Since a lot of people have done the 3.4L conversion, I was wondering if anybody knows what its actual power output is in a Fiero? I know the 3.4L Crate Engine is listed at 160 HP and 194 Lb-Ft of Torque... Now GM advertises these numbers for the the engine as an alternative replacement to the 2.8L in their S-Trucks. I have seen other sources list the torque peak as high as 210 Lb-Ft.

Has anyone actually had one of these dyno'd in a Fiero? I know wheel power would be lower than these numbers, but the anount of power the engine produces in a Fiero I would imagine would be different than a truck for no other reason than it having a different intake/exhaust setup.

I am also curious as to how this engine stacks up next to the 2.8L, and to other GM engines like the 3800 S2 or even a 3.4L with aluminum heads like in the current edition Grand Ams. I'd love for some hard numbers here like 0-60 and/or 1/4 mile, but seat of tha pants impressions are good too. I also do not expect it to be as fast as a 3800... just curious how much faster the 3800 is.

Thanks in advance!!

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John
AOLIM: Fformula88

1988 Fiero Formula
1985 Fiero SE 2M6

3400=sick fast just drove mine for the 1st time.

Well I can't give you hard numbers yet other than what my dyno and drag programs give me but I can tell you that my crappy running high output 3.4-liter engine has walked away from every 5.0 Mustang I have encountered so far.

My engine differs from the GM crate engine in that I have very mildly ported heads with SI valves and a performance valve job, Borla exhaust, and FOCOA headers with a stock intake system.

Right now I am running 75k 3.4 injectors with the stock computer. As soon as I get a scanner and have a custom prom made that will fix my fuel problem I'm sure it will even be faster. It rips above 4k rpm.

There is a member here who has a stock 3.4 motor from a Camaro with a custom prom and he got his to run a 14.7 in the quarter mile.

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quote Originally posted by 88formula: Joe if your ever in my area we must have a race. Built Camaro 3.4 Vs 3400 pushrod engine.

I accept the challenge.

Sorry no dyno numbers yet. But vs 2.8 hella better!
On dry I'll break my 215/15's loose in 2nd on a hard pull. If it's wet... well let's not talk about it.
As for vs 3800 if you're running against one in a GP or Buick you'll prob take it in the 1/4. In a Fiero not fair.. but a 3.4 swap is about 2-3G cheaper.

My 3.4 dynoed at 146.3 hp and 203.X ft*lbs of torque.

that was with the restrictive spiral max and I removed the air silencer which means I get hot air into the engine.

I am going to port the TB and intake. I am rebuilding the 3.4 now because a valve let go and destroyed a piston and bent a rod.

also have ported heads, intake, SI valves, sprint headers, 3.4 injectors adjustable FPR @ 45psi, hollow cat, and IRM dual exhaust, 1.52 roller rockers and crane 2030 compucam .423"/.423" lift.

My complaint is the cam doesn't let the engine breath after 4500. this is a bottom end cam. maybe the porting of the TB and intake opening will help as well as maybe getting WCF velocity tube.

I still smoked every mustang I raced over 110 mph. Got the car up to 4800 rpm in 5th gear with 225/60/15 tires on the back.

Lou- don't blame the lack of top RPM's altogether on the cam. The GM tuned port intakes are also a restriction to high RPM's because of their long runners. I made an intake that helped get a little more top end, but not much- the runners are about half the length of the 2.8's intake. My next project is an intake with shorter runners and more plenum directly above the runners.

Some great responses so far! Thanks everyone! Sounds like everybody is very happy with their 3.4's.

I still think somebody has some times for the engine! Keep the reply's coming!

How does the 3.4 run with 2.8 injeectors? less top end, more power, less power?

it seems that everywhere I see people can't get it tuned pefect with those injectors.

Well all I know is that I had a cam from Joe Wynman on my 3.275 (.060" overbore) and that sucker liked to rev to 5500...

I believe it had .435" intake and .455" exhaust lift. you gotta let this engine breathe. Compare the lift on V8 cams and you'll know why they are making more hp/cu...

