Ok so I have searched and searched and read and read, my firebird has the 2.8l and I have already bought a 3.4l engine with decent mileage I have headr it run and everything runs great! My delima is that I cant decide whether I want to do the 3.4/3x00 swap or just stick all my 2.8 stuff on there. If I do stick with the 2.8 intake and stuff should I get it ported and polished along with the heads? I want to breach the 200hp mark someone please help Im not sure if I am capable of the 3.4/3x00 swap thanks

 

The top-end FWD swap is not simple by any means. You'll need skills in fabrication.

 

200 out of an iron head 3.4 is possible. Work the intake and heads a little, cam, and some 3.4 DOHC pistons should put you up around 200.

 

Ok awesome so would gasket matching be enough or can I go a little more drastic? Also I have the pacesetter headers so that should help right?

 

If your going to swap out pistons, might as well use the 3400 top end and pistons. With a 3.4 it's not that difficult a process to build a hybrid in comparison to a 3.1 or 2.8.

 

Are you talking about for the average 'i can't figure out my vacuum lines' owner, or the average 'i just pulled and dropped a new motor this weekend' owner?

 

You don't really need to fabricate anything (especially since you have a 3.4), you just need to slot the exhaust bolt holes, clearance the front cover a little and wire up a dis coil. Everything else should pretty much bolt-together. Anyone that can't figure out their vac lines probably shouldn't be under the hood anyway.

 

If it's really as simple as that, then why aren't more people doing it? So far, we've got grimm and firstfirebird(who seems to be doing a lot of bracket work).

 

u need to modify brackets for the accsories and make a new alt bracket,not to mention what u have to do with the ecm to run the dis

 

It takes a hand drill and bit to modify the brackets - that alt bracket you saw was an experiment. The ECM controld the DIS just fine the way it is - the same 5v signal gets sent to the ICM (DIS) ans the HEI dizzy does. It's a matter of swapping 3 wires, adding 1, and using the CPS sensor wire from a 3.4.

All the 3.1 accy brackets are on my engine and shown with close up pics to show how easy...




Hole enlarged to 1/2" from 5/16", a hand drill will follow the hole...



again 1/2" drill in the A/C bracket (if so equiped)...



one more hole opened up to 1/2" for the P/S...



The only custom item it turns out I'll be making is the coolant neck adapter and that's only because I did use the stock accy mounting and locations...



Oh and we found a TB that is 65mm to match the 3500 plenum. It only requires an adapter plate (available soon) and plugs directly into the existing harness. If a 3400 UIM is used, then that stock TB is a good alternative.

The final hurdle is the TB cable and tranny tv cable and that can be done one of a few ways. One is if you have a manual tranny, just use a 1996-2002 Vortech cble from a full size GM truck (unconfirmed that the tv cable is also a direct fit), or using a throttle box from a FWD.

Since many 3.4 4thgen fbodies have done a 3400 swap without tuning (no tuning for OBD1.5) I would have to say that the ECM in our cars will do the same - in fact the only time there even have been codes thrown is when an aftermarket cam was used.

To the comment about the mechanic that doesn't know what vac lines are, of course not - one who can not change a tire certainly won't be able to handle even a cam install or porting heads etc, but if they can remove and replace critical items such as heads, the hybrid swap isn't much more involved - it's all a matter of knowing what parts will work with what - why do you think i keep repeating all the discoveries and sharing them with everyone. Maybe someone out ther with the ambition and knowledge will follow suit.

 

Ok im not as ignorant as the person who cant determine where his vacuume lines go, and I can rebuild an engine. My problem is I get confused when people start talking about $59 codes or whatever. If all thats needed is some wiring, relocation with some of the acc mounts, and the tv cable im pretty sure i can handle that as long as there is someone to guide me along the way by telling me what parts are compatible and such. Ill read more up on using the 3400 topend or 3500 whichever seems to work best with the 3.4 because i would really like to do this swap. This is my daily driver but my license is suspended till september (**** police officers )so I got a couple of months to do this. firstfirebird is there any way you could give me a list of what ill want to use off the 3.4 and what ill need to find for the topend
2.8: sensors, acc., oil pan, ect.????
3.4: block, flywheel, ect.????
3x00: pistons, heads, intake, ect.????

 

I'm doing a 3.4/3400 hybrid myself right now, I just haven't announced it. I think people still haven't got over the stigma of assembling a hybrid. It takes a little know-how and some modifications to work, but anyone that's assembled an engine before shouldn't have a problem. Here's a list of what I needed (note that I used a roller cam and a few different items).

