RandyTyler

My son and I have a 1986 Firebird 2.8L mpfi with bad lower end. We are going to change out motor to the another 2,8L We have read the sticky at top of forum. If we understand right these are the only motors that will work? This includes the the following engines:
2.8L from the Fiero, Camaro, Firebird and TBI/Carb'd S10's
3.1L from the Camaro and Firebird (1990 - 1992)
3.4L from the Camaro and Firebird (1993 - 1994)
We would like any advice than we can get to make a more informed choice, thanks in advance...great forum and love the V6 section.

86transam.man

iTrader: (3)

First of all let me state that I do have experience with this I stroked my 2.8L to a 3.1L in my 1986 Firebird when I completely rebuilt the engine after it spun a rod. You can use any of the 60 degree engines in your Firebird however it has to be from a rear wheel-drive car as the front wheel drive(or transversely mounted) engine such as a Fiero is a different engine. If you are going to attempt to swap cranks around I have heard that the 3.1 and 3.4 cranks will not fit in some of the 2.8 blocks due to (i think) a crankshaft positioning sensor lobe on the crank.(not sure on why). Be warned to check any 3.1 block very closely for cracks too as they are notorious for cracking in the water jacket especially around the top of the block( i found this out the hard way). Basically a 3.1 is a 2.8 stroked and the 3.4 is a 2.8 bored and stroked, so you can use 3.1 pistons in a 2.8 block(I've done it). Also it is fairly simple to swap over to a serpentine belt at the same time especially if the new engine comes with some of it the only thing is changing two connectors one for the alternator and one for the A/C pump.

Hope this helps and good luck? If you have any more questions I will do my best to help.

RandyTyler

So, if we understand you correctly, any 2.8l from 1980 to present will work as long as it is 60 degree and rear wheel drive? What we are planning on doing is getting a salvage yard motor. So when looking look for 2.8l 60 degree motor. Then have the original heads rebuilt and applied to salvaged motor and whatever else we need to use from original motor. Are we thinking right? My son got car for $100.00 and on his 17th birthday it spun a bearing. He loves car and I have to admit I am impressed with it too. Thanks for your quick response 86transam

Gumby

Remember they change from external balanced engines to internal in 86-87

Put an external balanced flywheel n front balancer on an internal balanced engine and it will through itself apart being severly out of balance. Must make sure your flywheel and front balancer are right for your engine.

That is the only catch finding an engine as there is no set date, though you know 85 in external and 88 is internal but in 86-87 years you can find both in a car factory, they used what they got till they are gone.

RandyTyler

Hmmm,So don't change flywheel from salvaged motor? Then can we use a newer motor? Bear with me , new at this!

86transam.man

iTrader: (3)

Yes thanks Gumby I forgot about that change. If you want a little more power without too much hassle there are articles on here about how to swap in a 3.1 or even a 3.4. They are very well written that's where I got my info, and its a fairly simple procedure. Just involves changing a few sensors if I remember right of the top of my head.

RandyTyler

So, go ahead and look for a 2.8, 60 degree motor, but make sure not to change flywheel on salvaged motor. Before we buy I am hoping that I can get your opinions, money is tight and do not want to make a mistake! Hey I want to thank you guys for the great information. Very impressed!

89-bird

How much work are you looking to do on the swap ? If you just want to get it done and driveing again I wouldfind a running 86-89 2.8 in a camaro or firebird you can hear run in the car and drop it in place of the old engine for the least amount of work . Or find a tbi s10 engine that you can hear run and swap intakes and change valve cover gaskets . The reason I say get a fuel injected engine is because I don't think the carbed engine will run or perform right because the cams are settup different . Somebody correct me if i'm wrong .

RandyTyler

Pretty much do a quick swap for know, my son just got insurance on it for his 17th birthday and he wants to drive it. I was thinking a S10 tbi motor, probably the best chance. Anything that was year 1993 and lower was crushed for metal recycling last summer, including firebird and camaro. A real shame.

89-bird

Do the quick swap now and build your other 2.8 to where you want . You can add nitros or do a turbo or do both if you like you just need to build it how you want and can pay for . I would like to do both to my car but money is tight so for now still stock . I have seen a stroker kit for 2.8s on ebay if I remember correctly so you could go that route also and do different cams , injectors , headers , and all kinds of work to it .

