So I have read a few threads here and there, they all discuss the pros and cons of each swap. But it seems that most (not all) people swap out the 2.8 for something. My question is, how much of a difference does it make if you want to swap out the 2.5 for a 3800 or 350 small block, or N* ect. Does it make a big difference. I feel my 2.5 may be on its last legs. And I dont want to put any money into the p.o.s. engine that it is, I would rather build up something else. Any suggestions?

The only differences I can think of would be mount location on the cradle and a different wiring harness.

Being that you have to make new mounts and splice your own harness it shouldn't be any harder than swapping out a V6.

However I don't have any experience in this, so I could be dead wrong.

Well for one I have a V6 cradle just lying around now.
What about cooling, it seems like the V6 has a bunch of extra tubes here and there. Also I have a somewhat beat up v6 wiring harness and ECM would those help?

You could probably do a 3.4 swap with your V6 cradle and computer fairly easily. what transmission do you have though? I don't know about an izuzu behind a bigger engine, and gearing is to be considered. You may want to look into an ecotec swap, if you could find a 2.4 VVT with the tranny, Roger Thelin sells all the brackets, mounts, and a shifter adapter to use your stock shifter. That engine gets 34 mpg in a cobalt SS and has a conservatively rated 174 hp. With a nice solstice header and the fiero's light weight, you not only would have a much faster than stock GT fiero, but a stingy gas consumer, too.

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1984 Fiero SE, White, first love, sold...
1986 Fiero SE 2M6, gold
1988 Fiero 2M4, the Fox
1987 Fiero GT, Blue, 3.4/4T40
Still looking for that perfect CJB 88 GT...

An ecotec swap is usually deemed more difficult than a LS1/LT1 swap. The amount of work required to adapt a new transmission shift links, cradle mods, and axles would really be similar to another radical swap.

a 3.4 pushrod or TDC, or any 3800 are the best swaps for your time and effort.

Then take for example a stock 3800 sc. Once I have it rebuilt (assuming I get it from a junkyard) and the tranny attacked. what else needs to be done to make it work in an 84'? I understand there are some space issues with the belts and pulleys but that is a universal problme for all doing a 3800 in a fiero. What about cooling? Is it any different in an 84 vs 85-88?

I have never worked on an 84 myself but from what I understand if you have all the 2.8 stuff it shouldn't be much harder. I know with archies v8 kit it wont matter he gives u the stuff for either engine. Im very happy with it and would highly recommend it

I was considering a V8 but I dont think that the gas milage will work for me. Then again right now my 84 is getting an amazing 17mpg so who knows maybe droping it to 15 with a v8 wouldnt hurt that much. And I have the Entire 2.8 cradle and I have other parts but there are things here and there that are missing.

quote Originally posted by darkhorizon: An ecotec swap is usually deemed more difficult than a LS1/LT1 swap. The amount of work required to adapt a new transmission shift links, cradle mods, and axles would really be similar to another radical swap. a 3.4 pushrod or TDC, or any 3800 are the best swaps for your time and effort.

Those choices wouldn't be bad either.

I thought Roger Thelin's kit makes this much easier. I guess I'll have to wait a while longer until someone comes out with a whole transition kit..

I was looking forward to doing an Ecotec down the road. Either turbocharged or supercharged. (LNF, or LSJ) I like the idea of crazy high mpg with performance.

[This message has been edited by Austrian Import (edited 11-02-2007).]

quote Originally posted by Dizzixx: I was considering a V8 but I dont think that the gas milage will work for me. Then again right now my 84 is getting an amazing 17mpg so who knows maybe droping it to 15 with a v8 wouldnt hurt that much. And I have the Entire 2.8 cradle and I have other parts but there are things here and there that are missing.

What year is your 2.5?

There is one other good option for you that has not been mentioned (as usual. ). The 4.9 comes to mind especially when you talk about a V8 and gas mileage. Near 30 mpg with a 5 speed or caddy auto. Fits the engine bay perfectly without mods and bolts to your tranny.

It is also a good swap to come from a 2.5 with. It is almost exactly double the torque and HP of the 2.5 and lots of the parts will be re-used. It is a cheap motor to buy and not an extensive swap at all. Parts to do it can be bought from several places or made by you pretty easy. You will need to change the fuel pump with almost any of these swaps so keep that in mind. Here is some more info...

http://www.fieroaddiction.com/
http://dtcc.cz28.com/

Good luck on what ever you decide to do.