3.4 v6 short block (including timing cover, water pump, oil pan, flex plate & sensors)
3400 heads (including rockers, bolts & hardware)
3400 intake manifold (including sensors, fuel rails & throttle. Fabricated mine)
Large dish 3400 pistons (from '99 olds alero)
3400 pushrods (use early 3.1 cavalier pushrods w/ 3.4 cam)
3.4 DIS coil pack
8mm plug wires
Spark plugs
Oil pump
Cloyes timing chain
Clevite main, cam & rod bearings
Gasket set (.06" head)
Piston rings
Headers
Custom cam (stock 3.4 cam can be used)
Roller lifters & antirotation bars (3.4 lifters can be used)
21# injectors (need to reprogram ecm for 21# injectors, otherwise stock is fine)

Did I miss anything?

 

ahh i was under the impression u had to use that custom alt bracket

 

i'm in the process of my 2nd one the 1st didn't last 1 day but the 3.4 timing cover has a smaller spout for the lower radiator hose, or smaller than my 92 3.1 had might need to check yours also.

 

The 3.1 and 2.8 timing cover bolts just fine to the 3.4 block. The only time you will see a problem is using the RWD timing cover's on a FWD block. The RWD block has an extra water passage and the RWD cover need a hole welded (or tapped/capped) to work.

There is also no coolant sensor on the 3400 heads, so the coolant sensor in the block has to be replaced with a three wire to send two signals - one to the ECM and the other to the guage. If 3500 heads are used there is a coolant sensor bung, but the threads are the wrong size and either you need to use the same 3 wire sensor, or re-drill/tap the bung for the iron head sensor to be used.
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No, I was just looking for ways to clear up room. Since I did use the 3.1 alt bracket and tensioner, I will have to mount my TB up-side down (for the 65mm TB I found anyways).

 

Be sure to use the requisite pan/timing cover as well, the 3.4 cover won't bolt to the 2.8 pan.

 

the 3.4 timing cover will bolt up fine but the 3.4 has a smaller in diameter radiator hose on them than the 3.1. or the one I had did.

 

So as far as the sensors like the TPS, and IAC valve ect do you have to cut and splice your wiring harness to work with the new sensors on the 3400 intake manifold as well as other various plugs? Sorry if im asking dumb questions I just wanna make sure i understand everything before I go buying parts and such. Also will the pacesetter headers for the 2.8/3.1 bolt up to the fwd heads or is it a different bolt pattern?

 

Really?! Are you sure you aren't talking about the pre-'86 pans? AFAIK the 2.8 MPFI's are the same.

 

the sensors has the same plug ins you will have to make a adapter for the throttle cable and slot the bolt bolt holes in your headers but they will work. If you can rig something you should be able to do it

 

Here's my pan. Note the angle on the front of the pan lip.


And here's a 3.4 pan.

 

Is that the v-belt setup? All the serp belt cars I've seen had the same pan as the 3.4 and 3.1. That's why I asked if it were pre-'86.

 

Should've read through waht you said instead of hitting the post button, it's an '85. Many parts differ from the '85 and '86-up 2.8's, which is why I opted to use the 3.4 cover/pan/pump ect.

 

Ok so let me get this straight you used the 3.4 timing cover with matching 3.4 oil pan because you ran into problems using you pre 86 2.8 stuff right? I have a 2.8 w/ v belts out of an 86, would this mean I could use the 2.8 stuff? Im sure if I had the parts apart and fitted them I would be able to see which will work best, but I havnt had time to tear apart the engines so im just gathering info.

 

Ignore my brain fart, your parts will work. Just saying you can't mix-n-match certain parts.

 

Sweet looks like someone saw my post and im getting an awesome deal on some rebuilt 3400 heads and complete 3400 intake along with gaskets Looking forward to getting them in the next couple of weeks Ill try to get a digital camera so I can keep everyone updated on th 3.4/3400 swap

 

Also ok so ive read to use the 3400 pistons out of like a 99 alero this should give me 10:1 cr, which is ok for pump gas right? Also what kind of tuning issues will i be running into? Which setups seem to work best? (MS os tuning stock ecm) I really only have the basic mechanic skills so this stuff tends to get a little confusing but im learning...... slowly lol

 

You'll get 9.8:1 cr w/ .06" head gaskets. Pump gas is fine. Like I said in the pm you really need to tune it to get what you want out of it. Take a look at this.

 

I think i have read that thread before but no matter how many time I look at it I get confused lol. I guess I need to look up some terms and read up some more on tuning, but right now I need to get the motor in the car then i can look into tuning and possibly boosting. Just need a good foundation, I think this setup is gonna be tons better that the lil 2.8