I had the pleasure of driving a 3.4 DOHC swapped Fiero GT 5-speed this weekend and i thought i'd share some comments about this:
If you had asked me about doing this engine swap before friday i would have honestly said that i wouldn't be interested in this engine for a Fiero. Now, thanks to my good friend Jeff, i am seriously considering this for my own car. The engine has a lot more torque then i expected and it also revs so buttery smooth that it's not even funny. This means that it is a very good marriage to the Getrag 5-speed and it's low gears in my opinion. This engine just flat out pulled any and everywhere and was just a joy to drive. Highway speeds were especially a treat as this swap feels as smooth as silk even at 90+ crusing speeds.
Obviously there are bigger and faster motors out there but, even with one of those, there will always be someone faster that comes along. This engine really seemed suited for the Fiero in my opinion and it was a real joy to drive at any speed. It certainly doesn't lack power either with over 200 HP on tap and more available with easy mods it really has made me rethink what i might do with my own car.
Again i'd like to thank Jeff/fieromadman for allowing me to drive his freshly swapped Fiero so much this past weekend. His exhaust was the only thing that i might have enjoyed more then the engine itself. There was nowhere we went this weekend where people weren't looking as his car thundered by.
I'm checking out the build thread on this swap more closely now but if anyone would like to add any comments here about this swap please feel free to do so as i am not as familiar with this swap and engine as i am with others.
Here's Jeff/fieromadman and his car:

The engine:

And a side shot:

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Activities Director N.I.F.E.

www.fierofocus.com

I've heard that this is a great engine in the fiero too. Thanks for sharing your thoughts.

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-Chris -
Custom Gun Metal 86 GT 4.9 V8 5spd

Build up tread or MODS w/ Pics

I have never divin in a 3.4DOHC but I have had a few 2.8 that all just ...............dont cut it.
So I swaped out the 2.8 for a 3100SFI and that 87GT came to life. Great power to MPG but just not enough power for me.
Then I did my 3.5 S* and that car is fun. I am used to the ner7000 RPM shift points in the 4 speed auto. Even thou I hate autos it is all I can have if it is to stay smog legal.
Then I drove a 3800SC 5 speed, WOW. I hit the rev limmiter in a heart beat because at 5000 RPM I was not even close to the 7000 Red line I am used to.
The Twin Cam engines are AWSOME. The low end grunt of the 3800SC is great but the sound of the 7000 RPM power plant is something I love about my car. The 3800SC sounds good too, more like a muscle car. I wish I could have 10 Fieros all with different mods and engine swaps. But for now I would not trade my 3.5 Twin Cam for any thing but a N* or LS1.
I have not raced the 3800SC with my S* but I am sure he would just walk all over my 3.5. My 230 (est) HP just is not enough for the 240(factory rated) 3800SC with mods and massive torque.
I would love to see how my 3.5 will do against a 3.4
This 3.5 engine would be an OUTSTANDING powerplant with a 6 speed

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Rickady88GT QuadCam 3.5 V6

I think its a great swap too, though I find it much more enjoyable if you have TWO friends, one to push you around the driveway, and another to make vroom vroom sounds....
It'll run some day :'(

Thanks Dave for that interesting and informative post.

I have long thought the 3.4 DOHC was a good choice but had no experience or unbiassed testing to back up that belief.

I don't know what the 3.5 is or how it compares to the 3.4 DOHC.

Currently I am developing my 2.8 one step at a time and I expect I'll be happy with the 2.8 limitations. There is always somebody faster and personal driving pleasure is the question of course, not who is the fastest as your post describes so well.

If I was doing a swap though, I'd be mulling over the 3400 pushrod, vs the 3.4 DOHC vs. the 3800.

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Arn

thanks for all of the kind complement dave. I think that its a great combination for the fiero and i definatly get a thrill out of the exhaust too. Nothing like the sound of a free flowing 60* v-6. My build thread will be updated soon because of Dave pushing me to do it so soon it will be loaded with pictures.

Thanks!
Jeff

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REMEMBER: If you cant win the race you loose the argument!!

3.4 DOHC Motor Swap-14.7 in the 1/4 mile with no hook-up, crumby exhaust and automatic chip.
Better exhaust, chip, cam retarding, and driver to come... I'm feeling lucky!
www.geocities.com/j_depies

I also drove in Jeffs car when he was down here in Illinois, all I can say is wow. I know that he didn't push it to the max, and it isn't even totaly tweaked, but still, a great engine for the Fiero. Good luck with your car, and I hope you get the right chip in there soon. I know Dave will argue with me on this one, but I still think I am going to go with the 3.4 pushrod turbo engine. One being that my dad has been a GM teck for 29 years, and he has told me about the horror stories of the DOHC engines and changing ANYTHING on them, it's just a pain. The 3.4 DOHC is a great engine, and can make amazing power, but I think it is out of my experience of engine swaps.

