positives and negatives of different Engine swaps

[Dr. Sievers]

Okay so I wanted to start this thread; one because I know that this is just about everyone's favorite topic and two to help people get a little more coverage on these different options for them.

So I initially had planned, when I purchased my current fiero, to swap in a 3800sc series II, now I have been looking around and although that V6 with the blower looks oh so sexy sticking up outta that engine bay, I'm thinking maybe a different engine may be a better fit for what I'm trying to accomplish.

My goals are: Light weight is a must, positive mulitplying down-force, good fuel economy, hasty acceleration, nicely derived exhaust node (no fart cans) easy maintenance after installation.

Some of the engines I've concidered are:

3800sc series II and series III
ecotec 2.2L
3400 NA
Super Duty 4

Pros
3800sc series II: cheaper of my 3800 choices, Lighter than the 2.8L V6, mounts straight to the 5-spd getrag, clean sound, parts are common, low 200hp stock

3800sc series III: more power stock and modded than the series II, lighter than the 2.8L V6, mounts straight to 5-spd getrag, clean sound, parts are readily available, mid 200hp stock

ecotec 2.2L: best fuel economy, lightest engine, fits compartment with almost no modification, parts are cheap and readily avialable, 200hp

3400 NA: hooks straight up to everything, no modification needed, cheapest of the motors when available, 190hp stock NA

Super Duty 4: Hooks up to everything that is currently in my 85 2M4 SE, 140hp stock on average


If I have misrepresented anything please let me know so that I can correct it right away. Please add in your own information about these engines and there swapability with the fiero. Any and All info is welcome and deffinately appreciated!

 

[Oreif]

Well let me clear up some things.
The 3800 and 3800SC engines weigh MORE than a 2.8L. The 2.8L weighs around 360 lbs and the 3800 N/A is around 390 lbs and the 3800SC is around 420 lbs. They have a very large aftermarket so mods are not difficult.

The Ecotec will fit, But you need to do many mods because the transaxle bolt pattern is different. Requiring you to use the mating transaxle. This would require looking for the correct length axles. The plus side is there are turbo and superchargers for them. An engine and trans set-up from a Colbolt SS would be a good swap.

The 3400 is way different than the 3.4L. The 3400 has aluminum heads and requires wiring/PCM modifications. The 3.4L has iron heads (the same as the ones on the 2.8L) and was only used in the 1993-1995 F-body cars. The 3.4L is a nearly direct swap and yeilds 160hp. The newer engines like the 3.5L, 3.6L, 3.9L are all 60* V-6's and fit in a Fiero, But the bolt pattern is slightly different and it requires a lot of wiring. Many newer vehicle have the PCM controlling the engine and the trans so if you use an old transaxle, You needs to get creative with re-programming the PCM. It's been done before and a few places know how to do it. Another option is the 3.4 DOHC used in the early 90's. About 220hp and it is a high-revving engine. With a turbo they can see 400+ HP.

The Super Duty (SD4) is expensive to build. The engine is a race engine. A basic build like what was used in the original real 1984 Indy Pace Fiero (the ones used on the track, not the replica's sold to the public.) had 232 hp. With a cam change they put out around 270hp. With the 16-valve cosworth head they can get into the 340 hp range.
Note that these block are stamped "for off road use only" GM no longer makes them but Kansas Racing Products is licensed by GM to make them for ARCA racing. You can get a 285 hp race engine (that will bolt directly into a Fiero) for around $12,400

Some other swaps to consider:
The Cadillac 4.9L used in the mid 1980's is an aluminum engine. It weighs about 370 lbs, has 200hp and will bolt up to a Fiero transaxle. Aside from the 3.4L this is the next easiest swap to do. Many like these swaps because you have the torque of a V-8 and the unique V-8 sound without having to do many mods. It just requires you to make mounts and splice in the PCM. There are very few aftermarket parts and finding a used one in good condition can be difficult.

The Northstar is a nice engine, But weight with the large overhead cam heads it weighs nearly 460lbs. It is a tight squeeze due to the large heads, but does offer nice power.

