Suggested swap for a fiero

[sdad]

I have a 1988 Fiero w/2.8 cast iron block pushrod and getrag manual 5-spd. For those who don't know, this is a transverse arrangement, essentially a front wheel drive, just moved to the rear. I'd like to do an engine swap, looking for a newer larger displacement that the getrag will bolt up to without an adapter plate. I would like to stay with a v-6, not the v8 Cadillac swap that many do. Going to an auto transmission is an acceptable option as long as I stay with a transverse setup. From a labor/mat'l standpoint the getrag makes the most sense, however. I am also willing to modify frame/body to accommodate.

I currently have a Ford Duratec available, but the GM seems so less profane. I just don't know squat about them!

[SappySE107]

id guess most of us know what a fiero is and has:P A billion people will say 3500 swap, because its the latest and greatest thing everyone does. If you want to leave it alone, then that is a great choice. If you want to modify and get crazy, use a 3400 block instead. It is easier and has a lot more options for bottom end upgrades.

[Superdave]

3400 or 3500 are great options, 3400 being easier and a little cheaper.

[sdad]

Thanks for the responses. Appreciate. I'll look into both the 3400 and the 3500, see what entices me.

Will I be able to locate stock HP/torque curves for these engines? Will my getrag fit onto a 3600 without an adapter?

[SappySE107]

Your trans will bolt right up to the 3400 and 3500. The 3.6 DOHC is different. 3400 made 185 max in stock form, the 3500 made 201.

[Mars]

I have a 3400 in mine and it's a real hoot. Should have come with that engine. (had it existed).

I also put in a large cam and 4 puc clutch, super fun.

[sdad]

Regarding the 3400, I found this in Wikipedia:

LA1

The LA1 3400 ("E-code") was a bored-out version of the 3100. It retained the OHV layout of the previous engine, and was first utilized on the 1996 U platform minivans. Output for the 3400 is 180 hp (134 kW) and 205 lb·ft (278 N·m).

Applications:

1996 Chevrolet Lumina APV
1997-2005 Chevrolet Venture
1996-2004 Oldsmobile Silhouette
1996-1998 Pontiac Trans Sport
1999-2005 Pontiac Montana
1999-2005 Oldsmobile Alero
1999-2005 Pontiac Grand Am
2000-2005 Chevrolet Impala
2000-2005 Chevrolet Monte Carlo
2001-2005 Pontiac Aztek
2002-2005 Buick Rendezvous

LNJ

The 3.4 L LNJ is a 204-cubic-inch (3,350 cc) modified version of the normal 3400 engine. It includes a modified intake manifold, oil pan, engine cover, and fuel system as well as electronic throttle control. It is built in China and imported to Canada for use in the Chevrolet Equinox and Pontiac Torrent. The LNJ makes 185 hp (138 kW) and 210 lb·ft (285 N·m).[3]

It appears that the LA1 will be the easier to come up with, but will the extra hassle/cost(?) for the LNJ be worth while? This is making the assumption that the DOHC engine is not the one I'm looking for.

3.5
LX9

The LX9 3500 is an OHV engine based on the 3400 V6. It incorporates electronic throttle control. Bore is 94 mm (3.7 in), stroke is 84 mm (3.3 in) for a displacement of 3498 cc (213 cu in). A GM Press Release for the 2004 Malibu described the 3500 thus: "3.5-liter V-6, will debut in the 2004 Chevrolet Malibu. The engine offers improved performance and fuel efficiency, and runs smoother and quieter than earlier generation V-6 engines. The 3500 V-6 features an advanced powertrain control module, improved fuel injection system, a redesigned exhaust manifold and a new catalytic converter contribute to reduced emissions, as well as improved efficiency and performance characteristics. Improvements in cooling, sealing and the accessory drive system add to the engine's overall quality, reliability and durability." Power output ranges from 196 hp (146 kW) to 201 hp (150 kW), torque ranges from 213 lb·ft (289 N·m) to 221 lb·ft (300 N·m).

It was used in the following vehicles and model years:

2005–2006 Buick Terraza/Chevrolet Uplander/Pontiac Montana/Saturn Relay
2004–2006 Chevrolet Malibu/Chevrolet Malibu Maxx
2005–2006 Pontiac G6 Sedan / Coupe
2006–2007 Buick Rendezvous
2006 Pontiac G6 GT Convertible

LZ4

The LZ4 3500 is an OHV engine based on the 3.9 L LZ9 V6. It was introduced for the 2006 model year in the Chevrolet Impala and Monte Carlo. It includes continuously variable cam timing (fixed overlap). It has a cast iron block and aluminum heads. Output is 211 hp (156.5 kW) at 5800 rpm and 214 lb·ft (290 N·m) at 4000 rpm. Bore is 99 mm (3.9 in), stroke is 76 mm (3.0 in) for a displacement of 3510 cc. Horsepower rating changed for the 2007 model year to 224 hp (167 kW) at 5800 rpm and 220 lb·ft (298 N·m) torque at 4000 rpm. The Chevrolet Malibu, Pontiac G6, and Saturn Aura became equipped with this engine for 2007 (previously the Malibu and G6 had the non-VVT 201 hp (150 kW) 3.5 L LX9). In 2008 SAE ratings dropped the horsepower ratings to 219, keeping torque as is. On Pontiac G6 convertible models, horsepower was rated at 217.

