I advise all people to read ked85's swap tech artical first. Then if your still confused, read mine.

Mr Ked85 (karl) was the leading person on this board to teach people how to do this swap. Since he has now in a better place and cant be with us, I think I am possibly the next person with the most knowledge of this.

So, if the mods want to make this a stick, go for it. Any of you swappers that have done this, see I forgot something, post it. If you want to do the swap and STILL have questions after reading both, post it.

 

First, we have decided there are 3 different type of swaps.
Version 1: full stealth smog police
Version 2: 2.8/3.1 top, with 3.4 bottom and accessorys (project85)
Version 3: Full 3.4 SFI swap (includes ecm, accssorys, wireharness)

Included here is for version 1. I have done the version 3, but it is not worth it on a mpfi engine.

A: pre pulling your current engine
A1: Get your engine
A2: Before you do anything else, if you have a fan sensor in the rear of your right head (2.8guys), do what you feel is safe to get the plug out of that spot on your 3.4
A3: stop by your local parts store and get
A3-1. Full rebuild gasket set for your current desgin engine (me it was 91 3.1)
A3-2. Oil mount gasket (from gm dealer)
A3-3. Tube of clear silicone
A3-4. Injector o rings
A3-5. Timing chain
A3-6. 3.4 spark plugs (r43tsk)
A3-7. t-stat
A3-8. oil and oil filter
A3-9. any questionable parts that you don’t trust the intergity of (belts, alt, coil, sp wires, water pump)
A3-10. Freeze plugs for the 3.4 if you want too
A3-11. Performance cam shaft if you want too
A3-12. New oil pump if you want too

A4: rotate your 3.4 to piston 1 top dead center
A5: pull the fuel rail out of your 3.4, remove the injectors, put them in a ziplock bag and put them in a safe place, you need these.
A6: pull all engine accessorys off the 3.4, the y-intake, the coils, the valve covers, lower intake, crank pully, balancer, water pump, timing cover, exhaust manifolds, motor mounts, starter, oil pan, distrib plug/oil pump drive. Put the balancer with your injectors as you need this. Rest, push off to the side, you don’t need it any more. This should leave you with a block, heads, crank, connecting rods, pistons, cam, timing chain, lifters, pushrods, rockers.
A7: install your new timing chain (and cam shaft if choosen)
A8: on the right side, you have a knock sensor, it needs to be moved down to a different plug down by where the starter was. Swap the sensor and screw in plug around.
A9: you have 2 sensors in the 3.4 that the 2.8/3.1 doesn’t use. You can remove them and fill with new freeze plugs if you wish. Most just leave them in the engine.
A10: install all freeze plugs if you are going that route.
A11: flywheel/flexplate. If your 3.4 came with the proper fly/flex, leave it on. If not, we must do something about it. It is advised against to use your 2.8 one. 3.1 guys can re-use the one on the engine. This is because most 2.8’s are exteranlly balanced, where 3.1 and 3.4 are internal. So, 2.8 guys, go get a 3.1 or 3.4 fly/flexplate.

This should leave you with a 3.4 that’s ready for the 2.8/3.1 goodies.

B: Pulling Your engine
B1: before you pull your engine, pull the distrib out, drain all fluids. Advise pulling most of your engine accssorys off as sometimes these things get bumped and damaged in this process. Label any wire and connection so that you will know what it goes to when you drop the new one back in.
B2: pull the engine
B3: Clean your engine bay, check your radiator, any hoses, wiring, and rubber motor mounts. Now is the time to replace it if needed.

C: Swaping parts from current engine to new engine.
C1: start with the timing chain cover, put it on the new engine with water pump, 3.4 balancer, crank pully, wp pully.
C2: Bring your 2.8/3.1 oil pan over, install with new gasket. (oil pump if you decided to do that)
C3: Bring your exhaust manifolds over. Reason for this is that the 3.4 ones have o2 sensor holes, and possibly not your proper smog holes.
C4: Bring your oil filter mount over.
C5: Bring your motor mount brackets over.
C6: Bring your base intake over, and set/adjust your rockers per the manual (if no manual, please search my user name, ALONG time ago I re-typed it strait from the GM manual).
C7: install new t-stat and goose neck.
C8: Install clutch or you manual guys

D: Install new engine.
D1: Put your new engine in, carefully watching that you don’t set it on any wires or hoses.
D2: Now re-connect your exhaust FIRST, you may have to rock, move wiggle engine around to make it bolt up
D3: Bolt it to your transmission, then the motor mounts and re-connect everything under the car.