Small Block Chevy engines (SBC's) have many options like the newer LS series engines (they weigh around 380 lbs) or even a ZZ4 with an iron block and aluminum heads (weighs around 410 lbs) to a LM1 which is 455lbs. These engines require a special kit to mate to the Fiero transaxle, a special flywheel, as well as some other unique parts. The advantage to using an SBC is the Chevy V-8's have a HUGE aftermarket so performance parts are plenty and fairly priced. GM sells crate engines so you can get a brand new engine (LS engines are lots of $$$$)

The 4.3L V-6 weighs around 390 lbs and requires the same kit as the SBC because it uses the same bolt pattern. A 4.3L is basically a Chevy 350 V-8 with 2 cylinders cut off.
Average aftermarket can give you a boost in power.

Basically any Engine from GM can (and has) been swapped into a Fiero. The thing is you need to figure out how much do you want to spend, how much power you want, and how you want the car to feel. Some examples are a SBC V-8 will make the car feel like a streetrod/classic muscle car, a 3.4 DOHC will make it feel like an exotic high revving sportscar, and a 3800SC gives you the tame daily driving car with a huge power boost making the car a "sleeper".

There is no "perfect swap" it all comes down to personal preference and how you want the car to act/feel.

 

[Dr. Sievers]

Hey Oreif, you wanna move in with me while I'm working on this car? lol...

Jebus Crisco! GM is a lot more complicated then they seem. As you know Oreif I'm coming from the japanese lines and I swear when you've been playing with one brand you get used to what they do and then I come over here and find out that the 3.4L isn't a 3400!? And, thank you for clearing up the 3800sc. I had checked them out to what I thought was thoroughly but apparently a lot of people mis-represent that engine. I had read in a few places that the series II was only around the 340lbs are not the 400+lbs area.

So tell me this Oreif, in your opinion.

I want the car to not just feel but be light.
lbs per HP in the low teens.
I want responsive.
I don't want to have to drop the cradle everytime I want to do an oil change.
sound just needs to be clean
decent fuel economy
if it looks pretty under the hood then sweet if not cosmetics don't matter

Ultimate goal is to achieve a track capable daily driver

 

[Oreif]

On engine weights, Most list "stripped" which means the basic engine like the block, heads, and intake. The weights I posted are "dressed" meaning once you add on the pulley's, Alternator, exhaust manifolds, full intake, harness, etc. We had a guy actually weigh many engines in the "ready to run" condition.
The 3800's are cast iron engines with cast iron heads. So just the bare block and heads weigh more than the 2.8L bare block and heads due to physical size. The 2.8L is a 60* V-6 and the 3800's are 90*. It also depends on what you start with. I installed a ZZ4 SBC V-8 with a 4-spd. The car originally had a 2.8L with an auto transaxle. The total weight of my car only changed by 30 lbs. (the weight removed by going from an auto to a manual was added back on going to a V-8 with aluminum heads.)

The other thing is weight doesn't have as much of an effect on a Fiero due to it's mid-engine design. Take a regular car like say a Honda Civic and run it down the 1/4 mile. Then have a 150 lbs passenger sit in the back seat and run again. You are only going to see about a .15 second difference. So yes you might add 50 to 80 lbs during a swap, But you are also increasing power by 50% or more. So while it may be a trade-off it has very little effect.

I have been into Fiero's ever since I bought my first one brand new in 1986.
I have built two 3.4L engines for Fiero's and they both had 230 hp. One was with a carb and the other was EFI. (both normally aspirated) In 2004 I did the SBC V-8 swap. I really like the "streetrod" feel with gobs of low-end torque.

For light with excellent response, mileage, and a lbs per HP ratio of 12:1, You might want to look at the 3.4 DOHC (Dual overhead cam) engine. It will make the car run about high 13 seconds in the 1/4 mile and around 5 seconds 0 to 60mph. Add on a turbo and you can get into the 11 second range and still get 30+mpg. Getting your lbs to HP into the single digits (7:1). Also it is California emisson friendly.

Here is what one looks like in a Fiero:

And here's one painted up to match the original Fiero scheme: (and a turbo!)

This link has some pics as well: http://dtcc.cz28.com/Customer/3.4DOHCFiero/index.htm

The swap is not difficult to do. The most labor involved is in the wiring. You just need to make a new front engine mount and a new dogbone mount. The trans mounts stay stock.