Applications:

2006–2009 Chevrolet Impala
2006–2007 Chevrolet Monte Carlo
2007–2010 Chevrolet Malibu/Chevrolet Malibu Maxx
2007–2009 Saturn Aura
2007–2009 Pontiac G6
2008–2009 Saturn Vue XE AWD (222 hp/220 lb-ft)

Note: GM often refers to this engine in its literature as a "3.5L V6 with Variable Valve Timing".

3.9

Bore is increased to 99 mm (3.9 in) and stroke is increased to 84 mm (3.3 in) for a displacement of 3880 cc (237 cu in).
LZ9

The new LZ9 3900 features Variable Cam Timing, a new feature on a pushrod engine, roller rocker arms and has a variable length intake manifold. The dual intake runners (One short, one longer) improves intake efficiency across a broader RPM range.

It produces 240 hp (179 kW) and 240 lb·ft (325 N·m) torque, with a wide torque curve. 90% of the torque is available from 1500 rpm to 5500 rpm. Applications:

2006 Pontiac G6 GTP Sedan / Coupe / Convertible
2007 Pontiac G6 GT Sport Package Sedan / Coupe
2007–2009 Pontiac G6 GT Sport Package Convertible
2006–2007 Chevrolet Malibu SS
2006-2011 Chevrolet Impala/Monte Carlo
2006–2009 Buick Terraza/Chevrolet Uplander/Pontiac Montana/Saturn Relay
2009–2011 Buick Lucerne

Regarding the 3500, I see 2 basic variants, the LX9 and the LZ4. Do both have the same tranny bolt pattern? If so, should I consider the LZ9, the 3900?

[robertisaar]

the LNJ is nothing special and in fact i would avoid it. IIRC, they used an oddball crank trigger setup along with other odd parts.

EDIT: and yes, both 3.5s have the same bellhousing pattern

[sdad]

Thanks for the tips. So, OK, if the LZ4 will bolt up to my getrag, that suggests that the LZ9 will as well. Correct assumption? Any down side to the 3900?

[robertisaar]

the 3.9s also have the same bellhousing pattern.

i'll let someone who has actually played with one go on about the upsides and downsides to it. IMHO, if i had to choose between a 3.5 and 3.9, i'd go 3.9.

[sdad]

Thanks, this is becoming rather interesting

[Superdave]

while the gen 4 engines will bolt to your trans there are a significant amount of other things that you'll have to deal with. 3900 in a Fiero has been done but sticking with a gen 3 engine like a 3400 will be much easier on your wallet.


There are quite a few performance upgrades for the 3400 that will help a lot. Jbody guys have pushed 3400/5 speed cars into the 11's on fairly mild builds

[sdad]

My goal with this upgrade is not a drag car, though, in reality, that's exactly what I will get (quickest et). What I am aiming for is to get the most power to the pavement through all the gears, as well as best traction through a turn, with the least weight on the wheels. This means controlling the amount of power, biggest not necessarily the best. Less weight, less traction, less needed motor. Gearing selection is also critical, as is suspension design. What really peaked my interest with the 3900 is the 6 speed tranny that bolts on. It is giving my computer one additional option for gearing. The 3900 also gives me an additional 100hp and that is in stock form. That implies reliability. My next step is to determine what I actually need to have in the way of hp/torque and then find a combination of weight/motor/trans/rearend/tire dia that will best fit.

[neophile_17]

If you're looking for a project the 3900 is very interesting. If you're looking to get the engine swapped in and driving quickly I'd advise a 3400. The 3500 is another good option with a little more cost and tuning required. Either way moving the battery to the front in conjunction with weight loss from an Al headed engine does wonderful things to balance a Fiero.

I was looking to do a 4th gen swap this summer but will end up with a second 3400 due to time and money. Many of the 3900 swap inquiries result in people going another route. A big part of this is VVT that must be either disabled, tweaked to run a binary mode, or a large portion of the donor's electrical system must be transplanted.

Many people don't like the 6-speeds ratios. Investigate the F23 if this might be a concern for you. I love my 4-speed.

My "bent" is road race oriented, so you can decide how well that fits with your goals.

~sam

[sdad]

Moving the harness from donor to Fiero is perhaps tedious but not overwhelming. I'm an EE so I am comfortable with car electronics and how to interface. Regarding the ratios on the transmissions, the computer can help determine the +/-'s of the 4,5 or 6 speeds. If we lived in a world where gas prices weren't a concern, I'd limit top speed to about 100mph ( this is a street machine) via the rear end ratio and dial back on engine size. Unfortunately.... Again, the 3400 may be all that I'd need, I do know that the 2.8 I have isn't enough. I'm not in a position yet to say what I'm going to need to just start smoking the tires, nor have I decided how many gears up that I want to do that.