RandyTyler

Good idea! Thinking of going with Turbo later on. I will be looking for salvaged s10 2.8 tbi monday. Am I right...Get Tyler back on the road as quick as I can. Know what ya mean by money being tight! Is it easy to find parts in TN for firebird? Here in montana pretty tough.

Gumby

I would not go TBI, stick with the MPFI, you can just swap all the top end MPFI stuff onto TBI engine though. If you went to TBI you gotta change computer and harness and.............

And yes don't change flywheels or front crank balancers from engine to engine unless you know they are both internal or external balanced.

89-bird

I went to ebay and found a 93 tbi 2.8 out of a sonoma with everything on it except for smog pump and alternator for $400 plus shipping if you want to check it out look under 2.8 chevy engine and it is in store catagory it was listed under 93 2.8 v6 . I here inTn an engine like that would go for more money in that shape .

89-bird

Parts in TN are a little hard to find where I live but you can find them if you do a lot of calling around or have a yard get on there network and find the parts you need .

89-bird

You could also pull the engine you have and check the crank journals for bad ware . And just replace the rod and main bearings or go ahead and replace them and the crank . I would check into it if I were you it could be cheapper than getting another engine . OH and replace the oil pump any way you go be it engine or replace crank and also do the water pump and thermostat for insurance .

bl85c

iTrader: (2)

Also avoid pre '84 small journal blocks. If I'm not mistaken small journal blocks may have been used as late as '86 in some s-10's/blazers.

89-bird

I believe you are correct sir .

RandyTyler

Wow! What informative responce, here is how I understand it. Try and find a 1986 or older tbi or mpfi to avoid small journal blocks . If I find a tbi I should and would change top end mpfi stuff. Should the heads be changed also? Here is what it is doing, when tyer starts it, it will rattle a liitle then go quiet. But when he revs it up you can here it rattle. At first oil pressure is at 40 lbs but as it warms up it goes down to 20 lbs. Talk about a great website!

89-bird

Find a 86 or newer mpfi or 87 or newer tbi . You don't have to change topends other than intakes and don't have to change heads at all . Is it knocking loud or is it ticking ? If it is ticking you may only need an oil pump .If it is a loud knock you have a rod loose and will need to change engines or do a bottom end rebuild to replace the bearings . On a 2.8 oil pressure should be over 40 lbs at over 2000 rpm no matter how warm you get the engine as long as you don't over heat it .

RandyTyler

Its a loud hollow knock, like something banging. I was hoping maybe oil pump but sounds like something loose. I will be looking for 86 or newer mpfi or 87 or newer tbi monday. The original motor has just over 200.000 on it, I would say wore out.

Gumby

Not really, if taken care of they go forever.
Mine has almost 230,000 and still runs strong and hard.

RandyTyler

Really Gumby, In your opinion would u rebuild or hunt down different motor? Could it be the oil pump gone bad. What was wierd is when we changed out pvc valve this all started. PVC valve looked like the original...The prevois owner was not to kind to this car.

Gumby

It could be quiet simple or thrashed.

Does it have an oil gauge in it?

some did factory.

Id though be picky about what you find, make sure you can hear it run or get some kind of a decent warranty beyond word of mouth.

That is buy semi new, like hit ebay for a long or short block, then just swap your top end and parts onto it. YOu know then the core stuff, is in good shape.

RandyTyler

Thanks Everybody...will let u know what I find and do!

bl85c

iTrader: (2)

What you're describing is rod knock. You'll need a new shortblock or rebuild the bottom end. You could get a decent used longblock cheaper than rebuilding. I would look for a 3.4 block for a little more pep. Get the 3.4 injectors if you go that route.

RandyTyler

Ya, thats what I thought...I will be looking for different motor today. I want to thank u and everybody else for the great advice. Very informative...

RandyTyler

Hey guys, We found a 1988 Camaro 2.8L MPFI with 95k on it. According to vin numbers of both cars the engine is a 173 CI V6 LB8. Looks very close to the same thing! $400.00 for motor. But salvage yard guy says it wont interchange according to his interchange book. I believe he is wrong, how does the camaro motor sound to you guys??