E: Finish swapping accssorys over
E1: Now re-install your 2.8/3.1 power steering, alt, ac, smog
E2: install the 3.4 injectors into your existing 2.8/3.1 fuel rail
E3: install the disributor into the block per the manual. You may have to take needle nose and rotate the oil pump shaft.
E3: Install everything else…..valve covers, coil, sp wires, new 3.4 plugs, middle intake, fuel rail, upper intake, belt, etc.
E4: 2.8 guys, don’t forget about that fan sensor in the right head.
E5: make sure you did get a good ground on the back of the heads, and the wire from the battery.
E6: put on new oil filter and fill with fluids.

You now should be good to start it up and set timing and install fluids. May have to re-adjust your detent cable on the automatics.

 

Thanks Dale. It's always great to see that people are willing to take the time out of their busy schedules to do things like this to help others out. It is very much appreciated.

 

Oh, out of curiosity though, what is that plug in the head for the 2.8 motors? Is it just a bolt that plugs the hole for the coolant sensor and you just unbolt it and put the sensor in? It seems like it's a plug that takes a lot of effort to take out though.

 

2 plugs on a 2.8 you have to deal with, 1 on a 3.1.


2.8.
Plug in right rear head. The heads are designed to fit left or right. It is an "innie" plug, thats the worst freakin thing to ever remove.

plug on right side of block, down low, rear by the starter. Just a wrech will remove this one. Put some silicone or tufflon thread locker on it before you put it back in the block on the right side, up high, front.


3.1
plug on right side of block, down low, rear by the starter. Just a wrech will remove this one. Put some silicone or tufflon thread locker on it before you put it back in the block on the right side, up high, front.

 

ooohh.....damn....those innie plugs are the WORST to deal with!!

 

One question. Do the cars seem more powerful after the swap? I did the 3.4 swap on my 85 s-10 truck a couple years ago and the results were very disappointing. Maybe it was just the gearing on the truck I don't know.

 

The 3.4 is not a performance swap.

 

I did a full 3.4 sfi swap into my s10. The main difference is that the cam in the 3.4 is more for top end, where the one that came in the s10 is for torque. You should have swapped cams in the truck for more of a truck cam.


I would say I did feel a bit of power difference in the car, but I had more peice of mind knowing I had an engine under the hood with 1/4 the miles, and no clunking noise.

 

but you do gain some torque and horsepower differences especially when compared to a 2.8 right?

 

F-body
2.8 Carb LC1 82-84 107@4800/145@2100 8.5:1 comp 3.50 borex3.00 stroke
2.8 MPFI LB8 85-89 135@5100/165@3900 8.9:1 comp 3.50 borex3.00 stroke
3.1 MPFI LH0 90-92 140@4400/185@3600 8.5:1 comp 3.50 borex3.31 stroke
3.4 SFI L32 93-95 160@4600/200@3600 9.0:1 comp 3.62 borex3.31 stroke


S10
2.8 carb LR2 vin "b" 110@4800/148@2000 8.5:1 comp (83-85)
2.8 TBI LL2 vin "r"125@4800/150@2200 8.5:1 comp (86-88)
2.8 TBI LL2 vin "r" 125@4800/150@2200 8.9:1 comp (89-93)

Fiero
2.8 MPFI 85-89 ... 140@??/??@???? 8.9:1 comp


Edited for typos.
edit2 for more info
edit3 for even more info
edit4, correction on 3.4 compression

 

160 vs. 135? yup...I guess there must be a difference!

 

As I recall the 3.4 is 160hp and 194ft-lbs. tq at the crank.


I felt a significant gain in power. It was a lot "Snappier" it would throw you head back faster and harder but it didn't last long.