I think I have the stock cam in my 3.4. Need to check with Ed (Grooms engine). If so I may change it to something better. From 2-4K it revs very fast but after 4K it slows down. My 0-60 sucks (for the mods). It should do a lot better. I have ported everything and FOCOA headers too. I'm working in a cold-air etup to see if that improve. If not then will look into the PROM. But still I'm not convince that will be the silver bullet.

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Alex4mula
:) Red & White (:

I know that we have talked about this before but each time I see a posting like this, I get more and more confused...

Here, I am reading all this info on 3.4L motors... HIGH revs at 5500? 160 HP? 194 ft. lbs of torque? PEAK HP as HIGH as 210?

I've been told time after time that a 3.4L DOHC is the very same motor as the 3.4L TDC but... Yet again, the numbers I am hearing from the DOHC are FAR below the STOCK numbers of the TDC.

210HP and 215 ft. lbs. of torques are STANDARD with the TDC. It is TURLLY a high rev motor and revs to 7500 with no problems. Again, totally STOCK. All the numbers I read that are possible with TWEAKING the DOHC 3.4L are INCLUDED AS STOCK on the TDC 3.4L...

In fact, after some tweaking, my motor went from an actual 215 HP to now, today, to 325 HP according to the "math" but I have yet to Dyno it. The Seat-O-the-pants-o-meter says I'm pretty darn close.

I have a Lotus Esprit Turbo that boasts 330 HP and my 3.4L TDC feel VERY close, only without the slight turbo lag.

As soon as I get the dyno done, which should be soon, I'll post the results.

The mods I have added to my 3.4L TDC are the basic ported/polished upper and lower intake manifolds, big bore throttle body, better injectors, adjustable fuel pressure regulator, custom exhaust, high flow cat, ported/tuned header, custom K&N intake, underdrive crank pulley, idler pulley replacing power steering pump for low drag, platinum plus 4 plugs and 8.5 custom plug wires.

These are not extensive modifications. They are also not expensive modifications. They stock 3.4L TDC was and is PLENTY quick. My Grand Prix GTP, a considerably HEAVY car compared to a Fiero, was an under 6 second 0-60 car... Just that alone, tucked in a Fiero, would be enough

So... am I nuts? Is the DOHC and the TDC really the same motor with a "marketing angle"? I can't really believe they are...

Someone please explain it to me... factually.

One thing I do know is the DOHC is for DUAL OVER HEAD CAMS... math says TWO cams. Whereas the TDC or TWIN DUAL CAMS is FOUR cams. How many valves is a DOHC? The TDC is 24 valve I know.

Anyway, I'd REALLY like to get to the bottom of this

DKOV -

DKOV...these guys are talking about the 3.4 pushrod motor...NOT the 3.4 TDC/DOHC/Quad Cam V-6. FYI

DOHC=Dual overhead cams for each bank of cylinders=4 cams. If a v6, v8, v10, v12 etc has two cams, that would be SOHC or single overhead cam, or one cam per bank of cylinders. In this case, the 3.4 "pushrod" or "overhead VALVE" has a single camshaft inside the block driving 12 individual valves. In most cases, DOHC engines have 4 valves per cylinder and SOHC engines have 2 valves per cylinder, but there are some exceptions. Pushrod engines almost always only have 2 valves per cylinder, but again, there are a few exceptions so rare that they are hardly worth mentioning. The TDC and DOHC 3.4L v6s are mostly identical. The 3.4L pushrod engine is the one that puts out about 160hp from the factory, but could be modified to put out over 200hp.

PERFECT!!!

that is exactly what I needed to know!

Thanks guys... I was just looking through the phone book for a good shrink!

So, there is a SOHC, DOHC and a TDC... Ahhh...

I get it now.

Thanks again!

DKOV -

(lous dyno sheet)

you'll be in the low 14s in the 1/4 with 0-60 in the mid to upper 6s.

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0-60 in 4.91

Theres a OHV, which is the pushrod 3.4 we are talking about, A SOHC, which would be in a new mustang GT, and a DOHC, which is what you have (and is the same thing as a TDC, which is what mustang Cobras, civic v-tecs, ford probe GTs, etc.. have, a DOHC breathes a lot better then the rest). Most of the time the OHV has the most torque, then the SOHC is second and the DOHC coming in last for same displacement motors.