------------------
84 SE auto. - a fun original
85 SE V6 4 speed - stock, fully loaded - daily driver
85 GT 4 speed - build thread
88 Coupe 5 speed - runs and drives, needs work, patiently waiting for its turn.

[This message has been edited by Fieroseverywhere (edited 11-02-2007).]

If you just want a 2.8 here is a cheap price on everything needed http://www.kickhill.com/mechelec.html

quote Originally posted by darkhorizon: An ecotec swap is usually deemed more difficult than a LS1/LT1 swap. The amount of work required to adapt a new transmission shift links, cradle mods, and axles would really be similar to another radical swap. a 3.4 pushrod or TDC, or any 3800 are the best swaps for your time and effort.

Roger Thelin sells a kit for all of the issues you mentioned. Shifter, Tranny mounts, Motor mounts, etc. The only issues you'd have to deal with on your own would be wiring, which you'd have to do with the LS1 swap anyway. Ecotec blocks weigh 65 pounds. Your car would be much closer to 50/50 weight distribution with an eco in back. LS1s are badazz, but they're not any easier to put in a fiero than an eco. And the motor is going to cost you a lot more.

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1984 Fiero SE, White, first love, sold...
1986 Fiero SE 2M6, gold
1988 Fiero 2M4, the Fox
1987 Fiero GT, Blue, 3.4/4T40
Still looking for that perfect CJB 88 GT...

So right now I am leaning towards the 4.9 or the Ecotec. The 3800 was something that I was thinking about , but I dont want to have to worry about clearance issues , or pulley issues. Also I have heard one or two and really didnt like the sound, I dont want to spend alot of time and money on something that is just going to annoy me everytime I fire it up. Sounds like the ecotec has more potential unless you turbo the 4.9. How hard is it to get the parts to rebuild a 4.9 and are they more exspensive then other car parts? If I did a 4.9 swap I would install it and get it all in working order then want to eventually turbo it.

btw Dave, thanks for the parts, I got them home with no problems.
FYI there is a lot more room in there to turbo a four cylinder than a V8. Search username Fosgatecavy98, he has a turbo eco build, turbofiero has one in the works, wftb has a working daily driver turbo eco GT, and ccfiero350 has a blown eco build he's nearly completed. It's like the eco was made for the fiero. I'm planning on putting one in my 88 when I get back from the war. As far as parts availability, there are some places that do performance and custom 4.9 parts, but there aren't nearly as many 4.9s as Ecos sold. think Caddy versus Cavalier, Sunfire, Malibu, Vue, Ion, Cobalt, G5, etc, etc, etc. You can pick these engines up cheap and thanks to the 'tuner' market, most notably the J-body crowd, there are LOTS of performance upgrades to make your eco go fast and not sound rice.

here are a few to whet your appetite:
https://www.fiero.nl/forum/Forum2/HTML/045570.html
https://www.fiero.nl/forum/Forum2/HTML/078384.html
https://www.fiero.nl/forum/Forum2/HTML/082860.html

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1984 Fiero SE, White, first love, sold...
1986 Fiero SE 2M6, gold
1988 Fiero 2M4, the Fox
1987 Fiero GT, Blue, 3.4/4T40
Still looking for that perfect CJB 88 GT...

So what are the specs on the two? I understand that a 4.9 makes about 200hp and 300ftpnds trq? What about the ecotech? The idea of having 300 ftpnds of torque on my silly little fiero is fun, but having it more or less run out of breath at 75mph is kinda lame, probably keep me out of trouble.

Anyone have a rough Idea of what it would cost to do either, assuming junkyard rebuilds, and buying the kits or whatever brackets are required as well as the wiring harness ect. Also doesn anyone have an idea of the amount of time it would take to do one vs. the other?

...there are no differences going from a 2.5 to xx motor as going from a 2.8 (same) xx motor - especially on 86+ cars as they have the same engine harness (my 86 2.5 had all the same wiring as the 2.8 - it just didn't use them all).

EXCEPTION: 84's are a different breed and lack some wiring - extra wiring will be needed.

There are some physical differences: 88 strut towers 'invade' the engine comparment more, 2.5 fuel lines are run different than the 2.8 - but nothing that is easy to overcome.

