in my opinion, 3.4 DOHC if you have a manual, 3.8SC with the 4t65e HD if you have an auto.
you COULD run the 3.8SC with a getrag, but in my opinion it's not really worth it. The 3.4 will make all the low end torque you can safely plant on the road, but will pull HARD all the way to 7grand
as for the non-sc 3.8. i personally wouldn't even bother, but it's much cheaper to buy, and cheaper to run(gas). same amount of work to install though, and far more performance capabilities.
there are too many small difference that really come down to personal preferences, like low end torque vs high rpm hp, or gas mileage vs power, pushrod vs dohc. after everything is said and done, my first sentence sums up what i would do, and explains the SC3.8 motor/trans sitting in my garage right now
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07:46 PM
hfxfieroboy Member
Posts: 113 From: Halifax, Nova Scotia, Canada Registered: Jan 2006
Well, dont waste your time with an auto 3.4DOHC or 3.8 NA. So go with the tranny you want, 3.4DOHC for the stick, or 3.8SC for the auto. Ive never run a NA 3.4DOHC down the track, but a stock 3.8SC should get you into 13.8's, which I think is a hair faster than a 3.4DOHC 5spd
I guess I should have mentioned that the car was an auto and that brings 3 problems to the table.
1. The car is an automatic, but I have a Getrag sitting in my garage with axles, cables, slave cylinder, and wring harness still attached.
2. Wife refuses to drive a standard, but wants to borrow and drive the car to go shopping with her girlfriends.
3. I don't have a bed out there for when I finish switching it to a standard, but I do have a beer fridge!
Solution for #2 and #3: buy her a Fiero!
If I were you I'd go 3.4DOHC and 5-speed. It seems like it'd be a pretty fun car, making power all the way to 7000 rpms and shifting gears.
BTW, anyone here know how hard it would be to swap in a 3.4 DOHC mated to a 4-speed muncie? I think the engine in my '86 might be on its way out... Is the 3.4L DOHC just a 60* OHV 3.4L V6 with a change in the design for the DOHC? I'm thinking I would really like that swap, are there an detailed instructions on how to do it? How much would it cost?
If I could get a 3.4L DOHC in the '86 it'd make a FUN daily driver, then I could possibly save some cash to put either a 3800SC 4-speed auto or a LS1 4-speed auto in my '88.
[This message has been edited by Tinton (edited 10-09-2006).]
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08:26 PM
m0sh_man Member
Posts: 8460 From: south charleston WV 25309 Registered: Feb 2002
Ive got a 3800 series II from a 1998 grand prix and im very happy with it, i get good gas milage with my 4 speed transmission, at 3200 RPM at 70MPH i get 26MPG with the stock 4 speed auto you'd get 30-35MPG and 205HP 230ft/lbs its got slightly more power than the 3.4L DOHC, but it redlines at 6000 RPM instead of 7000 like the DOHC motor
basically if oyu just want more power, and your sticking with an auto id go 3800 and forget about the 3.4L DOHC
its going to cost the same amount for the install of the naturally asperated motor, or the supercharged, so basically get the motor that you can afford, if you cant find a supercharged engine swap in a naturally aspirated one.
I just started my 3800SC 5speed getrag swap. The auto's seem to be faster on these engines, but i'm not going for the fastest 1/4 mile times. Mostly doing it because I like manuals better then autos, and the availability of aftermarket parts for the 3800SC engine. I've seen a turbo kit that is putting the GTP's in the high 10's/ low 11's. I also like the 3.4DOHC's because theres nothing funner then shifting at 7K I'm a big fan of both the swap, just found one hell of a deal on a 3800SC engine so thats another reason I ended up going with that swap. fierce_gt summed it up pretty well...3.4DOHC manual, 3800 4t65e Auto if your going for fast 1/4 mile times.
BTW, anyone here know how hard it would be to swap in a 3.4 DOHC mated to a 4-speed muncie? I think the engine in my '86 might be on its way out... Is the 3.4L DOHC just a 60* OHV 3.4L V6 with a change in the design for the DOHC? I'm thinking I would really like that swap, are there an detailed instructions on how to do it? How much would it cost?