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[Dr. Sievers]

wow! that red is dead sexy... I love the way you have that hooked up! I think I may take your advice on this and do the 3.4L DOHC swap instead. I've been looking around and they aren't that expensive. plus from everything that I can see it all hooks up really simple. one thing though as far as transaxles go could I use the getrag or would I have to get the muncie? I like 5-spds is why. Actually I prefer 6-spds but for a car this age I'd rather have 5.


Edit: I have one more question. As far as cross swapping, have any been successfully done? Maybe a mopar turbo charged world engine or a TRD 3sgte or a Nismo 3.0TT or a cosworth 2.8L V8TT? Not asking this because I want to do this or anything, just wondered.

 

[Oreif]

Actually the Getrag is a Muncie as well. With the DOHC engine you can use the V-6 Muncie 4-spd or the Muncie/Getrag 5-spd. Most prefer using the 5-spd with the DOHC engine because of the gearing and the high RPM range of the engine. The F40 6-spd manual would be nice as well. I don't know if anyone has done a 6-spd/DOHC swap yet.

As for cross-swaps, I've seen one with a Ford 5.0 and I know of a person who used a VW VR6 engine. There was someone swapping a V-8 from a Range Rover mated to a NSX 6-spd transaxle but I never heard if he ever completed it. The problems with cross-swapping is adapting the Fiero electronics (gauges, speedo, etc.) and the different transaxle axle lengths. Many times you need custom axles made and the cost can be rather high. Some have discussed doing other swaps, But with the GM friendliness of the Fiero engine compartment, it is less expensive to find a GM engine with the power you want.

 

[Dr. Sievers]

Nice! cosworth 3.0L V10 here I come! lol j/k. However, you got to admit that would be really bad ass having an 18.5K redline and 850 ponies screaming out of that little car. However the head ache that it would cause just sitting in the car with the engine running probably would make it not worth it. Formula one you make a gorgeously painful engine.

 

[Dr. Sievers]

Hey Oreif, I have been doing some research since you recommended to go with the 3.4L DOHC and I noticed that I've read a lot more negative things than positive things about that engine. Some of the things they said about this engine is that they eat MAF and O2 sensors, it's belts go bad very quickly, they tend to blow head gaskets very easily, and that the ECM's for them have issues with the original programming and that only a handful of people have been able to overcome the programming issues. What's your take on that?

Also sorry for asking you a thousand and one questions. You seem very knowledgable and so I figure, ask the guy who probably knows, right?

Also I was reading that a lot of people recommend to do the NA 3.8L over the SC because the SC vibrates custom mounts to pieces...? Not sure why it would make a difference there but just some things I've read.




BTW the big engine do you think that'll fit LMAO! or maybe either of the other two?

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[Oreif]

Hey Oreif, I have been doing some research since you recommended to go with the 3.4L DOHC and I noticed that I've read a lot more negative things than positive things about that engine. Some of the things they said about this engine is that they eat MAF and O2 sensors, it's belts go bad very quickly, they tend to blow head gaskets very easily, and that the ECM's for them have issues with the original programming and that only a handful of people have been able to overcome the programming issues. What's your take on that?

Also sorry for asking you a thousand and one questions. You seem very knowledgable and so I figure, ask the guy who probably knows, right?

I have never heard of them eating MAF's or O2's. The belts require proper maintenace and need to be changed every 50K miles. Many don't do that or even change to new belts when they do the swap. The 1991-1993 engines did have an issue with head gaskets. GM has a TSB on changing to a better designed gasket. The newer gaskets were used on the 1994-1997 engines so the later engines do not have the problem. You can find the newer engines in:
1995-1997 Chevrolet Monte Carlo Z34
1995-1997 Chevrolet Lumina LS
1997 Chevrolet Lumina LTZ

As for programming, Ryan at Sinister Performance ( www.gmtuners.com ) has done numerous 3.4DOHC swaps You can see them on his website. He can assist you with re-programming as well as specifics on installing the swap. Basically he would have you take a reading off your PCM, Email it to him, He then mods it as needed and Emails the new file back and he explains how to flash the PCM so you can upload the new file and you are done.

Also I was reading that a lot of people recommend to do the NA 3.8L over the SC because the SC vibrates custom mounts to pieces...? Not sure why it would make a difference there but just some things I've read.

