyl in it, despite the labor. But cali has roadside checks and worse. Heck, L.A. has virtually zero livestock, just cats and dogs. In our region, it's an everyday thing to commute up to 100 miles each way, every day. Please forgive my fussing. As to a boosted ecotec, I'm just not able to accept running more than 1.8 bar. Not without E85. Lastly for now, to anyone wondering about the '90 firebird accessory drive in a fiero, the passenger side is fine, you just can't use the driver side, meaning no a/c or p/s. I finally took pics with a digital camera. Now I can pull it back out of the car!

[Aaron]

That sucks, here in Colorado, they just did away with emissions testing.

The 3.4 DOHC will be slightly more difficult, but not impossible, to pass CA emissions. Series8217 and Blue Shift both have CA-BAR inspected 3.4 DOHC/5-speed Fieros.

[Series8217]

worse than cali!!!! Our county just fell into non-compliance, not due to cars but due to the dang livestock. So, the EPA is writing new policy. For a normal annual inspection I can stick a 2.5L 4-cyl in it, despite the labor. But cali has roadside checks and worse. Heck, L.A. has virtually zero livestock, just cats and dogs. In our region, it's an everyday thing to commute up to 100 miles each way, every day. Please forgive my fussing.

Where are you located?

[The Dark Side of Will]

and assuming a 40 hp loss thru the Getrag or Muncie,

Thats WAY too high. I don't think you'll get to that much parasitic loss until you're pushing significantly over 400 HP.