It would make no difference since the 3.4 DOHC bolts right up to the stock Fiero trannies (same bolt pattern). Doesn't matter if its a 5sp or 4sp. Most people go for the 5sp, however since the 3.4DOHC red lines at 7k, and doesn't really get into its power band until 3k, and you really want a 4sp, then you should try one of the M19 (or is it M17, whichever one it was that came with the 4.10 final gearing). Technically the ideal tranny is to use the stock M284 manual, the second idea solution is to find a 3.94 final gearing M282. However, both of those are quite rare and hard to find, but are better alternatives then the stock fiero M282 gear wise.
What is concidered a "3400" is a aluminum headed pushrod motor although the 3.4 DOHC or "Twin Dual Cam" is the same displacement, bore and stroke. With that said, I can only go by what I have experienced personally in a Fiero.
If you want a engine that IMO, fits the characture of the Fiero ..go with DOHC 4 or 5 speed. It is a 7000rpm screamer thats just loves to be rung out and rowed through the gears. Having owned a 308 Ferrari, several Alfas and Fiats I am of the firm belief that the 3.4 DOHC comes the closest to the true spirit of a Fiero, that of an Italian sports car. It sounds very close to a Ferrari. GM was going to put a 3.xx DOHC in the Fiero in the next production year but the car got killed off before it could happen. With the proper gearing, ecm, cam timing weight and exhaust a stock DOHC in a Fiero can certainly dip into the 13's and possibly high 12's depending on your configuration. As mentioned probably the best overall trans currently availible that won't cost an arm and a leg would be a 3.94 Getrag. The 4 speeds are great behind it but you will be buzzing along at about 3000 to 3500rpms at 70mph which some may not like. Even the Getrags are going to be buzzing along at about those rpms as well. Regardless, that's right where it really starts to come alive and pull all the way to its 7000 rpm. I have put about 40,000 on mine over about 3 yrs having attained the engine with 70,000 already on it and have been on many road trips in it and it averages about 24 mpg on the highway if you are easy on it, but, thats really, really hard to do because it just begs you to let it rip.
The swap is probably the easiest one to do as it bolts right up to the stock Fiero trans and uses the stock Fiero motor mount as well. Exhaust will have to be fabbed up and unless you use lowering trans and motor mounts you will have to trim the passenger side rear deck lid hinge mount to clear the front head of the engine which isnt hard to do. Probably the hardest part of the swap is the wiring harness which isn't that hard to do but requires some patience to do. I can build you a harness if you don't wan't to do the harness, just PM me.
The downside of the DOHC is there isnt alot of aftermarket speed parts for it.
If you want an auto go with the 3800 series which works great with tha config and there is alot of aftermarket support
[This message has been edited by Erik (edited 10-10-2006).]
It all depends on how fast you wanna go, what you want the install to look like, how much money you wanna spend and how far you plan on talking the HP. I have done a few 3800SC swaps, one auto and one 5 speed so I could have both sides. I wanted fasr car, with a clean install and something I could build up the HP on once I got bored with it. This lead me to the 3800SC swap and I have been very pleased with it by far. I would like to doa 3.4 DOHC swap on a 5 speed being its a pretty cheap swap and a fun swap to drive with the 7K redline. Here are a few pictures of my swaps:
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10:44 PM
Oct 10th, 2006
Scurvy Member
Posts: 865 From: Richmond, Va Registered: Nov 2005
I don't have a Fiero with either but I would suggest you take this into consideration. The 3.4 DOHC was made for a short period of time and are notoriously hard to work on or find a mechanic knowledgeable in repairing them. There also isn't much aftermarket for them nor is it easy finding new replacement parts.