[This message has been edited by Mickey_Moose (edited 11-05-2007).]

I think I may just look for an 87 GT with a blow motor or without one, Or just build up a motor on the cradle I have/in the garage and then put it in a car when I am ready and continue to use the 84 as a daily driver. Especially if it is an added hassle to swap into an 84

quote Originally posted by Dizzixx: So what are the specs on the two? I understand that a 4.9 makes about 200hp and 300ftpnds trq? What about the ecotech? The idea of having 300 ftpnds of torque on my silly little fiero is fun, but having it more or less run out of breath at 75mph is kinda lame,

The 4.9 doesn't "run out of breath" at 75 unless you mean can't outrun a 3800SC in the second half of a drag race. It's still plenty fast for the street. And unless you are on a drag strip you hardly are not going to notice the drop in power. Stop light to stop light the 4.9 is going to be waaay more fun than your 2.5 ever was.

Thats going to be true of just about any swap I do, really though I need to consider everything. Cost, time taken, difficulty, modability, overall power, driveability, power and torque curves, ect.

Giving what it takes to make a swap work right, it is important to take all these things in, and be sure that I will be happt with it in the relative long run. Whats the reliability like with a 4.9 and the ecotec?

quote Originally posted by Dizzixx: Whats the reliability like with a 4.9 and the ecotec?

It depends on what you mean by reliabilitty...the 4.9 is a big V8 that has few moving parts that is very stout for the amount of power that it's making. The ecotec is a much smaller, higher strung motor with multi-valves and multi-cams. More moving parts generally means lower reliability, but if you are compaing a 10 year old junk yard 4.9 to a crate ecotec it might balance out.

Those two motors have a very different personality, so which one is "better" depends a lot of what you want.

I think that the 4.9 would more closely match my capabilities as a mechanic, whereas the ecotech my desires as a driver. Very frustrating. And yeah I suppose that the reliability issues could even out, but I wouldnt be buying a crate anything due to the costs involved. Unless you can find a crate motor for the same cost as a junkyard and rebuild kit.

The eco has two cams. the 4.9 has four. The eco has one bank of cylinders, and thus, one manifold for intake and exhaust. There is no crossover, much more simple to fab exhaust for. I think the eco has much fewer moving parts, if that's the standard for reliability we're using. The eco is a much newer design, has been proven to be very reliable. It is also much lighter weight than a 4.9. The intake is on the same side as the OEM cold air inlet, and the exhaust comes out on the muffler side. It leaves a LOT more room for turbos and other mods. There is a huge aftermarket following for ecos, there is even a forum dedicated solely to modding the engine. I do not know if there is a kit that you can buy to adapt a 4.9 into your fiero, but I do know there is one for the ecotec. Roger Thelin quoted me in the $600s for every aspect of his kit, incl shifter, so you can use your OEM shifter assembly and the Getrag F23 tranny that comes with ecotecs, the motor mounts, the exhaust system adapter that will incorporate the OEM exhaust from muffler back, and the torque reaction strut. His website is here: http://www.noidearecords.com/thelinsells/misc.html Some of the guys on the forums are picking up 2.2s for 500 bucks with the motor, tranny, wiring harness and guage cluster. there are so many of these engines around it drives the prices down. I realize my argument is very one-sided here, and I agree that 300 hp behind you is going to very fun. For me, weight, balance, expense and modifiability are more important than instant go-fast. With a T3-T4 hybrid and the meth injection system wftb used on his car he gets I think low 14's and still gets over 35 mpg IIRC. Try getting that in a 4.9.

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1984 Fiero SE, White, first love, sold...
1986 Fiero SE 2M6, gold
1988 Fiero 2M4, the Fox
1987 Fiero GT, Blue, 3.4/4T40
Still looking for that perfect CJB 88 GT...