Mike

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[This message has been edited by Golden86 (edited 08-23-2004).]

Cool! Seems to me that Fieros would have gotten that engine if it'd made it into the 90's. Didn't the car at the 20th last summer have a 3200 DOHC? Yeah... seems like a good match to me.

Brad

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quote Originally posted by Arns85GT: If I was doing a swap though, I'd be mulling over the 3400 pushrod, vs the 3.4 DOHC vs. the 3800.

This is an interesting point. I have driven all 3 of these swaps in a Fiero you listed above now. I think any swap is a personal choice of course and should go along with what the individual wants but if you'd like to hear my impressions of these three choices i'll give a breif commentary on them (i'd be happy to go into more detail with anyone who feels like discussing them though) i liked all three of these engines in the Fiero. The 3800 SC was all about brute force. The only way to describe a 3400 for me is to say that it's like a very quick more torquey 2.8 that also manages to be much smoother. I almost bought a 3400 powered Fiero in fact. The person who bought it bought it on the day i called the previous owner to tell him that i wanted to come pick it up. I have driven a built up 3.4 Camaro engine in a Fiero and the 3400 was much nicer in my opinion. The 3.4 DOHC engine, again in my opinion, had elements of both the 3800 and the 3400 and i'll explain why; while it did not have quite as much raw power as the 3800 sc it had quite a bit and it was certainly more then the 3400. The 3.4 DOHC engine, like the 3400, was far smoother then the 3800 sc and even smoother then the 3400. This comes to why i am liking this engine so much. It is pleasing to me and fits what i think of when i think of a spaortscar. It revs but has torque at the same time. It's smooth on the highway and yet will push you back in the seat. The gas mileage seemed superior to the others as well. I think we only used a 1/4 tank getting from Iowa to here. I don't normally pay attention to mileage so hopfully either Jeff or one of the other DOHC guys will come in and make a comment about this. Again i must also say that this engine seemed suited to the Getrag quite well too. This is an element the other 2 engines, in my opinion, don't have. It was very easy to get the DOHC in it's band with the Getrag. The other engines, in my impression, were more picky about what gear you're in. This DOHC engine also makes that ultra low first gear actually usable for more then just a second. As i'm pulling out of places where i would have to stop soon afterwards i could actually leave the trans in first where normally i would have to shift to second. That's not a huge deal to most but it added to my opinion on the overall goodness of this engine in the Fiero as it was so versatile.
You may have noticed that i stated 'in my opinion' or ' my impression' an annoyingly ammount of times in my post here but i did this for a reason. I enjoyed all 3 of these engines and would be proud to have one of these in my own car so i wanted to make sure everyone knew i was not cutting down any of these other choices. This is merely my own opinion when comparing them all and, like i said before, a swap is or should be what that particular individual wants or likes. What i like is not necassarily what another person would like or want in their car.

Thanks again Dave.

Really good observations for quick reference for potential swappers.

Arn

quote Originally posted by Golden86: I also drove in Jeffs car when he was down here in Illinois, all I can say is wow. I know that he didn't push it to the max, and it isn't even totaly tweaked, but still, a great engine for the Fiero. Good luck with your car, and I hope you get the right chip in there soon. I know Dave will argue with me on this one, but I still think I am going to go with the 3.4 pushrod turbo engine. One being that my dad has been a GM teck for 29 years, and he has told me about the horror stories of the DOHC engines and changing ANYTHING on them, it's just a pain. The 3.4 DOHC is a great engine, and can make amazing power, but I think it is out of my experience of engine swaps. Mike

A friend of mine here in town has a 3.4 pushrod turbo & we almost went in that direction for our swap until I drove Ed Parks' 4.9. The 3.4 turbo was great...lots of fun...but I really enjoyed the low-end torque from the 4.9. Good luck with your swap...you'll have a blast!!!!

