Most power from the 3.4 DOHC?

[Mach10]

So tell me Doc... what do I have? It's bad isn't it.... :P

Yeah, it's bad.

The only thing I can recommend is an emergency engine transplant.


I haven't been able to do a 3hr engine drop... Or rather, not 3 contiguous hours. I usually do fine for the first 1.5hrs... But by then I've nailed off a case of beer and I tend to forget what I was doing.

The next morning I can hav the rest done in the other 1.5hours... Even with the headache



Seriously though, both the 3800SC and 3.4TDC have pretty flat torque curves. The 3.4 would arguably be a lot easier on the drivetrain, as long as you don't shift like a spastic retard.

[ryan.hess]

So tell me Doc... what do I have? It's bad isn't it.... :P

Yeah, it's bad.

The only thing I can recommend is an emergency engine transplant.

fweew... good thing I've got a northstar then.

I'm encouraged by the 250whp n/a 3.4dohc... That's incredible.

[FieroWannaBe]

hehehehe... I love the fiero crowd!

1) My backyard mechanical skills can best be summed up with the following statement:
a) Oil change? Is that like spare change?
b) I can fix my own flat tires
c) I have mastered the v6 Fiero water-pump replacement
d) I can have the subframe out on my floor in less than 5 hours

2) The thought of a wiring harness stretched out on a work bench:
a) Makes me sick to my stomach
b) Makes me feel slightly dizzy
c) Where the hell did I put that shop manual
d) Makes me SO horny.

3) I have driven a stock 2.8 Fiero and
a) Am scared to turn corners
b) I can drive it normally
c) I can keep the car mostly in line under most conditions
d) I can keep the tail steady on a flat 4-wheel slide in the snow.

4) Based on what I know of the Fiero's handling and performance characteristics,
a) More low-end grunt is what I crave
b) More top-end power will make it more enjoyable
c) A flat torque-curve gives me piss-shivers
d) Nothing short of a fire-breathing ground-pounding monster will keep me hard.

5) I like driving my fiero
a) Once a month
b) Once a week
c) Every couple of days
d) Daily driver... Booya! until it breaks, currently i need a transmision rebuild

6) One word/phrase that bests describes my automotive budget
a) 99c bin @ local car-wash
b) Salvation Army Re-Store.
c) I live at home, have job, pay no bills.
d) Drug Dealer.

[FieroWannaBe]

there is 1 guy on here from time to time called kevwood. he had the heads done up and put them on a otherwise stock motor(and i mean stock as a rock) and put down 250 to the wheels n/a.

what does "heads done up" mean? Porting? Cams?

they were ported and some shaping was done too i think. shit i don't remember, use the search.

fierowannabe, if you are looking for 12's and u like the lq1 only way that will happen is with boost or n20 without throwing a ton of money into it.(but it would be nice to see btw)

In design, IMO the lq1 has more potential overall.

if u have the $$$ and want to have a truly unique setup with custom goodies go lq1. if you are not too loaded and just want to run 12's and do not care how, go l67.

little more food for thought, cadi n* fieros run 12's stock. and i am sure a 300+horse sbc would probably yield good results as well. 1 last tasty morsel for you. ls1's make an assload more power when carbed. i remember looking it up be4, the gain by just going to carbed is sick.

I know I would need to boost it, I want a quick car, but smooth too. Thats why the lq1 intrigues me, its a nice smooth motor, but my concern is thats being based off the 60*, is its ability to accept the turbos right, the numbers have been impressive. My concern is the stock oiling system, especially when putting a turbo on it.
Around here, N*s cost about 1200$, lq1 600$, l67 850$. My current budget is tight, but this is going to be my project for next winter. N* is out of the question, but I want one.
the l67 would be great but, I also want to autoX, so the lq1 would be better with its higher revs. Im at a crossroads. That why i need you lq1 guys to convince me. Any one break 350Hp reliably?

[ryan.hess]

Around here, N*s cost about 1200$, lq1 600$, l67 850$. My current budget is tight, but this is going to be my project for next winter. N* is out of the question, but I want one.
the l67 would be great but, I also want to autoX, so the lq1 would be better with its higher revs. Im at a crossroads. That why i need you lq1 guys to convince me. Any one break 350Hp reliably?

what kind of budget are you looking at here total?

