FbodTrek

That Blows ****! Those ****** that bent mine are gonna get soooo chewed out (lord knows they won't replace it....). In what way is it different anyhow? It's bound to be the same diameter and teeth count. I got the motor tore down right now, the 3.4 intake is still on, but everything vestigial has been removed. I plan on scrubbing it down and painting the block heads tommorow. I didn't have too much time to work on it today, too busy with whiny customers. So, i won't be using the cam sensor or what? One more thing, are the mounts the same (I assume they are but....). Thanx as usual

Project: 85 2.8 bird

I just cut the wires leading to the cam & crank sensors on mine. The sensors now act as plugs that shouldn't be removed.

The difference in the flywheels are how the egine itself is balanced, internal vs external. I'll those more versed in which is which give a more detailed explanation.

Motor mounts are the same, jsut replace the 3.4 brackets w/the 2.8 ones, otherwise you will never get it to fit (properly).

KED85

Let's help.
IF ya got the 3.4 engine motor mounts, no they will not work at all.
YET if they included the engine bay frame motor mounts, on the 3.4 motor mounts, those will interchange with your 3rd gen F Body.
The flywheels are "identical" EXCEPT the 3.4 has a different weight on it. I am unaware how to make a 2.8 F-wheel into a 3.4 item. PERHAPS an experienced welder/hot rodder/engine builder can "help".
As with the 3.4 balancer, you LEAVE THAT in the engine swap. You MOUNT the 2.8 pullies on the 3.4 balancer (after you've done the new T chain & also used a 2.8/3.1/3.4 balancer snout repair sleeve).
You're getting closer.
How much fun was removing the recessed block plug in the passenger head?

LT1guy

iTrader: (1)

The balance weights are the difference, diameter and tooth count is the same. The harmonic balancer is different (for the same reason), so use the 3.4 one. You'll still have to remove it to install the 2.8 timing cover (or make a pointer, since there is no timing mark on the 3.4 cover), though. Use the Fel Pro sleeve kit as Ked mentions, its good insurance. Also, there seems to be some confusion about the oil pan...the 3.4 pan WILL work on a third gen, though it does seem slightly closer to the crossmember. We used it on Redraif's car because her original was beat up and rusty.

KED85

But to clear up.
The Oil Pan & Timing cover MUST BE of matching items.
Either original vehicle 2.8 T cover & 2.8 matching pan or the 3.4 set up.
NO mixing allowed!
This sleeve is only $4!

FbodTrek

Balancer snout? As for the flywheel, I'm gonna have to hunt for one I suppose...And, by brackets, you mean the ones fastened to the block right? Oh, one more thing, do I use the 3.4 injector harness or the 2.8 one?

Project: 85 2.8 bird

yes, the brackets that mount to the block, reuse as much of the 2.8 harness as humanly possible to avoid any snags.

The balancer snout sleeve KED's talking about is the harmonic balancer repair sleeve.

LT1guy

iTrader: (1)

Gotta disagree there Ked...Redraif's 3.4 has the 2.8 cover and the 3.4 pan, and there were no issues (leaks, fitment issues, etc).

FbodTrek

Where do I aquire this repair sleeve thing? The harmonic balancer I got is in good shape, do I still need it?

Project: 85 2.8 bird

Any ol' pars place. KED wants it replaced as cheap insurance, kinda like that sbc distributor gasket.

KED85

FOR REAL!
What year was worked that way?
I know that my 1985 stuff is early 2 piece design and the 3.4 pan would not swap to my 1985 2.8 T chain cover. So I assumed. Thanks for clearing up!
The vehicle we're chatting baout is an 1986, I recall, right? More details discovered.
On the Fuel Injectors.
Here's what ya do. Re use the ENTIRE orginal vehicle Fuel system. Replace the original vehicle 2.8 injectors with the 3.4 injectors that came with the 3.4.
They hook right back to the 2.8 fuel injector harness. The 3.4 injectors are replaced into the 2.8 fuel rail. The 3.4 injectors are the ONLY thing ya can use from the 3.4 fuel injection system.
PS when ya remove the throttle body from the original vehicle engine MPFI unit, don't disturb any cable hookups. If every cable setting was perfect before, it sure will be later on, too

Sleeves, again ask for Balancer repair sleeve for 2.8/3.1/3.4 engine, it costs four dollar & Fel Pro offers & so does Napa.
On my Blazer swap, I learned this trick.
On my Firebird swap, I have to redo this part as I have slight leak there, never did this during the swap, oh well!