An interesting fact, the new mustang GT has more torque then the cobra, and they run side by side up to 70 or so mph... hmmm what would you buy lol.

[This message has been edited by Formula (edited 10-16-2001).]

notice the breathing problems over 4500
and that @ 5200 rpms I have 125hp and 125 ft*lbs

Hey 1fst, have you done anything to that motor or is it essentially a stock motor? (as stock as a transplanted engine gets )

Thanks for posting that dyno run too! Very nice.

Keep 'em coming

Travis with lou having those numbers there I think he should be in the upper 5 to lower 6 sec range to 60 and the qtr in the mid to upper 14's. When I dynoed my Fiero I ran a 50 shot and got 145 hp and 214 torque as my peak numbers and with a 50 shot I was running high 14's. Of course this was with my auto tranny and if Lou has a manual then I am sure that can play some sort of part in the qtr to get faster times but I still think those numbers are good for at least low 6's to 60 depending on how he drives it.

I could be wrong though of course. Just saying. One way to find out I guess.

DKov, the motor they are talking about is the 3.4 Overhead Valve Pushrod engine. This is essentially the same tech as the 2.8 V6 that comes factory in the Fiero. This engine is called the 3.4 OHV engine. It is not overhead cam. The 3.4 Dual Overhead Cam engine is quite a bit more technologically advanced. It does not use pushrods, and breathes a lot better than the 2.8 or 3.4 OHV engines. The 3.4 Twin Dual Cam and the 3.4 DOHC engines are the same motor. They both are rated around 215 HP. The engine was renamed within GM for marketting reasons and "sounds cool" factor. They orginially came in the Chevy Lumina, Monte Carlo, Pontiac Grand Prix GTP, and Oldsmobible Cutlass Supreme. Here is a good page for info.
http://fiero.cc/fiero-tdc/members/mws/swap/

is it me or dose that dyno sheet look funny?

arnt HP and TQ supose to intersect at like 5232rpms. some thing around that mark. i'm assuming that one line is for HP and the other is for TQ.

they both kinda look like hp now that i look at it again.

[This message has been edited by GTMike (edited 10-17-2001).]

that must be a big block 3.4.......

Actually thats a lot of power on the bottem end of the range, Do you shift at 4000?

our autos tend to be faster to 60 than the sticks... i've run 5-6 guys around here in their GTs one of which is a 3.2 built by ARI and he can pull me once he hits 3rd but i've got him to about 50 by at least a car length then he starts to real me in(all motor runs only). (George Palm of "The Van Shop") while they are spinning after their too high rpm clutch dump we're 40' ahead and @ 30mph already. the 350 Fieroghini at the shop is the same way. if they were'nt so dead set on 4000+ rpm dumps i'm sure we'd be neck n neck.. but i'll never tell em that...

That's true. I lost at least 1 second on launch wheelspin (2-3Krpm). Maybe that's why my 0-60 sucks

leave at 13-1500... that what i did in the SE... bit sprayin and n/a... the car makes hella torque once you get past the initial chirp and it'll pull like a train.

quote Originally posted by GTMike: is it me or dose that dyno sheet look funny? arnt HP and TQ supose to intersect at like 5232rpms. some thing around that mark. i'm assuming that one line is for HP and the other is for TQ. they both kinda look like hp now that i look at it again. [This message has been edited by GTMike (edited 10-17-2001).]

If you look closely you'll see that the curves have different scales. Torque is on the right side and HP is on the left

Yeah it's kinda of a torque monster,
I want more top end.

I should have left the stock cam but I thoought the stock 3.4 cam was the same as the Fiero cam, I'm hearing it's the gm performance cam.

The cam I have is Crane with .423"/.423" lift and 1.52 roller rockers. so that's .428"

the gm cam is .427/.455?
so if I put 1.6 rockers on the exhaust, I'll have .428/.452... who's got that program to figure out my hp and torque with these numbers...

The crane cams are so tame it isn't funny. For pulling tree stumps they are fine--torquey but nothing at the high end.

Call up a cam company and ask them to custom grind you one for your application.

no spare cash or time for that, I need to find a used 3.4 fast. A local place has a whole 94 camaro 3.4 for $700... Yet they have 4.9 Caddy's for $350...??? Figure that one out...