quote Originally posted by Golden86: I also drove in Jeffs car when he was down here in Illinois, all I can say is wow. I know that he didn't push it to the max, and it isn't even totaly tweaked, but still, a great engine for the Fiero. Good luck with your car, and I hope you get the right chip in there soon. I know Dave will argue with me on this one, but I still think I am going to go with the 3.4 pushrod turbo engine. One being that my dad has been a GM teck for 29 years, and he has told me about the horror stories of the DOHC engines and changing ANYTHING on them, it's just a pain. The 3.4 DOHC is a great engine, and can make amazing power, but I think it is out of my experience of engine swaps. Mike

Oh no Mike, i have no argument here. The fact that everything you do to your 2.8 right now will be somethig that you can easily change over into a Camaro 3.4 pushrod engine is something i myself have always said. All the stuff i have done on my current 2.8 had this in mind in fact and i thought i explained that. I know a lot more about the pushrod 60 degree engine too and that may end up being the deciding facter that keeps me with the pushrod V6. When you and i were talking yesterday you were talking about making more power with the pushrod motor and that's the part i argued with. I don't think these engines are as horrible to work on as is rumored but, as i said in my original post, i am not that familiar with them so any comments about them, even bad things, are something i am interested in hearing. I definitely heard what your dad said about these engines and am keeping that in mind.
Gotta admit though Mike, my car would rock with a DOHC engine and some kind of nice new T/A sunset color. lol

here is the build thread updated with details pictures and so on. The bottom of the fist page and the second page is pictures of the build.

https://www.fiero.nl/forum/Forum2/HTML/052017.html

Thanks for all of the good words guys! This engine is really well suited for the Fiero IMHO!

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REMEMBER: If you cant win the race you loose the argument!!

3.4 DOHC Motor Swap-14.7 in the 1/4 mile with no hook-up, crumby exhaust and automatic chip.
Better exhaust, chip, cam retarding, and driver to come... I'm feeling lucky!
www.geocities.com/j_depies

quote Originally posted by Dave Gunsul: I enjoyed all 3 of these engines and................. a swap is or should be what that particular individual wants or likes. What i like is not necassarily what another person would like or want in their car.

Although I deleted the vast majority of your quote, these partial sentences pretty much sum up how I feel and where this addiction can lead to. Here's where I am so far:

88 Formula, 4.9/4T60E
88 Formula, 3.4 TDC/5 Speed
88 Formula, 3800SC II/4T65E
88 Formula T Top, Stock 2.8 /5 Speed
88 Coupe, currently undergoing rebody to Pantero and a 4.9 Swap.

I'm soooo confused.

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Ron
aka: Blackrams

Sent you a PM Blackrams about your formula. Since i have a formula 5-speed that i would put the DOHC engine into if i do go with this swap, i am very interested in your opinions of this. Thanks.

Think the 3.4TDC is fun N/A, try a turbo charged one. I got to drive Chris Wests with the 4spd and it blew my socks off. Awesome motor.

You know when I first drove my TDC hard it scared me when I passed someone. Then I got use to it, sold it and now I miss it. I'm thinking of doing another TDC, TDC turbo, northstar or 3800sc. Soooo many choices and only one car. How much boost is Chris West using in his TDC turbo? Anyone here have something more to add about a turbo TDC? Oh and looks great Fieromadman.

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Alan Frazier
'86 GT-'92 3.4 TDC 5 speed(sold)
'84 2m4 project car

Threads like this make me want to get my 3.4 done now!

One thing I'm looking forward to is passing power, the 2.8 was sufficient but I like it when a car still has power in the 70mph range. With my 2.8 I could get a maximum 130mph rpm limited with my 4 speed, hopefully I can now hit 150mph before I hit the rev limiter. Do you think a 3.4dohc will push my car to 150?

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no but i think a getrag would

quote Originally posted by crzyone: Threads like this make me want to get my 3.4 done now! One thing I'm looking forward to is passing power, the 2.8 was sufficient but I like it when a car still has power in the 70mph range. With my 2.8 I could get a maximum 130mph rpm limited with my 4 speed, hopefully I can now hit 150mph before I hit the rev limiter. Do you think a 3.4dohc will push my car to 150?

If you go for it, be sure the officier's in car camera is on when he stops you, assuming that's how you are stopped. It should make the Wildest Police Chases program. Will be tuning in to see you. Good Luck.

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Ron
aka: Blackrams

[This message has been edited by blackrams (edited 08-23-2004).]

quote Originally posted by neverendingproject: You know when I first drove my TDC hard it scared me when I passed someone. Then I got use to it, sold it and now I miss it. I'm thinking of doing another TDC, TDC turbo, northstar or 3800sc. Soooo many choices and only one car. How much boost is Chris West using in his TDC turbo? Anyone here have something more to add about a turbo TDC? Oh and looks great Fieromadman.