I have never heard of 3800SC's causing mount problems. The 3800SC is a very, very popular swap. I know many personally who have stock and highly modified 3800SC's and they have never had an issue with the mounts. Some have had their swaps done since the late 1990's. Were these mount issues from 3800's in a Fiero? Do you know if they were from a particular vendor who supplied the mounts? There are a few places making mounts for 3800SC's.


As for the big engine, A sawzall can make just about anything fit.

 

[Dr. Sievers]

they didn't specify on the 3800sc, but, then again I ask because I know how much stuff on the internet is completely off key.

As for the 3.4L yeah that makes a lot of since with what you said cause when you read them a lot of people where talking about the older generation. And I read the O2 and MAF sensor only in two places so I'm just going to assume it was one persons problem and everyone just jumped on the bashing band wagon.

And:

BIG ENGINE MMMMMMMMM... lmao. although funny as hell i don't think I'd ever want to drive a jet engined car. no cornering capabilities.

 

[adelsin]

As far as the 3.4 DOHC, this is also my conversion of choice. However, I am having a very hard time finding crate engines, or even used engines. Don't the 5-speed Fiero Gearboxes work well with the DOHC versus the 3800S/C? What has a faster 1/4 mile time with both being stock?

I also found a place based in Dallas, fastfieros.com that focuses on 3800S/C conversions. I currently have an email out to him as well.

I suppose I should first find a Fiero to start modifying. Problem is, I'm currently deployed. Would love to just fly in, pick one up (already modified) and drive home.

 

[J Wikoff]

Cobalt SS supercharged or turbo motor? Light, powerful, good aftermarket...?

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[Oreif]

As far as the 3.4 DOHC, this is also my conversion of choice. However, I am having a very hard time finding crate engines, or even used engines. Don't the 5-speed Fiero Gearboxes work well with the DOHC versus the 3800S/C? What has a faster 1/4 mile time with both being stock?

I also found a place based in Dallas, fastfieros.com that focuses on 3800S/C conversions. I currently have an email out to him as well.

I suppose I should first find a Fiero to start modifying. Problem is, I'm currently deployed. Would love to just fly in, pick one up (already modified) and drive home.

The 3.4DOHC stock is 220hp, the 3800SC is 240-280hp depending on the series. The 3800SC are a faster engine in a Fiero. The DHOC runs high 13's and the 3800SC starts in the low 13's.

I would caution you on going to FastFiero's in Dallas. While he has done some quality swaps in past, He did "disappear" for about 2 years and left many hanging. Lloyd is still trying to play "catch up" with the folks he burned. One swap he "started" three years ago still had the car sitting in his yard with weeds growing taller than the trunk this past summer.

I recommend shopping around. West Coast Fiero in California www.westcostfiero.com
and
Sinister Performance in Fort Wayne Indiana www.gmtuners.com

Both do high quality 3800SC swaps and come highly recommended.

 

[Dr. Sievers]

LOL I'm starting to think you work for sinister and WCF now. J/K

 

[Febreze]

Actually the Getrag is a Muncie as well. With the DOHC engine you can use the V-6 Muncie 4-spd or the Muncie/Getrag 5-spd. Most prefer using the 5-spd with the DOHC engine because of the gearing and the high RPM range of the engine. The F40 6-spd manual would be nice as well. I don't know if anyone has done a 6-spd/DOHC swap yet.

As for cross-swaps, I've seen one with a Ford 5.0 and I know of a person who used a VW VR6 engine. There was someone swapping a V-8 from a Range Rover mated to a NSX 6-spd transaxle but I never heard if he ever completed it. The problems with cross-swapping is adapting the Fiero electronics (gauges, speedo, etc.) and the different transaxle axle lengths. Many times you need custom axles made and the cost can be rather high. Some have discussed doing other swaps, But with the GM friendliness of the Fiero engine compartment, it is less expensive to find a GM engine with the power you want.

i'm looking to buy a pontiac fiero se with the 4 cylinder stock engine in it, its in goodish condition what do you think would be a good cost for it? heres a link for it http://www.ksl.com/auto/listing/3786394?ad_cid=2#

 

[melsg5]

use www.nada.com and www.kbb.com for prices and this thread was from 2009.

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[G-345783]

why don't u try a 2007 and up 3.6 high feature engine and 6 speed transmission.good luck with the wiring. LoL !