[FieroWannaBe]

what kind of budget are you looking at here total?

On putting the motor in the car, includeing th emotor 1200$, Im thinking i can do it with the lq1, maybe close on the 3800, but i know thats impossible with a N*, mabye after college.

[Mach10]

Okiedoke.


You've got a couple of contradictions here. You say you want an all out ground-pounder, but you also say you want an autocrosser.

The problem is that when you get up in power, you lose the streetability that you MUST have in autocross. Specifically, (and especially in a car like the fiero) you need the throttle-response to keep the tail section where you need it.

You say you can keep the Fiero on the straight and narrow under all conditions. That's good. I'll take it at face value. But that means that you understand the dynamics that play in keeping the tail where you need it. A little oversteer here, understeer there, depending on the corner and the situation. To do that in a M-E, RWD car you MUST have a responsive and accurate throttle.

When you get to a certain point (especially with a turbo) in terms of performace, you lose this ability. big-breathing motors tend to have asomewhat ragged powerband on the lowband, and a done-to-the-tits LQ1 will be no exception. Which means that it will tend to hesitate somewhat (or the response will be somewhat flat) until it comes "on-cam" (or on-boost) and then the flood-gates open and the power's all there. They call this being a "hysterical" motor.

In an autocross/handling point of view, you can't have this. With boost, you will get a torque-spike as soon as the manifold goes from vacuum to boost. On a head-heavy cammy motor, it's much the same. Even the 215hp of the LQ1 is more than enough to screw with your line if you try to tap it in too fast. With an extra 100hp of forced induction, the car will be a bit of a handful. The problem with a turbo is that unless you keep the turbine small and fast spinning, the lag will make you spin out each and every time you try to nail the gas halfway around the corner (which is the normal mode of cornering in this car.).

A supercharged motor will alleviate this somewhat, since the response is somewhat more linear. But again, with a 3.25" pulley, it will be VERY touchy. You won't have a lot of degree of control in terms of engine output. And at a certain point it's more binary. As in On or Off.

Another contradiction is that you want all-out performance, but you don't want to pay for it.

Now, it's very good that you can do the work yourself. I did it myself, and it cost me about $3000cdn to get a bone-stock USED LQ1 running. And the bastard blew out a cam follower

Of the total cost of the swap, the cost of the engine was $500. That's $2500CDN of various other bullshit. Man, I couldn't even tell you where it went. Suffice to say that as I put it together, I found stuff that needed to be done.

Doing the work yourself saves a bundle, but you have to accept that there are things that you WON'T be able to do, that you'll have to outsource, and that with any used engine, you are in essence taking over someone else's problem. You can't assume that any used engine will work for 200,000 miles and not look like an idiot after 4 months. You have to make the best informed decision that you can, but be prepared to sink the money into it as it needs it.

Another contradiction here is that you are wanting 350hp reliably. I won't say that it can't be done. However, realize that you are pushing over 1.5hp per CI. That's a LOT of stress on stock internals. I don't think it'll necessarily come apart on you(but it's always a risk on any motor), but it will almost definitely be the nail in the coffin for an already used and worn-in motor. If you are going to try and push that kind of power, expect things to wear out at a FAST rate. Especially if you want to rev it high.


I like the LQ1. The temperment of the engine matches the Fiero's handling characteristics beautifully. I wouldn't want more torque as to make it a chore to drive. My rebuild next month is going to focus on some extensive head and intake work, to see if I can't lay down 250hp at the wheels like Kev.... I'm not expecting so much, since the shop he used is using some pretty insane new techniques. I do however have a very good machinist with a lot of headwork experience. We'll see what can be done. By the same token, I'm also spending $2200 to have the block and bottom end rebuilt properly, with a good balance and stress relief etc.

I'm sure there will be lots of quips about how so-and-so has been running a million and a half miles on an unopened bottom end with 400hp to the wheels... Every motor's different inside. GM didn't have that much in the way of tolerance control, so some are most definitely better internally. It's luck of the draw. So I'm taking out some of the variables.