I also had some exaust and intake work done. Just really minor intake work. I had a Flowmaster Muffler, no Cat and it was 1/4in. Larger pipes than stock

 

87 camaro, your correct. 194 to 200. Will correct my post.

Anyone know the tq rating of a 2.8?

 

Don't quote me on this. But I am pretty sure that the 2.8 hade 160ft-lbs and the 3.1 had 180ft-lbs and as I said earlier the 3.4 194ft-lbs

 

do i use the harmonic balancer from the 2.8 0n the 3.4 or use the 3.4 balancer?

 

3.4. iirc it still had the big timing mark the width of the balancer

 

correct. It still did have a timing mark.

 

All the HP/torque specs for the cars is listed in the tech central section of the home page. Click on tech data

 

thanks, edited

 

Pictures from last night...beginging the swap

 

 

so, i unbolted the lower intake, but it wont come all the way off, it seems to be hanging onto one of the studs in the left cyl. head. I cant budge the manifold further thanlike an 1/8" apart from the block/heads. any tips?

 

Putty knife and pry the intake up. Dont use a screw driver, you may gouge the sealing surface.

You can also carefully remove the studs with a very small socket, or vise grips(watch the threads). Then intake should move more freely.

 

TTT cause I added more info, and have more peeps asking about the swap.

 

u gotta take it off equally on each side so one side doesn't come off b4 the other. basically lift it straight up not on the side u will need to probably use a small pry bar or a flat head screw driver

 

Thanks Dale you answered alot of my questions. But I still have a few if you guys could be so great to give me some insite. Let me start off by saying I have done searches for this to no avail. I have an 86 camaro with a 2.8 which is not running, and I have recently acquired a 3.4 from a 94 camaro with transmission both cars are automatics. Also i do not have a complete wiring harness or a computer for the 3.4.

1. I would like to know if I can just pull my old motor and trans and install the 3.4 and trans in its place with a new computer.

2. If not what would be my best option to get my car back on the road.

 

Leave your 3.1 ecm in the car, you DO NOT do anything with the ecm or any harness work.

The 4l60e or whatever came behind the 3.4 will not work in your car w/o modding the harness/ecm. Leave your 700r4 or have it rebuilt if wish.

 

Hey. Have you read the original thread here?

https://www.thirdgen.org/forums/v6/6...-do-3-4-a.html

Edit.....Well darn, ya beat me to it Dale

 

for the work you have to do to swap the harness and ECM to make the SFI work, its not worth the gains. and there might be some numbers posted somewhere, but i dont know where, but the 3.4 intake isnt really an upgrade from the 2.8/3.1 intake. its actually worse for porting applications. dale or project would be able to tell us if its worth swapping everything over to SFI though.

and id rather have a dist, you control the timing, not the computer. just disconnect the EST and turn the dizzy.

 

hey cool guys thanks for the help and yes I have read the original post but still had the few ?'s about the tranny and ecm I will be starting the swap in a few weeks once me and my dad get a few cars out of the shop.

 

yeah, teh 700 tranny has like, 4 wire iirc, the 4L60E is around 13~16.

 

the gasket needed when swapping over the 2.8 oil filter adaptor to the 3.4 block is p/n: 12337894 (dealership)

 

Why isn't this stickie yet?

 

145@2100, thats what my 2.8L has.

 

another thing that sucks is this thread is now so old, I cant go up and edit typos, and something I noticed was forgotten.

 

its probably not a sticky because the same questions would get posted over and over again anyways, lol.

 

hey guys im gearing up to do a 2.8 - 3.4 swap. just need to get the engine first. any ideas where to find one? or a price on them?

 

Alright. Sorry to revive this thread.
I've read all of the above and I got that I *have* to use a 3.1 or 3.4 flywheel.

Now, I'm wondering if I HAVE to use the 3.1/3.4 harmonic balancer.
I'm asking because if I do, I'll have to buy one or get one from a junkyard as I only started with the 3.4l block itself.

So far the only 3.4l stuff going on the 3.4l block are:
spark plugs
flywheel
fuel injectors

Is this right?
My project is coming together and I can't afford *any* money misspent.