quote Originally posted by fierodeletre: The eco has two cams. the 4.9 has four. The eco has one bank of cylinders, and thus, one manifold for intake and exhaust. There is no crossover, much more simple to fab exhaust for. I think the eco has much fewer moving parts, if that's the standard for reliability we're using. The eco is a much newer design, has been proven to be very reliable. It is also much lighter weight than a 4.9. The intake is on the same side as the OEM cold air inlet, and the exhaust comes out on the muffler side. It leaves a LOT more room for turbos and other mods. There is a huge aftermarket following for ecos, there is even a forum dedicated solely to modding the engine. I do not know if there is a kit that you can buy to adapt a 4.9 into your fiero, but I do know there is one for the ecotec. Roger Thelin quoted me in the $600s for every aspect of his kit, incl shifter, so you can use your OEM shifter assembly and the Getrag F23 tranny that comes with ecotecs, the motor mounts, the exhaust system adapter that will incorporate the OEM exhaust from muffler back, and the torque reaction strut. His website is here: http://www.noidearecords.com/thelinsells/misc.html Some of the guys on the forums are picking up 2.2s for 500 bucks with the motor, tranny, wiring harness and guage cluster. there are so many of these engines around it drives the prices down. I realize my argument is very one-sided here, and I agree that 300 hp behind you is going to very fun. For me, weight, balance, expense and modifiability are more important than instant go-fast. With a T3-T4 hybrid and the meth injection system wftb used on his car he gets I think low 14's and still gets over 35 mpg IIRC. Try getting that in a 4.9.

I think you are confusing the 4.9 with the northstar. The 4.9 has one (1) roller cam. It is a two vavle per cylinder PFI pushrod motor. It weighs about the same as the original 2.8 so there is no loss there in performance. The ecotec does weigh a little less but not much. It fits the engine bay with NO mods and bolts to the fiero tranny or you can use the caddy tranny. It has the ecotec beat in both price and stock performance no contest. As for power adders the ecotec wins hands down. Reliability is very, very good on both motors. The 4.9 to this day is still one of caddies most reliable motors they ever made. Some say it is better then the northstar in that respect. This motor was used in the entire caddy line for several years so finding one should not be a problem. It also evolved from the 4.1 and 4.5 caddy engines so there are more parts available which can be swaped from one to the other.

To answer a few of your other questions...

4.9's are not that expensive to rebuild though some extra care must be taken to do it right. Remember it is an alluminum block with cast iron heads and cylinder sleeves. This means that the teardown of the motor is crutial. If you strip any bolts out of the block you will have problems. This goes for rebuilding an ecotec also. One other bonus to the 4.9 is the ECM. You can program the tire sizes into it so you can easily adjust rear end ratios for better gas mileage or performance effectivly lowering (or raising) you final drive. The biggest problem people run into with it is trying to keep thier foot out of it to get that good gas mileage. You will fall in love with the sound of it immediately.

IMHO - The ecotec will always sound ricey to me. It is stll a 4 cylinder just like all the hondas, mazdas, and toyotas. They just can't roar like a V8 can. Good luck in what ever you decide to do. High RPM screamer or High low-end torque monster, the choice is yours. Look into both and decide what is the best for you. For me, I drive on the street and don't care to rev to 8k. But I can pull a stump from the yard if I need to.


It fits with no clearance issues. Its not even alligned in this pic and it still fits. I just bolted it to the tranny and through the cradle back into the car.

[This message has been edited by Fieroseverywhere (edited 11-05-2007).]

quote Originally posted by Fieroseverywhere: I think you are confusing the 4.9 with the northstar. The 4.9 has one (1) roller cam. It is a two vavle per cylinder PFI pushrod motor. It weighs about the same as the original 2.8 so there is no loss there in performance. The ecotec does weigh a little less but not much. It fits the engine bay with NO mods and bolts to the fiero tranny or you can use the caddy tranny. It has the ecotec beat in both price and stock performance no contest. As for power adders the ecotec wins hands down. Reliability is very, very good on both motors. The 4.9 to this day is still one of caddies most reliable motors they ever made. Some say it is better then the northstar in that respect. This motor was used in the entire caddy line for several years so finding one should not be a problem. It also evolved from the 4.1 and 4.5 caddy engines so there are more parts available which can be swaped from one to the other. To answer a few of your other questions... 4.9's are not that expensive to rebuild though some extra care must be taken to do it right. Remember it is an alluminum block with cast iron heads and cylinder sleeves. This means that the teardown of the motor is crutial. If you strip any bolts out of the block you will have problems. This goes for rebuilding an ecotec also. One other bonus to the 4.9 is the ECM. You can program the tire sizes into it so you can easily adjust rear end ratios for better gas mileage or performance effectivly lowering (or raising) you final drive. The biggest problem people run into with it is trying to keep thier foot out of it to get that good gas mileage. You will fall in love with the sound of it immediately. IMHO - The ecotec will always sound ricey to me. It is stll a 4 cylinder just like all the hondas, mazdas, and toyotas. They just can't roar like a V8 can. Good luck in what ever you decide to do. High RPM screamer or High low-end torque monster, the choice is yours. Look into both and decide what is the best for you. For me, I drive on the street and don't care to rev to 8k. But I can pull a stump from the yard if I need to. It fits with no clearance issues. Its not even alligned in this pic and it still fits. I just bolted it to the tranny and through the cradle back into the car.

