The Tao of the 3.4 DOHC

[95MonteCarlo]

I am looking for any web sites books or personal experience related to the 3.4 DOHC V6 available from 1991 to 1997 (?). My engine is a 1995 with a little over 165k miles on it. She has left daily driver status and is finally getting the attention she deserves. She was the first new car I ever got, and I plan on a complete tear down and performance rebuild. She is one of the first 1995's made and to me that means something. I also plan on swapping the 4t60-e (heavy duty) in it for a 4t80-e because of the supposed increase in strength that the 4t80 offers over the 4t60-e. Does anyone know how much stronger this transmission is? I’m trying for an honest 275 hp on motor, if not closer to 300, and I know the stock trans just won't cut it.

I am already a member of the 60 degree v6 board so any other sites are welcomed. The odd thing is that most of the people willing to take these motors on seem to be Pontiac Fiero owners, not Lumina or Monte Carlo owners. ANY personal experience or knowledge of this power plant is more than welcome. I am following the first rule of hot Roding folks: rod whatcha got. I don't want to do an L67 (3.8sc) swap or one of the 4.5 caddy motor swaps. I want something unique.

Please PM me or reply to this thread with words of encouragement or advice.

Thanks in advance for any help or curiosity or just to stop by and check in on my progress.

[95MonteCarlo]

There are some of you who may read this and ask, why is this guy working on such an odd ball engine. The reason is that this motor is an odd ball and there is so much untapped potential of this motor. From the reasearch I have done online, the tech used to develop the 3.4 went on to build the 4.6 northstar.

Even if this info turned out to be bogus, this thing is a monster waiting to be woken up and unleashed. They are finicky, but when mine was in top form I could keep up with mustangs, camaros and imports in my hometown feared my approach. I dont want to put it perfectly back to stock.

The people who love these cars and these motors know they are on the outside looking in. So I know its a chalenge, and thats one of the reasons Im doing this.

[tom3]

Bought a new 94 Olds with this powerplant. Very impressive performance-wise, and good fuel economy to boot. Really set you back in the seat and deliver 28 mpg or so on the road. Sure not a trouble free engine. Head gaskets, seals, absurd alternator location that contributes to early failure and near impossible repair just to name a few items. I've always thought this engine would be awesome in a short bed S10 pickup though. That tranny might be fine for many thousands of miles. GM has a pretty rough standard for rating a transmission and they did de-rate that engine to suit from what I've read, but I'd guess you could up the power quite a bit without problems.

[MrCritical]

Best of luck to you.

I don't think you picked an easy upgrade, but think of all you'll learn.

Let us know what kind of aftermarket support you come up with.

[F14CRAZY]

A little expensive but can you cam it?

[95MonteCarlo]

Originally Posted by F14CRAZY

A little expensive but can you cam it?

Well so far I have found that it’s possible to re-grind the stock cams. A couple of years ago there was also a local dealer with a performance parts window who told me that GM performance parts made a hotter set of cams. There is a timing mod for the 94-95 heads that sets the timing 13* BTDC that is said to get more low end at the cost of a really rough idle. If I went with a custom grind I'll probably be looking at about 2 grand, and for a 20 or 30 hp (if I'm lucky) gain that’s a lot of green to shell out.

Another popular mod is to take the upper intake from the 96-97 3.4 DOHC and keep the 94-95 lower intake, cams and heads because they flow at a much higher rate. The 94-95 intake is one piece and the 96-97 is either two or three (I can't remember which). The down side? You have to go with the OBD II computer to run it. This would mean (Yea! ) more wires!

[Slideways]

Wish I could help. In the meantime, I say go with the tried and true hot-rodding methods. Do you know any good cylinder head porters?

[bouda]

You know you can turbo just about anything. Not saying it'd be easy.

@Tom3 3.4 dohc in a shortbed S10 you say, hmm. Nah, I don't have that kinda money.

[95MonteCarlo]

Originally Posted by bouda

You know you can turbo just about anything. Not saying it'd be easy

@Tom3 3.4 dohc in a shortbed S10 you say, hmm. Nah, I don't have that kinda money.

The Question is how much would a turbo hurt my driveability and reliabiltiy? Yeah I know which motor Im talking about in terms of reliabiltiy.

The turbo is a real popular mod with some of the more adventurous (read: crazy) Fiero drivers. They say its less trouble that a super charger by half, or rather they say they it is on their message boards.

[hayesperform...]

Hey,

You can ask me ANY question about the 3.4 DOHC, I know these inside & out and have Built even a wild N/A version. You CAN get a lot of punch out of these!!!!

Regards,
David

[GeorgesBlazah]

Originally Posted by bouda

You know you can turbo just about anything. Not saying it'd be easy.

@Tom3 3.4 dohc in a shortbed S10 you say, hmm. Nah, I don't have that kinda money.

3.4s were a pretty common swap for 1st gen s10s, bolts right into a 2.8 truck IIRC.

[newdude]

Originally Posted by 95MonteCarlo

There are some of you who may read this and ask, why is this guy working on such an odd ball engine. The reason is that this motor is an odd ball and there is so much untapped potential of this motor. From the reasearch I have done online, the tech used to develop the 3.4 went on to build the 4.6 northstar.

Even if this info turned out to be bogus, this thing is a monster waiting to be woken up and unleashed. They are finicky, but when mine was in top form I could keep up with mustangs, camaros and imports in my hometown feared my approach. I dont want to put it perfectly back to stock.

The people who love these cars and these motors know they are on the outside looking in. So I know its a chalenge, and thats one of the reasons Im doing this.

I recall reading somewhere that the Lotus developed LT5 from the Corvette ZR-1 was evolved into the Northstar. I could be wrong though.

[hayesperform...]

The biggest factor with any DOHC engine is that they are expensive to play with when building them up.

Parts ARE NOT CHEAP!

BUT,

You can get a ton of power out of them and I find they respond much better then OHV engines when adding a turbo & intercooler set up.
Thats mainly just because a DOHC engine design does allow more air in and exhaust out....

IF you are going to build a 3.4 DOHC you need the 3.4 DOHC Kent Moore tool kit.

Just watch for one on E-bay, etc

[BigAls87Z28]

http://www.denlorstools.com/home/dt1...-_j-38614.html

Had to look that up.

I would first go with the traditional ways of increasing power such as having the heads ported for flow, clean up and port match intake.
I dont belive anyone makes a set of headers for it, but one with enough time, money, and a good welder could make himself a set.


And no, the LT5 was not the father of the Northstar. LT5 is one of thoes engines that will go into GM's history books as just one crazy engine.

[hayesperform...]

I have custom ceramic coated mandrel-bent headers on one of my 3.4 DOHC's

Its crazy the difference headers make on these engine's.

With my set up, I gained 20hp, which was more then I thought I'd get.

There for the 96-97 3.4 DOHC head design with 1 3/4" primaries tapered to match the factory oval exhaust ports, v-band clamps (a.k.a. aircraft exhaust clamps), 3-1 collectors, and made with laser-cut flanges...

If I could get the "Manage Attachments" to work for me I'd post some pics.