The 90 degree buick v6 (3800s/c) was listed as one of the top 10 motors of the 20th century, the s/c motors have been around for over 10yrs, are still being used, and have a massive aftermarket. They are also some of the stoutest GM motors made.
not saying one is better than the other but decisions can't just be made on power and rpms
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01:24 AM
Steven Snyder Member
Posts: 3324 From: Los Angeles, CA Registered: Mar 2004
For a swap with a 4-speed the exhaust crossover interferes with the clutch release arm. The crossover will have to be modified..
quote
Originally posted by Scurvy:
I don't have a Fiero with either but I would suggest you take this into consideration. The 3.4 DOHC was made for a short period of time and are notoriously hard to work on or find a mechanic knowledgeable in repairing them. There also isn't much aftermarket for them nor is it easy finding new replacement parts.
The only thing true there is that there was no aftermarket for them. They were made from 91-97. The 91-95 are ridiculously easy to find. I've seen at least 10 since Monday and I've only been to two junkyards. All of them were complete. It's incredibly easy to work on. It's even easier to work on than the stock Fiero V6.
quote
The 90 degree buick v6 (3800s/c) was listed as one of the top 10 motors of the 20th century, the s/c motors have been around for over 10yrs, are still being used, and have a massive aftermarket. They are also some of the stoutest GM motors made.
not saying one is better than the other but decisions can't just be made on power and rpms
Agreed. Take into consideration the whole powertrain and what the car will be used for. Canyon driving with a manual transmission? 3.4 DOHC with a 5-speed, hands down. Drag racing? Or cruising around town with an automatic transmission? 3800SC, no question about it. It makes more power for the dollar. If I wanted an auto I couldn't see myself putting in anything but a 3800SC, unless I could do a turbo Northstar in California.
FYI I have been driving a 3.4 DOHC with a 5-speed for almost a year now. It's my daily driver. It puts a smile on my face everytime I wind it out to 7k. It's quite fast and the sound is phenomenal.
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02:42 AM
Erik Member
Posts: 5625 From: Des Moines, Iowa Registered: Jul 2002
Originally posted by Steven Snyder: FYI I have been driving a 3.4 DOHC with a 5-speed for almost a year now. It's my daily driver. It puts a smile on my face everytime I wind it out to 7k. It's quite fast and the sound is phenomenal.
Agreed, this link courtesy of fellow Pennock's member "Race" shows "a bit" of what you can expect from a DOHC powered Fiero. Its about 1/2 to 3/4 of the way through the video http://video.google.com/videoplay?docid=6677139960123215021&hl=en This is my DOHC Fiero passing Race up on a road trip a few days ago and fairly getting on it in third and then shifting to fourth where the car really started to pull up to about xxx in very short order to where I was "Holy crap! Slow down! you got a corner coming up really fast, even though it was about a mile away still ..I really had a smile on my face at that point. Beware, the DOHC is not for an inexpericenced driver as its power and speed capability can really be deceiving ..
[This message has been edited by Erik (edited 10-10-2006).]
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03:13 AM
Steven Snyder Member
Posts: 3324 From: Los Angeles, CA Registered: Mar 2004
3800 sc 2 gets my vote I love this engine, Easy to work on, Easy to upgrade, Tons of aftermarket support for the engine, Having something that hauls butt and realiable at the same time.
Looks pretty inside a fiero engine compartment. The only downside to this swap is it aint cheap if you want a realiable swap . And even if you manage to do one cheap, It will still cost you in the long run ( Aftermarket aftermaket hint hint toys toys and more toys for this engine )
Another downside is way too many ppl are doing them these days, Soon it will be a option in a fiero if buying one from someone.
Both are nice swaps but my vote goes to a 3800 sc 2 stick or auto ( If using a getrag), A izusu would be nice for this engine, If you don't shread second gear.
FEAR MY STOCK HEADERS !!!
[This message has been edited by 86fieroEarl (edited 10-10-2006).]
Originally posted by revin: Huh Steven....1-Auto + 1 5speed = 2 swaps NOT a "few"
And the two pics you posted are both autos !!!!
