I'm picking up a complete 3.4 tomrorow for my sisters car. Her 3.1 is blown.

I read the swap boogie, along with a few other posts and I see some conflicting reports. I read through a bunch of threads and it seems some people did one thing, some did another.

I have some questions here.

1) DO I have to remove and change the oil pan?
2) Do I have to remove and change the manifolds?
3) Do I have to remove and change all the accessories,
and if they stay, does things like power steering lines need
to be changed? Whats the scoop?

I know I need to change at minimal: motor mounts, intake manifold, move a sensor, remove the dist plug that spins the oil pump.

Thanks!

-- Joe

 

if there is a 3.1 in there now i dont beleive that you have to mover that sensor for the fan...

you can use the 3.4 oil pan, you are using the 3.4 block, makes sense right

manifolds dont really matter, only problem i can see with the 3.4 manifolds is they may not line up just right with your existing exhust

the accesories i was kinda confused about as well.... someone clarify that

 

Well the exaust is the question. Do the manifolds line up or will I have to change them? Ive had bad luck in the past with the manifolds on 2.8s.. Either pulling out the threads in the head, or outright breaking.

-- Joe

 

I left the 3.4 pan on mine, it DID hit the cross over pipe. Same engine in someone elses car didnt. I advise to for best case.

Manifolds will bolt up to existing y-pipe. You will have to leave old O2 sensors in them, or swap them for perfect stealth swap. 50/50 here.

Swap all engine accessorys. The 3.4 power steering bracket puts it in different posession, along with alt too.

Install new timing chain while your at it That is a weakness of these engines.

 

So basicly. Strip it down to a long block, and rebolt all the 3.1 accessories? That kinda stinks. Oh well.

The reason I wanted to use the 3.4 pan was cuz the 3.1 pan is crushed a but but, I guess i'll hit it back out with a hammer..

Thanks for the info

-- Joe

 

so can you reposistion the alt and power stearing to use the 3.4 brackets(steath isnt a huge concern to me seeing as most wont notice unless they have a v6 camaro) im sure the alternator is easy to move but any help on the power steering...

 

i used the 3.4 pan and had no problems. i also used the 3.4 p/s pump. just removed it from the bracket and used the 2.8 bracket. the pump itself is the same. so if you have a lot of miles on yours and your 3.4 doesnt, there ya go, lower mileage pump. i used the 3.4 manifolds too, i just took two o2 sensors, broke em off, and brazed them shut on the tops to plug those, till i got headers. good idea to get new motor mounts while youve got it out, i wish i had cause i think i need em now, oops.

 

Yep, sorry. But you want your sister safe right?

Dave is correct, the ps pump is the same, it is the bracket that is different.

I belive (check this for yourself) the 3.4 lower section of the intake could stay on, just swap upper.

 

Whats the safe issue?

I have the motor in the back of my truck right now. Not even sure why you'd have to swap the upper? does it hit the distributor or something?

the manifolds look close, same with pan but I wont know for sure. I think the rear main is leaking.. gotta take the flywheel off and check to be sure. Might also need a gasket on the cam thrust plate..

Overall it looks similar. Looks like just swap the serp setup from the 3.1, and see whatever else fits ?

-- Joe

 

The 3.4 plenum won't clear a distributor IIRC. Remove 3.4 intake, bolt on 3.1 intake with 3.4 fuel injectors. Injectors are critical with Speed Density setup.

3.4 exhaust manifolds bolt to 2.8/3.1 Y-pipe

3.4 oil pan *should* clear.

Might need to replace 3.4 timing cover with 3.1 timing cover to get a timing mark.

 

Can you wake up on ircd? I'd like to talk to you about this. Been looking for you for a few days.

-- Joe

 

yes you do need to use your old timing cover for timing marks.

 

safe that its done right and reliable the first time.

yes, timing cover has to swap.

3.4 upper intake wont clear distrib, and the TB/neck points to much downward.

 

so really all that needs to be 3.1 is the upper intake and tb....id like to keep all the 3.4 stuff together if at all possible...3.4 heads manifold etc.....i like the 3.4 brackets better than the 3.1s thats why i wondered if i could use the alt and ps brackets(they would look better powder coated )

 

pills, thats the way project85 did his 3.4. He used the 3.4 accessorys, oil pan, injectors, and then the 2.8 intake, ecm.

When I got the engine from him, I pulled the accessorys off and put my 3.1's and my 3.1 intake. I left the oil pan (with new gasket). It hit my cross pipe, but I lived with it tell my headers got installed.