hmm I stand corrected. mostly. I was thinking that the 4.9 was a northstar. But a 2.0 SC eco will still beat it, 205 bhp conservative, some Cobalt SS and Ion Redline owners have dynoed their stock cars at 215 FWHP. And the Eco is not like other four cylinders, it redlines at 6500. It is very torquey compared to its Honda counterparts. True, the eco will never have that V8 tone, but 4 cyls can sound cool too, without being ricey. Also, the ecotec is aluminum in both the head and block, so dissimilar metal expansion/contraction issues are not the same as the 4.9 It is nice to have the engine already fit the mounts, though. You'd have to get the Getrag F23 with the eco to use Thelin's kit. Fieroseverywhere does have some good points here.

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1984 Fiero SE, White, first love, sold...
1986 Fiero SE 2M6, gold
1988 Fiero 2M4, the Fox
1987 Fiero GT, Blue, 3.4/4T40
Still looking for that perfect CJB 88 GT...

quote Originally posted by fierodeletre: hmm I stand corrected. mostly. I was thinking that the 4.9 was a northstar. But a 2.0 SC eco will still beat it, 205 bhp conservative, some Cobalt SS and Ion Redline owners have dynoed their stock cars at 215 FWHP. And the Eco is not like other four cylinders, it redlines at 6500. It is very torquey compared to its Honda counterparts. True, the eco will never have that V8 tone, but 4 cyls can sound cool too, without being ricey. Also, the ecotec is aluminum in both the head and block, so dissimilar metal expansion/contraction issues are not the same as the 4.9 It is nice to have the engine already fit the mounts, though. You'd have to get the Getrag F23 with the eco to use Thelin's kit. Fieroseverywhere does have some good points here.

The ecotec is a great motor for a fiero. For me though, the cost of the install is still a bit too high. Maybe in a couple years. The 205hp is only with the SC version though so keep that in mind. I am still waiting to see one alive and running in a fiero too. Even with the SC the torque still is not as high as the 4.9. 600 isn't bad for the install kit at all and I think I will have to look into this further. Thanks for the heads up on that. How much do the ecotecs run? I spent 1000 (200 junk yard motor, 355 rebuild parts, 200 install parts) for my 4.9 install. I still cant find anything to match that and give me the same bang for the buck.... but I keep looking.

Ecotec fiero - cant hear it cause the fart can muffler on the car next to it. So far the only one I can find.
http://videos.streetfire.ne...93d-99d100050229.htm

No joke though. The ecotec could make a crazy fast fiero... if you got the money. 7.62 quarter with an ecotec.
http://videos.streetfire.ne...b8c-985401786aa7.htm

4.9 fiero - gotta love that sound
http://www.youtube.com/watch?v=qZN6zlkbt7I


EDIT: One more thing on a turbo 4.9. You will have to change out the throttle body and ECM since the 4.9 ECM will not work. PBJ did the only turbo 4.9 that I know of and did a build thread here on the forum. He used a 1227730 ECM if that is any help to you. Dyno'd at 349HP 398TQ with only 5 PSI of boost if memory serves me correctly. A lot of people talk about turboing one but most are happy enough with it that they never take it to the next level. HER87GT ran that car for years and several hundred quarter mile runs and did not break it. Reliability was still there for sure.

[This message has been edited by Fieroseverywhere (edited 11-05-2007).]

:me goes on a 4.9 search sniffy: nice cars man. Yeah, only the SC 2.0 gets 205, but the 2.4 is 174, and the 2.2 is around 150, with a turbo bringing it up to up to 300 without changing the internals according to wftb. The 2.0 TC motor is 260 hp. If'n you can find one. Wait til the SS cobalt gets it for 08-09. Then it'll be more plentiful.