Good eye Kevin--you such a perceptive little BOY!!!! But yes I have done a few swaps into 3 different cars:
First swap was the RED motor/auto trans above into my 88 T-Top that has WCF headers, 1.9 rockers. 3.4 MPS and 4 inch CAI Second swap was built SILVER motor/auto trans in my 88 T-TOP that has cam, IC, P/P blower, LS1 TB, 3.0MPS, ECT..... Third swap was the Sliver powertrain pulled from wrecked T-Top car into white Coupe with same MODs as above Fouth swap was the RED motor, slapped on a 5 speed and is now in my 88 GT with the same MODs above with Spec clutch
So thats 3 swaps that where started from the begining to the end with parts and installing. The one swap was just a powertrain swap but still is a swap being things had to be changed on the car it went into. The only thing the auto swaps share are the engine harness and a few other minor things. I know this doesnt add up to the one swap you have done 4 years ago but should be close. Or atleast should add up to that last oil change you did where the oil ended up running down your driveway into the street-LOL--Think you can change my oil at the show, that if you can do it right without making a mess.
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10:01 AM
5.0Vert Member
Posts: 287 From: Hurst, Tx, USA Registered: Mar 2005
The only downside to this swap is it aint cheap if you want a realiable swap . And even if you manage to do one cheap, It will still cost you in the long run
There's an old adage that goes, "Fast, Cheap, Reliable, pick two." There's a reason why you can only pick two , regardless of make,model,etc.
Humm...So you would like to do a 3.4 DOHC swap! Well, lets talk!
quote
Originally posted by MstangsBware:
It all depends on how fast you wanna go, what you want the install to look like, how much money you wanna spend and how far you plan on talking the HP. I have done a few 3800SC swaps, one auto and one 5 speed so I could have both sides. I wanted fasr car, with a clean install and something I could build up the HP on once I got bored with it. This lead me to the 3800SC swap and I have been very pleased with it by far. I would like to doa 3.4 DOHC swap on a 5 speed being its a pretty cheap swap and a fun swap to drive with the 7K redline. Here are a few pictures of my swaps:
I think it comes down to what you want it to look like you can make both the 3.4dohc and 3800sc make good hp if you want i mean put a turbo on the 3.4dohc and it will make more hp than the 3800 sc but if you change the pullys on the 3800 you can pump up the power and both of them stock are close on power stock i think the 3.4 dohc made 225 hp and the 3800 SC mad 260 hp only 35 hp diff so i think it comes down looks and sound due to you have a push rod engine vs a over head cam engine and one is a 60 degree v the other a 90 degree v
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05:05 PM
86GT3.4DOHC Member
Posts: 10007 From: Marion Ohio Registered: Apr 2004
I think it comes down to what you want it to look like you can make both the 3.4dohc and 3800sc make good hp if you want i mean put a turbo on the 3.4dohc and it will make more hp than the 3800 sc but if you change the pullys on the 3800 you can pump up the power and both of them stock are close on power stock i think the 3.4 dohc made 225 hp and the 3800 SC mad 260 hp only 35 hp diff so i think it comes down looks and sound due to you have a push rod engine vs a over head cam engine and one is a 60 degree v the other a 90 degree v
Its 205 for the 3.4DOHC, and 240 for the 3.8SC +/- depending on the years
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07:52 PM
PFF
System Bot
hfxfieroboy Member
Posts: 113 From: Halifax, Nova Scotia, Canada Registered: Jan 2006
I like the way this post is turning out. Now if I can just here about a race between the two or see a video of a DOHC vs A 3800SC?
After reading and seeing the video posted by Erik, I might just do the 5spd swap.
But I did get a 3800SC (I know where there's a couple for $750.00 CND each) would the stock fiero automatic be able to with stand the power? I like to drive my cars and had to replace the tires on my Camaro about every 2 months!
------------------ hfxfieroboy
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09:41 PM
5.0Vert Member
Posts: 287 From: Hurst, Tx, USA Registered: Mar 2005
I like the way this post is turning out. Now if I can just here about a race between the two or see a video of a DOHC vs A 3800SC?