FbodTrek

I'm gonna leave it alone then (a busted balancer is easy to fix anyway, assuming I kill the motor when the rubber separeates...). So.....My accessory brackets will bolt up, and I use the 2.8 harness, intake, dis, fuel rail, water pump, timing cover...am I missing anything? LOL. Really guys, I totally appreciate the help. I'll have to treat you fellas to a few rounds if you ever come to Houston! Oh yeah, will my 2.8 valve covers fit (I kinda figure they will...)? Plastic valve covers are whack.

AM91Camaro_RS

yes, the valve covers will fit. you should pick up a set of chrome ones or something....dress it up a little more.

Project: 85 2.8 bird

I used teh 3.4 drivers side valve cover on mine, I like that extra long filler neck , and had to use the 2.8 cover on the pass side. (now I have a 2.8 drivers side & 3.4 pass side cover hanging in the garage by my 400 Poncho covers ). Also, make sure the braided ground strap from the engien to firewall is in good condition.

WhiteBlaze

iTrader: (1)

Hey... I have a question... I originally swap a 3.4 into my blazer with a manual tranny... so I bought a new 3.4 flywheel from GM... well, it didn't even come close to fitting into the bell housing... it was too deep... so when you guys say that they swap over no problem, do you mean that these will work with the f body trannys, but not the Blazer version?

Thanks
Keith

Dale

iTrader: (12)

blaze, in your case since it was truck, you should have gotten one for a 93 s10 with 2.8 and t-5 (see siggy )


might want to try s-series.org, alot of help when doing mine.

FbodTrek

As far as the flywheels go....The 3.4 one has no balancing weights, is the differance that the 2.8 does? I replaced the main seal and cam plug gasket today. Gave the black a gasoline bath followed by 2 cans of brake cleaner. I'm gonna leave the 3.4 intake on the motor until I pull my 2.8, don't want anything crawling in there.....lol. By the way, nobody carries the cam plug gasket, had to cut one myself from a sheet of Mr. Gasket asbestos Gasket.

Dale

iTrader: (12)

the early (pre87-88'ish) 2.8 flywheels were balanced to match the crank.

post 87-88'ish 2.8/3.1/3.4 are neutrually balanced. This the reason the one off my 93 s10 was ok to match with my 95 firebird engine.

KED85

I have THREE SPARE 2.8 AUTOMATIC FLEXLATES FROM 1985 vehicles if ya wanna play with them.
Just pay for shipping!
I will say that back in 1996 I paid $60 for a flexplate for a small block Chevy automatic.
You can always purchase a 3.4 flexplate, then duplicate it (using that 3.4 as a guide) on your existing 2.8 flexplate. Use the banged up 3.4 flexplate as your spare part item. Ask a tranny shop if they have any 3.4 flexplates laying around

WhiteBlaze

iTrader: (1)

ok.. I have a question then... I'm planning on swapping the 3.4 into my 84 bird... will the 95 3.4 flywheel work with the F body tranny?


Thanks,
Keith

KED85

Yep!
IF ya got a carb'd 2.8 here's what it looks like in end.....This is pic of my Blazer engine bay w/3.4

FbodTrek

Will the 2.8 harness and computer control it with no problems? I would think the motor would run lean....

Project: 85 2.8 bird

Mine ran fine w/the combo. Certain, outside & unforseen things messed my swap up. But before it happened, It was good

FbodTrek

Don't scare me now Project!LOL

Project: 85 2.8 bird

I had an engine fire fudge up my harness, wouldn't run reliably after that.

Just make sure your t-pipe flanges to exhaust manifold are sealed.

hint hint

KED85

Again,
ALL the original vehicle stuff, IF IT WAS IN GOOD/GREAT/REBUILT/REPLACED/UPGRADED shape, will work just fine.
When I drove my swap boogie project home, I was stopped by the Fuel Injection wire harness that was too close to the EGR to upper intake manifold pipe. After I removed that harness from the closeness of the bendable pipe, all was fine.
You will not have a problem IF ya keep the project simple.
Keep reading what we reply, no need to worry. We'll get ya thru this.
50+ swappers and one chicken?
NOT ON THIS BOARD!
Again insert the 3.4 supplied injectors in he original vehicle 2.8 MPFI system, all is well.
90% of the parts ya need to swap over to the 3.4 long block ya purchased are supplied on your original vehicle 2.8 engine. A few from the 3.4 ya bought, rest are new gaskets or upgraded new parts ya inserted/replaced.
When the combo'd 2.8 stuff onto the 3.4 is started, it is operated by the original vehicle computer. No need to change PROMs or any of that stuff. Ya upgraded power by cubic inches, not microchips. I've coached many thru the boogie (so they don't trip on their own two left feet!) & my personal Firebird swap has gone thru 2 of the toughest CA smog tests & I pass with flying colors.
You can do this! Keep sticking to attention to details, that's best receipe for the success!