If I recall correctly from when I was driving it, which is hard because I was ODing on Adreneline at the time, it was at least 15psi, because I watched the boost gauge peg when I hit the gas. And I wasn't even flooring it, didn't want to break anything I couldn't afford to fix (read: anything).

to answer your question, Crzyone, the 3.4 will push the fiero into the 150's. That's all I am going say.

quote Originally posted by Fastback 86: If I recall correctly from when I was driving it, which is hard because I was ODing on Adreneline at the time, it was at least 15psi, because I watched the boost gauge peg when I hit the gas. And I wasn't even flooring it, didn't want to break anything I couldn't afford to fix (read: anything).

First I don't think Chris is anywhere near 15psi, I think it's under 10psi, call him he'll tell ya what it is.

As for the 3.4 DOHC and a Fiero, I did alot of research and soul searching to find out what would be the best swap for me and my driving style.. as many now know I just got mine back from WCF. The only thing better is to throw a TURBO at that DOHC.. I'm in the begining of breaking in the new mill and not running it over bout 4K on the tach.. First off I never even rode in one before the swap but have rode in some very impressive other swaps, V8-California Kidz "awesome", 3800 SC/IC-Skitime "different but still awesome", and 3.4 DOHC Turbo- Chris West's "awesome too" This Turbo DOHC is just the berries, fits the GT and Me to a T... I can't wait to get this sucker all tweaked and tricked out

Must..........Finnish..........Swap.....................!!!!

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Dave E

www.ltlfrari.com
Visit the NC Fieros website at TarheelFieros.org

quote Originally posted by wetpoop: to answer your question, Crzyone, the 3.4 will push the fiero into the 150's. That's all I am going say.

Thats what I thought, thanks.

I thought wcf kept the bottom end stock, and if thats the case, boost will be limited to well under 10psi. Unless your running super high octane and an intercooler of some sort, detonation can be a big problem.

Kameo, how long is the brake in period for your motor?

quote Originally posted by crzyone: Kameo, how long is the brake in period for your motor?

Well I'm thinking around 3K so that the rings set in good, I'd like to switch to Mobil 1 once that is done. You get different answers if you ask around bout the time frame for this.. I don't know what kinda break in that GM does on it's cars that come standard with Mobil 1, are they already broke in or what.. So I think I'm going to call Mobil and see what they say and maybe GM too.

quote Originally posted by Kameo Kid: First I don't think Chris is anywhere near 15psi, I think it's under 10psi, call him he'll tell ya what it is.

Ok, you're probably right. I was paying much more attention to driving than exactly what the guage is reading. I just recall it shooting all the way over when I stepped on it, and most guages read to 15psi. One of these days I'll ask. Whats yours set to? They probably built them the same.

holy crap ltlfrari your still not done?!

The mods that i want are in this order: chip (allready ordered) good exhaust, cam timing, under drive pulley, port and polish, custom set of cams, rebuild with higher compression pistons (this is where i decided if i want turbo or not cuz if i do want a turbo it will be lower compression pistons so i can get more boost). At that point i think i'll be happy!

For now with a 17 year old budget im pretty damn happy.

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REMEMBER: If you cant win the race you loose the argument!!

3.4 DOHC Motor Swap-14.7 in the 1/4 mile with no hook-up, crumby exhaust and automatic chip.
Better exhaust, chip, cam retarding, and driver to come... I'm feeling lucky!
www.geocities.com/j_depies

I've driven faster Fiero's and faster cars but the DOHC is still the funnest hands down.

ahhh the power of the DOHC.... I am very happy with my DOHC. Its the kind of car that if you put it away for any length of time, you start having withdrawals. I am an Italian car enthusiast. I own a few of them currently and have had others in the past including a 308 Ferrari. The Fiero with this motor reminds me very much of my Italian cars especially the Ferrari. It has a soul. The sound is like ripping silk very smooth and silky. With stiff gearing this motor not only is fast but quick off the line. I can shut down most cars off the line and it will hit 150 mph if you dare. IMO, this is the correct motor for the Fiero.

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What type of 0-60 times and 1/4 et times can this car get with a 5spd tranny or automatic???

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85' Fiero 5spd notchback
http://f1.pg.photos.yahoo.com/ph/bigtime1911/album?.tok=phlWNyABDV9Lapf.&.dir=/2a9c&.src=ph

65' Karmann Ghia
http://photos.yahoo.com/the_ikon1911

Jaguar XJ8 L
Audi A6 Quattro
Jeep CJ7
Lexus SC 400 *Best car ever RIP

quote Originally posted by The_Ikon: What type of 0-60 times and 1/4 et times can this car get with a 5spd tranny or automatic???