Thank you.

 

Some of the very very late 2.8's have neutral balanced balancers, but your better safe using a 3.1/3.4.


Here is the info behind this.

Back in the old days, the flex/fly, crank, and balancer were all balanced in unison and if you had to replace one of them, it had to be balanced with all the other parts.

Depending upon the motor, depends on the year where all this stuff went to self balanced. Meaning you could replace one, and not worry about the others.

For the 6/60 motors, this was the late 80's.

 

Hi Dale, thanks for the great article, how is your swaped engine doing?
i have question, can you give me the link to webpage that is selling "Full rebuild gasket set for your current desgin engine" mine is 3.1 like yours, my engine block is cracked that is why i am going to do swap. btw my camaro is one and only thirdgen camaro in my country! i finnaly found engine from 1994 3.4 camaro, now i need some new parts like gasket set and i am ready to go!
it would be great if you could advise me gasket set of which brand is better.
thanks

 

http://www.advanceautoparts.com/

http://www.autozone.com/autozone/

http://www.oreillyauto.com/site/c/home.oap

http://www.napaonline.com/


these are the 4 main stores around me.

 

sorry about bringing this back to life, but I have the 4L60E tranny in my 1991 FB Vert. If I do this swap, do i need to do anything with the transmission?

thanks for the help guys.

 

Aslong as your ecm is controlling it now, then it should control it later.

I would make sure the torque converter is good, change the fluids if you havent lately. After swap is done, you may want think about a shift kit??

 

Since when does a 91 have a 4l60E? The electronic controls (other than the torque converter clutch) were introduced in 1994 to the 700R4 (which was renamed the 4L60 in 92 due to a Fed regulation). Unless it was swapped in with a custom ECM or external trans controller (more than likely an external controller as the available 94-95 ECMs were not programmable), it's not a 4L60E, which has more than 5 wires going to it (2 for VSS and 3 for the TCC and gear switch).

I'd do the shift kit and a Vette 2-3 servo kit before the trans gets mated to the engine, just to freshen things up a bit. Although, if the fluid that's in it looks burnt, you may end up with a clutch pack failure in the future (even without the shift kit and new servo due to increased torque load from the bigger engine). Also, think about an aftermarket converter as well.

 

Thanks guys. I looked at my service manual for my '91 firebird and it shows the Hydramatic 4L60 tranny in it. Is this the same as the 4L60E. I agree with the shift kit. I have been bouncing back and forth lately on putting a 350 in it or modding the 3.1/swap 3.4. You have sold me on the 3.4 upgrade. I have read around and see that with proper perf. mods you can get pretty good HP out of it.

Are there any good threads you recommend to build up a 3.4 block an make is nice on a light budget.

thanks for all your help.

 

If the trans was a 4L60E, the service manual would show a lot more solenoids in the wiring locations diagrams than just the 3rd and 4th gear switches and the torque converter clutch solenoid. Again, the 4L60E wasn't used until 1994 with the 3.4 4th gen.

 

Thanks Maverick...
So when I do this swap will I be able to use the heads off the 3.4 or do i need to bring my 3.1 heads over. The reason I ask is i think I have a valve seal leak on my 3.1. Thanks again for the info. Also has there been any numbers posted on which is a better intake to use the 3.1 or the 3.4. I am very new to the engine swap and the 3rd gen cars, so I just want to do this right. My eventual goal is to do a single or twin turbo on the car.

thanks

 

The only parts you need to swap from the 3.1 are the fuel rail and upper plenum (maybe the intake manifold to heater core pipe), and the accessory brackets and accessories, along with any possible sensors that don't match. The fuel injectors and everything below stay with the 3.4. Do a water pump and as many gaskets as you can while the engine is out.

 

So I can use the entire intake off the 3.4? I saw in another thread here where the intake had to be notched out for the distributor to fit. Maybe I'm mistaken as I am pretty new to this. Is it pretty easy to do a distributorless ignition on this car too. I just heard someone mention the 3.4 makes it easier to do this.

You are helping a lot. I have found the motor. 3.4 out of a 95 camaro for $350. Only downside is it has 101k on it.