The budget you are talking about is just not feasible. Not for any of the motors. You will need at minimum 4 times the price of any of the motors you listed there to take into account all kinds of things. Seriously, while the websites make the process look easy (and it's not that hard) an engine swap will ALWAYS nickel-and-dime you to death.

And if you manage to put it together for bottom-dollar, how can you expect it to hold together by cutting corners?


I'm not trying to discourage you. Mostly, if you want to do the swap, you need to sit down, think about what you want, make a decision and stick to it. The buy/sell sections of these kinds of forums are FILLED with junk that people have just given up on because of either a) lack of planning, b) lack of financing, or c) lack of discipline.


You are worrying FAR too much about the end result. With your budget, and given that you've never done an engine swap before, it's NOT possible to get to your goal in the immediate future.

My recommendation:

A) Pick a motor
B) STICK with it
C) Put it in, STOCK
D) Get it running right
E) Drive it for 6-12 months to sort out any bugs
F) Rip it apart, and start fresh, building towards the goal of 350hp

Don't worry a lot about the so-called "potential" of any particular motor. There are ALWAYS trade-offs.

The 3800SC is easy to give more power. Just throw on a smaller pulley and crank the output to some 300hp... Right, except that the shallow ring-lands and extra-tight rings aren't going to thank you for it. A single detonation (a big concern, especially on a transplant) can land you back in the garage picking bits of shattered piston ring out of your heads. Anything that goes wrong with the SC will cost you dearly in terms of machine work. From what I hear, parts for the 3800 aren't any cheaper than the 3.4 either. Superchargers are notoriously hard on your driveline, especially when shifting, as residual volume in the intake when the revs drop will cause a bit of a pressure spike, which sends a torque-shock down the driveline. This is in addition to the additional rotating mass from the 'charger. When you try and powershift, there's a whole lot more rotational energy that's going to have to be soaked up somewhere. In low gear, that means barking tires. In high-gear, it's the clutch, gear-teeth and output shafts that have to eat it. And on top of that, there's the sad fact that the 3800SC is one heavy bastard of a motor. All together (iirc) it's heavier than a smallblock chevy. Its wide, it's deep, and it's got 75 lbs of junk sitting on top of the heads. It will throw your weight balance at least as much as an SBC swap. If you give it the stronger tranny it came with, expect a good 200lb weight gain on the rear.

The 3.4 is a nicely balanced motor, the powerband is smooth, and the temperment is perfectly suited to the fiero. the motor is pretty light, within 30lbs of the stock iron-head 2.8. The bottom-end is fairly well balanced, and with the exception of some casting flaws in the oil-returns is very much over-oiled. The 3.4s suffer from some of the other problems that the 60ºs had, namely leaking distro-shaft seals. But they are easy to work with. Hell, it's easier to work on in a Fiero than a Z34


At the end of the day, the choice is up to you. Just make sure you get ALL of your ducks in a row. Or else *I* am going to be buying your junk off of e-bay

[ryan.hess]

Okiedoke.
Now, it's very good that you can do the work yourself. I did it myself, and it cost me about $3000cdn to get a bone-stock USED LQ1 running. And the bastard blew out a cam follower

Of the total cost of the swap, the cost of the engine was $500. That's $2500CDN of various other bullshit. Man, I couldn't even tell you where it went. Suffice to say that as I put it together, I found stuff that needed to be done.


...the motor is pretty light

good post, couldn't have said it better myself. I spent about the same (USD though ) getting a used $800 northstar running in my fiero. It's the little things that eat it up. Hoses need hose clamps, wires need new split loom tubing, oops, I don't have an axle nut socket... etc...

I have to disagree with you on the 3.4 being light though. It's heavy. It's heavier than my northstar.

Chevy 3.4 liter DOHC V6- 492.5 lb.
Cadillac 4.6 liter Northstar V8- 468 lb.

All accessories. See here: http://www.fiero.nl/forum/Archives/A...-2-061812.html

[Mach10]

Uh... I'm shocked, actually... Me and a friend were able to pick it up off the back of a truck with less difficulty than loading a 350...

Is that on the cradle with a trans? 'Cos that seems REALLY heavy.

I know the 2.8 isn't a featherweight itself... But I seem to remember it at around the 350lb mark with accessories. I can't see the 3.4 being 150lbs heavier!