Using an auto with this engine would ruin all it's good qualities IMHO. This is a rev motor and an auto would just take most of the fun of that capability away. I would guess that it would also slow the 1/4 + 0-60 times down significantly. The flexability of this engine when mated to the Getrag was very good and i can't imagine saddling down that magnificent engine with a slushbox especially in a sportscar.

the 3.4 DOHC is great in a fiero, until something breaks.....the 3.4 is a total PITA to work on and is commonly know for it's unreliability.

but if you can keep one running they do put out a fair amount of hp and I love the powerband......

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www.audiofreeze.org
jeremy@audiofreeze.org

quote Originally posted by 86fierose: the 3.4 DOHC is great in a fiero, until something breaks.....the 3.4 is a total PITA to work on and is commonly know for it's unreliability. but if you can keep one running they do put out a fair amount of hp and I love the powerband......

The 3.4 is as reliable as any motor just as long as it is maintained such as changing oil at regular intervals coolant and filters. Ive seen them go for 150,000 miles on an original timing belt although one should change it every 60,000 miles along with the idler pulleys and tensioner. The later motors 96-97 are interference and will bend valves if the timing belt goes. I'd rather change a waterpump or timing belt on a 3.4 DOHC in a Fiero than a waterpump or timing chain on the stock 2.8, northstar or 4.9

quote Originally posted by Dave Gunsul: Using an auto with this engine would ruin all it's good qualities IMHO. This is a rev motor and an auto would just take most of the fun of that capability away. I would guess that it would also slow the 1/4 + 0-60 times down significantly. The flexability of this engine when mated to the Getrag was very good and i can't imagine saddling down that magnificent engine with a slushbox especially in a sportscar.

I wouldn't rule out an auto if you wanted a sweet cruiser. Agreed you lose a bit but a 3.4L DOHC and 4T60E would still push it around nicely. It think DOHC is still the funnest engine whether you like an auto or manual.

quote Originally posted by TK: I wouldn't rule out an auto if you wanted a sweet cruiser. Agreed you lose a bit but a 3.4L DOHC and 4T60E would still push it around nicely. It think DOHC is still the funnest engine whether you like an auto or manual.

i can't imagion putting an auto tranny to this motor, my getrag is sooooo sweet with this set up and for now i'm only running it up to 4K on the tach, just babying it along but it is so responsive, so smooth, and when the turbo spools up it's. . .. .... .it's like music to your ears..!!!

I need to get in gear and get this swap done.

Rob

.

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88 TTop coupe (CJB #95), 96 3.4DOHC/5 speed in progress

Light travels faster than sound. This is why some people appear bright until you hear them speak

quote Originally posted by Kameo Kid: i can't imagion putting an auto tranny to this motor, my getrag is sooooo sweet with this set up and for now i'm only running it up to 4K on the tach, just babying it along but it is so responsive, so smooth, and when the turbo spools up it's. . .. .... .it's like music to your ears..!!!

I agree 100%. After driving this engine with a Getrag i really can't see saddling it down with a slushbox. His car was a fine street cruiser with the manual trans so there really doesn't seem to me any reason to use an auto. There were times we were in stop and go traffic too and it was just as happy there as it was anywhere else with the manual trans. I actually believe the auto would make the engine less compliant and not nearly as responsive. A high rev motor , in my opinion, really needs a manual to make use of all it's goodness.

[This message has been edited by Dave Gunsul (edited 08-25-2004).]

quote Originally posted by Dave Gunsul: I agree 100%. After driving this engine with a Getrag i really can't see saddling it down with a slushbox. His car was a fine street cruiser with the manual trans so there really doesn't seem to me any reason to use an auto. There were times we were in stop and go traffic too and it was just as happy there as it was anywhere else with the manual trans. I actually believe the auto would make the engine less compliant and not nearly as responsive. A high rev motor , in my opinion, really needs a manual to make use of all it's goodness.

oh yeah we're on the same page for sure..

AWESOME CAR! I love that paint job! Those engines are awesome. I would have done one instead of the 4.9, but couldnt find one cheap! Cant wait to see it in person.

You didnt like that engne or anything now did you Dave?

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88 Coupe (IT RUNS)
Bottle Fed 4.9 V8 5 Speed