Anybody know exactly what cam comes with a stock 3.4????????

The stock 3.4-liter camshaft is actually not a bad camshaft. I degreed the stock camshaft and got these numbers.

Duration measured @ .050"
195 intake
214 exhaust
Lift .390 intake
Lift .405 exhaust
Lode separation angle is 106

The GM Performance 12363220 camshaft has more duration and lift but the Lode separation angle is 112 degrees.

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quote Originally posted by GTMike: is it me or dose that dyno sheet look funny? arnt HP and TQ supose to intersect at like 5232rpms. some thing around that mark. i'm assuming that one line is for HP and the other is for TQ. they both kinda look like hp now that i look at it again. [This message has been edited by GTMike (edited 10-17-2001).]

I am right there with ya! I thought so too

88Formula I am guessing the 3.4 cam numbers that you just gave were from the camaro.

I am saying this cause GM says the cam that comes in the crate 3.4 motor has the bigger cam with 427/455 lift as well as more duration.

I have also done some research and was told by one or two others that the cam numbers that you gave are about the same that someone else told me for the camaro cam. I think someone told me it was 390/420 for the camaro cam. But I am guessing since you actually degreed it then you are right. Now the only thing that is different in the 2.8 to 3.4 swap is the displacement of course and the intake manifold length and diameter. it makes me wonder if the Fiero intake pulls the hp down from 160 to a lower number. but the fiero cam is actually bigger then the camaro cam

Well if the cam you stated makes 160 hp according to Gm then I am guessing that if you put a bigger cam in that engine then you could pick up a good 10 hp or so from it. Or perhaps using the fiero intake with its smaller runners pulls the hp down from 160 to like 140 with that camaro cam.?? Who knows but I hope that perhaps you see my point in all this? In fact I dont' think I know what my point is now that I thought of the fiero intake being the big factor in the hp of the 3.4. Its late so I am probably sounding dumb.

Yea Trav you are right. A auto can be faster then a manual pending on the driver and most get really anxious when racing and lose their cool allowing us autos to take the advantage early on. which is why I like the auto, punch it and go. Don't have to worry too much about roasting the tires.

0-60 in a stick Fiero is almost certain to be doomed because of the need to shift to third before you reach 60. Unless of course you have a Quad 4 or TDC, in which case you probably have enough revs to go beyond 60 before the shift. When you're counting by .1, the 2-3 shift makes a big difference.

Well, I hope all you guys say about the 3.4 is true because I just got a low mileage motor from a '95 camaro. Just have about 2000 hours of work to put my car back together, then wait for nice Cleveland weather. I guess I'll find out next spring!

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White '85 4cyl coupe
Black '86 v-6 SE
'81 CB900F Super Sport

What are the advatages/disadvantages of more lobe separation? Is it offset by more lift?
What's the HP/torque difference between the stock 3.4 cam and the crane 2030???

I just want to see what I'm gaining or losing because I'm getting a stock 3.4 versus my over-bored 3.4 w/ crane 2030...

Lou

So the Camaro cam has less lift (.390,.405) and still that engine is rated at 160hp/200tq, compared to the crate engine which has more lift (.427,.454) and it is also rated at 160hp/194tq, I guess then the difference must be in the setup (intake, ignition, exhaust, etc) that they use for testing the crate engine to rate it. If it is intended for an S10 and they are getting the same HP as the Camaro with a bigger cam, then we may conclude that that cam in a Camaro setup will give more HP/TQ. Now, because the Fiero setup is different from the Camaro (intake, etc.) then the results will be different but I guess we can expect an improvement.

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Alex4mula
:) Red & White (:

IT Should be noted that the crate engine is for carbed engines. I would imagine that fuel injection would get you 10-20 horses so again I think that performance cam is just that. Better performance.

I'd say in the Fiero application there is a little more power judging by 1FST's dyno runs. He's getting approx 145 HP and 200 Lb-Ft of torque. I think your supposed to figure about 15-20% for driveline losses, so the actual output of the engine would be about 170 HP and 235 lb-ft of torque... give or take about +/- 5. Those are somewhat rough calculations, but probably not too far.