 

yeah i dunno i just like the way it looks better, its a subtle change but either way at least i have the option to use either as they both do work with some massaging i cant wait for my block to get powder coated so i can start putting it together finally....heads are almost done being coated now(check my 3.1 to 3.4 swap thread) they look pretty bling

 

forgot the picture woops

 

On Redraif's 3.4 swap (from 2.8), we used the 3.4 oil pan with no issues. We did swap on the timing cover from the 2.8 (Though you could just add a timing pointer), and used the complete intake manifold from the 2.8 (ported), though the base is the same. We also used the heads from the 2.8 (not necessary, but they were already ported as well). We used all the accessories from the 2.8, since some of the 3.4 stuff was missing, though we did eventually install the 3.4 PS pump (with the 2.8 pulley, its different...not sure about 3.1 apps though). We also used the 2.8 exhaust manifolds, since they were ported and coated.

 

Exhaust manifolds
Leave them alone as they bolt right back up to the original vehicle exhaust pipe
Induction system
Remove from original vehicle engine & reinstall onto the 3.4 LONG BLOCK, complete, no shortcuts. Add the 3.4 injectors to the original vehicle fuel rail (they slip right in) and also open up your old vehicle Fuel Pressre regulator. Add the fresh innerds of the 3.4 FPR for best results (fresh rubber is important in the pressure regualtor)
Ignition system
Remove the original vehicle ignition system & replace onto the 3.4 long block.
Front timing cover/oil pan
This part leads to some confusion
IN END
you still need remove the 3.4 timing cover to replace the chain AND TENSIONER AND ADD balancer repair sleeve to the 3.4 balancer.
It is up to you which timing cover to reuse.
ME I went for the dummy system which meant remove the original vehicle timing cover & oil pan & reinstall onto the 3.4.
That way you are 100% guaranteed that all original vehicle front mounted accessories will fit with NO question.
IF at all possible add the 3.4 frame mounts from other vehicle as they are identical to the original vehicle mounts. Use the original vehicle motor mounts, this mates perfectly.
Score the 3.4 power steering pump as it is newer. This PS pump bolts right back to the original vehicle PS bracketry. Score the 3.4 starter motor as it is also newer.
Replace any sensor you can now. I must tear my upper apart to replace a cold ssensor that has gone bad, wish at that time I knew better, oh well.
Do this job quickly?
Take your time & make every gasket seal superb in sealing.
Yes do change the cam cover in rear along with the rear main seal. Both GM deler items.
You will have no regrets in this powerplant choice!
Hoping your tranny is in good shape!
In end, strip the 3.4 block down to long block & rebuild using as much necessary original vehicle stuff as necessary for long term no repair daily driving. I built one engine side at a time & then turned to next side & continued my rebuild of the 3.4 long block to go under a vehicle hood. I've gone about 20,000 plus miles since my swap many years ago & love every mile I spent doing it right & hated every learning error I have to redo! Like lately needing to redo a cold sensor on the intake manifold. That is a lousy $6-$8 part I must replace now....
Don't forget to do the oil filter housing swap, too! Use original vehicle one on the 3.4 block!
ALWAYS ADD THOSE NEW O RINGS wherever & whenever possible!
Take your time do it right! And leak free! for all those future smiles!

 

Put the 3.4 on the stand. Started taking all the stuff off that was not needed.

I'm leaving the intake baseplate on. It's the same as the 3.1, with only a small hole in the front for the cam sensor wiring. Plenum + 3.1 fuel rail should bolt right in it seems.

As far as timing. water pump, etc is concerned, if they're not broke i'm not fixing thing right now. (If they fail in the future, its just as easy to do them on my lift from underneath).

I should be able to reproduce the timing tab by removing the crank sensor bracket.

In respect to a "swap" vs a swap + rebuild, which is what most of the threads really are, (swapping a motor, then replacing 60% of the parts isnt really just a swap anymore)
this seems pretty straight forward. If the accessories + plenum worked, it woulda been a direct swap.

-- Joe

 

motor..

 

To Me, the idea of the swap is just swapping parts back and forth betwen the two long blocks to reproduce what was originally under the hood, vehicle new.

My platform 1985 2.8s, things were different than in the later years & what can stay on (3.4) & swap one day.
As I said, I also played the dummy system, swapping what came originally (1985 2.8 stuff) to will be (the 3.4).
YET each is a custom swap and each person does their own tweeks.
Hoping yours works out for the best.

 

The only reason i'm doing this is because we couldn't find a 3.1 locally. Trust me, I'd rather have just dropped another complete motor in and fired it up.. Spending 2 hours swapping accessories + plenum from one motor to another is not how I wanna spend my free time.

the 2.8 - 3.4 would be harder i'm sure. I have a 86 2.8 in my shop with the vbent setup and things are just different. Plus maf, and all.

-- Joe

 

sounds like you now see most of what we said now that its in your hands.

Only thing I disagree with you on is the timing cover/waterpump, and timing chain.

We cant stress enough that the weak spot is the timing chain. They are toast at 50-60k. Plus you do need a timing mark to set the timing.