TechSmurf

Are you sure about the injectors, Karl? It seems awfully silly to do this to a mass-airflow vehicle without reprogramming the chip for the higher flow rates.. the 2.8 mass-airflow system can compensate readily for the 3.4, but I see it running pig rich with 4pph extra fuel per injector without tuning... I mean, I'm pulling.. or pushing, rather.. more air than a 3.4.. and I'm not running into injector problems. The injector swap is for the speed density guys..

EDIT: After a little mathematical fiddling, I'm probably limited to about 5000 with static injectors.. and about 26 cfm over a 3.4 Kids, please.. don't try this at home =\

The 3.4 at 5000, however, is still within the 85% duty cycle.. barely. Upgrade is reccomended.. upgrade without informing the ECU is silly.

KED85

I disagree
Again TWO of CALIFORNIA TOUGHEST SMOG TESTING & on the read out I pass either minimum or almost zero pollutants or zero pollutants.
Not saying don't experiment with chips or prom or whatever.
This is a custom swap. And if ya do the 2.8->3.4 swap it is YOUR custom swap.
My version is dead reliable, no problems, passes smog, leaps over hills, keeps on running, doesn't foul plugs either (I run for a 3.4!! Bosch Platinum plugs & Accel stuff).
I've offered my receipe for this 2.8->3.4 Long Block Swap Boogie.
Again, this is a custom swap & adjust accordingly if ya so desire.
My set up runs flat out perfect & strong & proper.
I put the 3.4 injectors into my 2.8 fuel rails & used my original vehicle ECM & original vehicle factory Los Angeles Van Nuys Plant assembly line installed PROM.

LT1guy

iTrader: (1)

Its an '87...that may be the difference. The 3.4 we used is a '95.

Project: 85 2.8 bird

I remember when I worked @ AZ, looking up an oerl pan gasket for the 2.8, it asked how many bolts it had. I think the one w/more it called a GM goodwrench block or something like that.

KED85

I've heard there is a change over to a flat lower lip of timing chains covers.
Lucky later year owners!

FbodTrek

NOW, My flywheel just came in yesterday (it's almost a pound lighter than original). I was looking at the 3.4 lower intake manifold VS the 2.8 lower, is the only difference the absence of the cold start injector? Can I do the swap without the use of the 7th injector? as soon as I finish replacing an intercooler in an Isuzu NPR and replacing head gaskets in a Taurus, My Camaro is going on the lift. Shouldn't take long to pull the motor. I do need to know if I should use the lower intake though. Thanx as usual...I'll be 3.4 powered in a week tops!!!!!

KED85

Nope
You swap to the original vehicle intake.
It works better in the swap.
Yeah, close but nope.

FbodTrek

That's just one more gasket to buy . I was going to replace it anyway but, that makes sense. Oh yeah, the plug on the passenger side head-NO chance of it coming out (Tried every trick imaginable, heating, penetrant, impact driver, impact gun, massive breaker bar etc.) needless to say-looks like I'll be using the one on the front of the driver side head. Assuming of course that I don't already need it for somthing else. Theres a temp sensor of some sort in there now.....Any suggestions?

Dale

iTrader: (12)

that sensor in left front head is for the guage in your dash.

I suggest using the 2.8 intake, as it also has an extra coolent plug in it.

The plug in the head requires being heated up, then removed with proper tools.

KED85

That plug is JOB ONE.
It is a 5/16" recessed Block Plug used for a water passage.
It is removed by a TANK OF FLAME TO HEAT IT WHITE HOT, then it is removed easily. Cherry Red isn't hot enough! It must be cooked to White HOT, "quickly" & "removed" while it cools. Hand held propane set up is wasted effort! BIG (or portable scuba gear sized) tanks set up!
Last time I did mine my plumber has a welding tank set up & both of us it took over 1/2 hour using every tool we could. Screwdriver & vice grips & lots of after beers!
First time was way less time, but that plug removal is a real important step.
Make sure you follow that suggestion, removal of the plug.
It will come out.
NO need to remove head for this.
Find one with portable welding tanks & ask them to visit (like a plumber).
The plug is "rusted" in there from being heated & cooled in a water passage.
You will succede in this detail.
PS, Don't strip engine until after this plug is out. Having a fully dressed engine gives ya lots of places to "grab on & twist or hold!"

FbodTrek

I heated it up red hot and used a square plug socket on a 1/2" breaker bar..... No luck, I stripped the square hole... oh well. I have idiot lights in my car, so using the front one will do. I plan on installing Aftermarket "element" type temp guage anyhow.

FbodTrek

FINALLY had the time to put my Camaro on the lift, pulled the motor out . I'm really glad i decided to do it too. My fuel lines had split O-rings and my rear main was pouring its **** off. Managed to pull the motor without removing any accessories (minus the power steering pump, those banjo fittngs **** me off...). I got some pics with Sonar's Digi cam, i'll post them soon. Now, tommorow I shall swap all of the good stuff. YAY!