Of course, my memory could be faulty!

Screw it. I won't argue... I'll just weigh the pig when I take it apart next month

[dohcfiend]

OMG. right when i thought the interest in the lq1 was dead, i turn my back for 1/2 a day and look at the madness!! i love threads like this. alot of creative thougts on here and so many good replies i will not even bother using the quote.


mach10, you 1st reply under my last one(not counting this one) hilarious. the last one was very informative and well thought out.

the "potential" factor i was referring to comes from a couple things. 1st off when gm 1st developd the engine it was putting out 275 or 280 streetable hp, next thing are the headflow numbers. they have been posted by several different peeps and not posted byt a few more peeps and i haven't seen an intake flowing under 250cfm@370 yet(usually numbers i have based this off of go between 252-260)

series8217 and husky: sweet!!! i didn't know about that. nice contribution.

fierowannabe: that will be a very tight budget to understate.

i have a very convincing argument for you now. out of your choices the lq1 is the ONLY engine you will be able to afford with that budget and that is IF you get a good used one. with that budget, you may want to be thinking 3.1 pushrod, 3.4 pushrod, 3800 or lq1. but that is a maybe on the lq1.

[ryan.hess]

Is that on the cradle with a trans? 'Cos that seems REALLY heavy.

engine with all accessories and manifolds, etc, as it would be installed.

crate motor weighs 440 with no accessories..

[FieroWannaBe]

I completely hear what your saying everyone, and i understand, the swap isnt goign to be cheap, but i have faith in my abuilities. But, i do know i set my budget low, and truth is i will probally go over it, but i set my target low aso to not go overboard on mparts right away. Iv done motorswaps in other cars, and i understand neeedingnew parts, or a fix. I have friends that can help too, access to a machine shop. And i dont plan on building an insane motor and dropping it in, I want it to run first, im just keeping an eye out for the future of the car.

And true there is a difference in what I WANT and what I HAVE, but isnt there fro almost everyone? When i say i want in insane powerhourse, I dont mean a 500hp 500ftlb drag machine i mean something close to 300hp with a nice clear curve, and yes the driveline is a concern when it comes to power. I have been researching swpas in fieros for 2 years, and im ready to start collecting parts, im not dropping my cradle tomorrow or anything, I'm trying to weigh out my options.
My main goal is trying to come close to 100hp per liter, its been done in lots of cars, and id like to see it in mine. I want to autocross, but i dont want to be slow, either, truth be told im a bit of a tuner, so i hang with an import crowd, and am around very efficient (power wise) motors. thanks for the concern, but ill be ok trust me Ive experianced lift throttle oversteer more than once.
I just wanted to see how powerfull modded lq1's can become.

[Mach10]

Pfft. Lift-throttle is easy to avoid, just keep your foot steady.

What's REALLY fun is snap-oversteer once you put a real motor in a Fiero

While we're on the subject of budget, I used to think like you did, but I've done two engine swaps myself. Setting the budget low with the expectation of going over doesn't work. You might as well not set a budget at all.

Set yourself a realistic budget, and if you can't afford to do it all at once, buy the parts in stages, and take a break until you can afford the rest.

One more thing. What's the baddest Fiero you've actually DRIVEN?

[fieromadman]

You should take a ride in my car sometime. I hope to makeing close tot he power that you desire this spring, you could ride in it, or perhaps drive it now and compare i to later. That may help you make the decision. I know that the Lq1 could do what you wanted it to, but it may just cost a bit of money. And as far as the $1200 dollars goes.. hehe, yeah 'nuff said.

Give me a call sometime again I'll be home this weekend if you want to take a ride/drive.

And also as far as the tranny thing goes.. well i jsut bought another one, lets put it that way. Granted i beat the ever loving piss out of my car on a daily basis, it probalbly could have lasted longer with a bit of restrain, not that its even really broke, just that there is a bolt hole missing out of the case!

[FieroWannaBe]

It would be cool to finally ride in your car, well, i think my trans needs a rebuild/replace so my budget is already over my estimate, Ill start a different thread for that.
I can go for a ride this weekend if you want to, interested in the races this weekend?