After reading and seeing the video posted by Erik, I might just do the 5spd swap.
But I did get a 3800SC (I know where there's a couple for $750.00 CND each) would the stock fiero automatic be able to with stand the power? I like to drive my cars and had to replace the tires on my Camaro about every 2 months!
You'll need to get the 4t65e-hd, or whatever that trans. is that comes with the motor.
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09:49 PM
Saber49 Member
Posts: 937 From: Ontario, Canada Registered: May 2004
You'll need to get the 4t65e-hd, or whatever that trans. is that comes with the motor.
agreed... trust me its like 2 different cars.... the 3 speed is really a powersapping trans... ive had both on my 4.9 and the 4speed auto really lets the engine loose.... night and day... i kid you not
like i said not much HP diff in the two engines and if you start to mod them you can get the same power out of both so what sound and look is what it comes down to if it was me i would take the 3.4 i like the way they look and sound
I like the way this post is turning out. Now if I can just here about a race between the two or see a video of a DOHC vs A 3800SC?
After reading and seeing the video posted by Erik, I might just do the 5spd swap.
But I did get a 3800SC (I know where there's a couple for $750.00 CND each) would the stock fiero automatic be able to with stand the power? I like to drive my cars and had to replace the tires on my Camaro about every 2 months!
The stock Fiero trans will last about 3 seconds into a WOT run so if your going auto, you must go with the 65E-HD. Either way you go, I dont think you will be disappointed in either swap, both are way better than the stock 2.5/2.8. A race wouldnt really prove anything because of all the differance inbetween the motors and the drivers. If you wanna a motor you MOD to HELL and get tons of HP/Torque, then go with the 3800SC on an auto. It you want a high revving motor that has good power even in the upper RPMs and that pulls forever thats attached to a 5 speed, then go DOHC. Like I said, either way you will be happy at the end, just expect to pay more for the 3800SC swap.
What trannys are you guys mounting to these 3800s? I read the 3.4 mounts directly to the stock 5 speed, but I tend to agree--the 3800 has many more options, is much more popular and having many years experence with that engine in 3 f-bodies.. I'm very convinced that's one of GM's better engines. Not that the 3.4 is bad at all--in fact I'm driving a 95 Firebird with that and I love it, but my modding ability is more limited with that engine than it's latter 3.8.
Im just wondering what mounts to the 3800 and does the 3800 use any of the stock mounts? Anyone have A/C on it?
I have a dead Duke in the back yard and I'm looking for a nice long project
I like the way this post is turning out. Now if I can just here about a race between the two or see a video of a DOHC vs A 3800SC?
After reading and seeing the video posted by Erik, I might just do the 5spd swap.
But I did get a 3800SC (I know where there's a couple for $750.00 CND each) would the stock fiero automatic be able to with stand the power? I like to drive my cars and had to replace the tires on my Camaro about every 2 months!
can't say that i've ever seen one - but if you wait till the spring you may see a race between lil'devil's 11.7 3800sc and my unknown 62-1 turbo 3.4dohc.
i would never use the fiero 3speed auto - plus the 3800 uses the electronicly controlled 4speed - its wortht he little extra to use its 4speed
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07:14 PM
hfxfieroboy Member
Posts: 113 From: Halifax, Nova Scotia, Canada Registered: Jan 2006
I'm hoping to start the engine swap in January, then paint and interior work, and have it finished and ready for mid to end of April. Right now I'm stripping the car and repairing / replacing what used to be metal.
January may seem like a long time but I've been debating this for 6 months. (Psst, videos!)
I'm a big fan of both the swap, just found one hell of a deal on a 3800SC engine so thats another reason I ended up going with that swap. fierce_gt summed it up pretty well...3.4DOHC manual, 3800 4t65e Auto if your going for fast 1/4 mile times..jpg)
..I really had a smile on my face at that point. Beware, the DOHC is not for an inexpericenced driver as its power and speed capability can really be deceiving ..