Dale

iTrader: (12)

futher then I am, keep wrenching :rockon:

AM91Camaro_RS

i always pull all of my accesories off and leave them hooked up in the car. that way i have less fluids to mess with and no freon to mess with. just thought i'd share...good luck with the swap!

FbodTrek

Yeah, usually when I pull a motor I leave the accessories, but I plan On Painting EVERYTHING.... No ugly brackets for me!. And my A?C doesn't work , oh well....1 or 2 days to go.

Maverick H1L

iTrader: (8)

I have to know one thing for the future. What is the bore size for the 3.4 and can a 2.8 stock block be bored out that far safely? It's going to have to be bored anyways, I do think, and I might as well drop in a 3.1 bottom end while it's out, so maybe I am thinking of having a backup short block in case something happens.... I know the 3.1 is a stroked 2.8, and I assume that the 3.4 is a bored/stroked 2.8, seeing as how they have the same block in terms of bolt patterns and all.

And can anyone recommend a manifold and engine paint for me?

Dale

iTrader: (12)

your correcet on the bore/stroke.

Commen bore for 6/60 is .010
I read max bore is .030

Somewhere I have the exact specks on stock crank n bore, but dunno where it is

Dale

iTrader: (12)

found my info, it was at work

2.8.. 3.500 bore x 3.000 stroke
3.1.. 3.500 bore x 3.310 stroke
3.4.. 3.620 bore x 3.310 stroke

KED85

One cannot "Safely" bore out a 2.8 block to 3.4 for and expect longevity on road miles.
Start with fresh complete standard bore engine.
The cost these days for the whole 3.4 thing is so fairly priced. Avg is about $500 these days.
One person ever got his 3.4 complete for $210!
Search for the better solution & you'll be happier for the human effort spent.
You'll be on road quicker, too! Short as one solid weekend!
Try that with machining, parts selection, effort to assemble, break in time, etc.
All that does add up & can be replaced by one wise 3.4 long block purchase at $500 avg. price. One stop shopping!

FbodTrek

Changed the intake ((thankz for warning me about the gasket issue!!!)) I put a new timing chain on, painted EVERYTHING. This motor is gonna a t least look fast, lol! Tommorow I'll put the accessory brackets on along with the lower plenum and injector rail setup (gonna make it shiny!). Nobody mentioned relocating the knock sensor on the passenger side, or having to re-adjust the rockers....shame on you, lol . Oh well, I'll get em as close as possible and work things out a little later. If I'm lucky I'll have the motor in the car by tommorow evening.

Maverick H1L

iTrader: (8)

I think I forgot to add that I want to BOTH install a 3.4 and rebuild the 2.8....

And what is this about an intake gasket issue? Is that why we need to have a 2.8 intake gasket set? As it seems I am doing research on the swap right now, what is supposed to be done with the 3.4 knock sensor? The 302 ECM don't use it, I believe (according to stupid Haynes, it does, but I don't know where the thing is).

KED85

On top of the engine is the cam sensor. You leave that alone & just wrap up wire or cut.
On the knock sensor, just remove it.
On both of my 3.4 swaps, that's all I did.
But I have a 1985 platform vehicle and your vehicle may need a knock sensor. There was no problem for me to leave that hole unplugged.
Yeah, ya follow the directions for the 3.4 ->2.8 intake swap and yep, ya need readjust valves.
Now ya know why so many lifter adjustment issues after a head gasket job or the 3.4 swap boogie.
On my Blazer, I still need to readjust the valves after the 3.4 swap.
Great to hear how much you're enjoying your project. Keep at it! PS You will NOT be slow anymore! Make sure all bolts & such real tight & all mounts in great shape! Teething pains go hand in right gas pedal foot!

Dale

iTrader: (12)

knock sensor needs to be moved from front top pass side to bottom rear pass side.

See, I told yea

FbodTrek

My 2.8 must have been from a "newer" 2.8 equipped Car. It had a knock sensor on it as well, but it wasn't connected to Anything. My harness doesn't have a connector for it... Oh well. The knock sensor in the old motor was in the water jacket though...??? Usually they are in a blind hole. Anyhow, I got busy with OPS today, ended up staying to 8:00. No biggie, I got just about everything ready to go back in, jsut got to hook up th cold start injector line and put the AC compressor on its bracket. Funny, I was pulling the plugs out of the 2.8.....THEY"RE TORCHED!!!!! The platinum tip was burnt off! I imagine I had a few burnt valves as well.... I'd be affraid to see the rings.... Anyhow, I'll be taking more pictures, I'll post them after I get the motor in.