Otherwise off to a good start.

not mentioned. The knock sensor will need to be moved from right side, upper right... to..... right side, lower left down by starter. Then plug the hole it just came from.

 

Leave the sensor there & not worry about a hole.

As for the timing tab... I transferred the one from the 2.8 to the 3.4 in an approx location. The "tube" thing was off, but I was able to get two of the teeth where they needed to be.

 

In all honesty,
The timing chain, water pump, tensioner are so necessary to replace.
Now,
while it's out in the open.

 

I could be wrong, But I've heard that my 86 2.8 doesnt have a knock sensor, is that right? I really wanna do this 3.4 swap but it wont be for a while. I'm also goin to turbo while I'm at it :evil: But probally need a V8 T5 to handle all that power lol

 

If your really looking to make "power" then go with a v8 swap. I'm doing the 3.4 because I couldn't find a 3.1 & its a girls daily driver.

Even the most tricked out 2.8-3.4 v6, compared to my 600hp formula is just laughable. But for a 17 year old girl, who needs to get back and forth from work and college, a v6 is ideal.

-- Joe

 

The 3.4 set up under the hood provides a wonderful powerplant, full of power and makes the car much more drivable. Wait until ya start to use the Air Conditioning, plenty of available engine power for that option.
Plus ya reuse so many of your original vehicle parts, everything tends to fit with minimal fuss, it's a win-win swap situation.
Enjoy doing the 2.8->3.4 long block swap boogie!

 

Like I said, for a 17 year old full-time student, its great! Should be reliable.

-- Joe

 

Wait until ya feel the torque. It's such a blast this engine in this car.
I do understand tho it is laughable compared to 600+ HP.
The girl will be most pleased.

 

Screw that. I drive plenty of V8s. I have a 5.8 in my truck. I want a 3.4 Turbo

 

Alot of the fun of this swap is making your own creation.
Who says ya can't turbo the final product!
It's up to your talents & wallet.

 

Yeah a 17 year old girl wont know the difference, and i'm sure she will think its a fast car. If she was into performance, or if it was my car i'd do a 350/T5 setup in it. But for her intended use, it made sense to just replace the v6 with a similar block.

-- Joe

 

While accomplishing this swap, you'll see & feel, in end, how great a project it is.
For the MPFI set up it's easier to start with a dead V8 ride, then upgrade to a V8.
But the car will be a real blast to drive in the end, if it's a healthy 3.4 mill. Both mine are low milage ones & still full of power.
Ya won't win every race but sure is heck of a lot more fun trying!

 

Yanked it. The a/c compressor, ps pump stayed in the car. The air + idler bracket came out with the engine, and was transfered to the 3.4.

The manifolds are different cuz of lack of air injection. I'll prolly drill and tap it, since the studs broke on the 3.1 exhaust manifold.

The 3.4 lower doesn't have a fitting for the PVC. No biggie.

The timing tab can bolt right to the 3.4 timing cover, but uses security torx. No biggie.

The water neck is the same. The collant fittings are different, but uses a quick disconnect so the 3.1 peices go right in.

The water pump has a different size inlet, but, thats no biggie.

The housings for the 3.4 and 3.1 oil filter are pretty much the same, except for the sender itself. The 3.1 housing - someone stripped the bolt.. Thats gonna be a pita tomorrow.

Took about 4 hours to yank it, and put the 3.1 stuff on the 3.4. Should take about 4 more tomorrow to get it up and running..



-- Joe

 

Boogie On!!

 

 

THe knock sensor needs to be moved to the back of the block and swapped with the plug, otherwise the motor mount wont bolt in.

The thrust plate gasket leaks, and I can't find one local. So looks like I have to order one.

Along with some bolts that needed some heat to come loose (studs on the 3.4 manifolds) and some other things. I think I've so far exceeded the amount of time it normally takes me to do a v8 job. So I've come to the conclusion that, I should have just put a 350/t5 in the car.

Once the 3.4 is done hopefully when I find a gasket (tomorrow?) the tranny will prolly blow.

The work to output ratio is not in the owners favor, so this project gets two big thumbs down from me. It will be finished, but between all the issues, running around for parts, etc. it will be roughly 10-12 hours of labor and around $400 in engine + parts.

-- Joe

 

The big problem with this project is yes the tranny blowing.
The good thing is the tranny blowing so ya can get it rebuilt (ya hope) stronger!
Torque is quite strong on this engine.
Bummed to hear your trials but it can go like that.
When I did mine I had no true coaching besides what I started with (my 2.8 under the hood). Atleast ya had some clues. But yeah every swap tends to be a bit different.
IF ya can go grab a balancer snout sleeve repair. It's $4 & really helps any leaks at timing cover area. Ask for a 2.8 3.1 sized part, they fit a 3.4 balancer perfectly.