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1984 Fiero SE, White, first love, sold...
1986 Fiero SE 2M6, gold
1988 Fiero 2M4, the Fox
1987 Fiero GT, Blue, 3.4/4T40
Still looking for that perfect CJB 88 GT...

quote Originally posted by Fieroseverywhere: The ecotec is a great motor for a fiero. For me though, the cost of the install is still a bit too high. Maybe in a couple years. The 205hp is only with the SC version though so keep that in mind. I am still waiting to see one alive and running in a fiero too. Even with the SC the torque still is not as high as the 4.9. 600 isn't bad for the install kit at all and I think I will have to look into this further. Thanks for the heads up on that. How much do the ecotecs run? I spent 1000 (200 junk yard motor, 355 rebuild parts, 200 install parts) for my 4.9 install. I still cant find anything to match that and give me the same bang for the buck.... but I keep looking. Ecotec fiero - cant hear it cause the fart can muffler on the car next to it. So far the only one I can find. http://videos.streetfire.ne...93d-99d100050229.htm No joke though. The ecotec could make a crazy fast fiero... if you got the money. 7.62 quarter with an ecotec. http://videos.streetfire.ne...b8c-985401786aa7.htm 4.9 fiero - gotta love that sound http://www.youtube.com/watch?v=qZN6zlkbt7I EDIT: One more thing on a turbo 4.9. You will have to change out the throttle body and ECM since the 4.9 ECM will not work. PBJ did the only turbo 4.9 that I know of and did a build thread here on the forum. He used a 1227730 ECM if that is any help to you. Dyno'd at 349HP 398TQ with only 5 PSI of boost if memory serves me correctly. A lot of people talk about turboing one but most are happy enough with it that they never take it to the next level. HER87GT ran that car for years and several hundred quarter mile runs and did not break it. Reliability was still there for sure.

Cant beat the sound of a V8. And 12.5 with 8psi is nothing to laugh at either. Still the ecotech is attractive, in that it is different , and has what I see as a brighter future. Still I think I am leaning towards the 4.9 though.

What did you need for your swap? Where did you get it?

[This message has been edited by Dizzixx (edited 11-05-2007).]

I can't wait till Roger Thelin makes a kit for the LSJ, LNF. The F-35 just seems like the perfect tranny.

Could you elaborate on the acronyms, F-35 ; that is a getrad 5 spd that is newer isnt it? LNF? LSJ ; the ecotec?

quote Originally posted by Dizzixx: Cant beat the sound of a V8. And 12.5 with 8psi is nothing to laugh at either. Still the ecotech is attractive, in that it is different , and has what I see as a brighter future. Still I think I am leaning towards the 4.9 though. What did you need for your swap? Where did you get it?

You need...

~Front engine mount - 84-87 cradle contact BubbaJoe, 88 cradle look at the fieroaddiction ebay store, Or WCF sells a mount
~88 2.5 throttle cable - Mall is your best bet for this
~oil cooler or elimination kit - Summitracing.com has a good cooler for about 40, WCF sells the elimination kit, or like me I am using an auto tranny and cooler lines as my oil cooler (will not work if the car is to be an auto)
~For manual you need an 88 flywheel re-drilled with the 4.9 bolt pattern
~For auto use the caddy auto and save some money on gas and install cost
~Not necissary but definately makes it easier, 91-92 Cadillac Allante starter

Everything else needed depends on the options you decide to go with. The early 4.1/4.5 exhaust manifolds will bolt up and are stainless of about the same grade at the original fiero manifolds. You will have to decided how you want to route your exhaust and if you want to keep your trunk or not. You will need to decide between a tentioner or modifing the alternator bracket to make an adjustment there. You will have to decide whether you want a dual or single O2 sensor setup and decide if you want to get a chip programed (definately recommended) or not. There are also lots more options to choose from, Allante intake, carbed setup, intake (stock fiero, 4.9, or other).

The list goes on. Check my build and 4.9 rebuild threads for more info.

------------------
84 SE auto. - a fun original
85 SE V6 4 speed - stock, fully loaded - daily driver
85 GT 4 speed - build thread
88 Coupe 5 speed - runs and drives, needs work, patiently waiting for its turn.