86transam.man

iTrader: (3)

It sounds to me like you are right and this engine should swap in. Mine came from a 91 Camaro into an 86 Firebird. Hope this helps.

Gumby

course it will work. long as its not a FWD or out of a Fiero it will go right in.

TomP

Sometimes their interchange book also covers things like computers and wiring harnesses and sensors and accessories (like smog pumps and EGR valves) when they talk about the "engine" versus the "short block". As long as you're going to keep everything the same on your car and only change the motor itself, it'll be good. (Your '86 has an LB8 in it also.)

It doesn't matter for the engine you found, but it was mentioned above, so: I believe internal balance started in '87. When the FWD motors received DIS in '87, they used a center counterweight on the crank (with notches for the DIS). That center counterweight allowed them to balance the crank internally, which allowed them to "neutral balance" the flexplate/flywheel. Either way, as was mentioned above, don't swap flywheels/flexplates. And yes, 82-85 did have smaller main journals (it was something like #1, #2, and #4 were small, #3 was large?), but I think in mid-85 is when all four mains became the same size.

Anyway, with this '88 Camaro motor you found, you'd keep heads/cam/flywheel/balancer. Everything else comes off of your engine and goes onto this one. You'll re-use your intake/sensors/wiring harnesses/alternator/starter/etc. Luckily we have digital cameras now so pictures are much easier- take pics of everything (with zoom) before you remove anything! Take special pictures of how wires run along the engine, and what clips they use, etc. Label things as "old engine" "new engine" etc. Take your time during disassembly to label & document everything will make the installation go much smoother. This would be a great time to replace the timing chain & sprockets too; you may want to replace the water pump (get a lifetime warranty one) if you do. Oh and if you don't have one, get a torque wrench and an 82-92 Haynes manual.

Now you've got an '86, right? Make sure that you take care of the sensor at the rear passenger head; that's a coolant temp switch for the fan. The replacement motor *may* have a pipe plug there. I ran into that whenI helped a friend do a similar swap with his Camaro.

Oh and as to that option for rebuilding what you have; the main thing is cost. If a bearing's spun they'll have to do work on the block. At that point, you'll either get a rebuilt crank or let them machine the original crank- and now you need bearings. While they have it, why stop there.. overbore (for cleanup, NOT for power!) the holes and hone, new pistons to fit the overbore, magnaflux the connecting rods too, and with everything else new, might as well get a new cam/lifters/pushrods, etc etc- it adds up fast.

One more thing- if you *did* take the heads to have them rebuilt, do not mix up the pushrods or lifters! They should go back in the same holes they come out of, and face the same direction too. But honestly, I'd just drop the motor in as-is. See if you can hook up a battery and starter to do a compression test in the junkyard so you're sure the motor's in good shape. At the least, you should be able to turn the crank with a breaker bar with the spark plugs pulled; if dirty water shoots out of the plug holes, it might not be a good engine to buy.

RandyTyler

I have already made arrangements with salvage yard to do compression test and most likely get it started. To do compression test take all plugs out, wedge throttle open and turn motor over around 7 times....RIGHT? I now know what to look for from all the help on this site. Excellant info Many Thanks too all!!!

bl85c

iTrader: (2)

Why get the heads & cam off the '88? Ask what they want for just the shortblock (block, crank, pistons & rods) with the flywheel/balancer. I got my 3.4 shortblock for just $150. You'll need a compression pressure guage to do a compression test. Make sure you let it pump out any crud before you hook up the guage. Like TomP said if anything nasty comes out you don't want that motor.

RandyTyler

He will sale complete motor only. I still am looking around maybe find a better deal or better motor.As a matter of fact going to look at a 2.8 out of a Chevy S10 4 by 4 for 250.00

89-bird

Remember if you go with the s10 to keep it all intact and the only thing you will have to change is intake system and sensors and put your accessories back on .

RandyTyler

Ya, use heads starter, ect from salvage engine Right???????? By the way could not find 93 tbi 2.8 out of a sonoma on ebay. Thanks for hanging in there with me!

89-bird

If the engine you get is the mpfi engine you will be able to use everything and drop it in . Just make sure all the sensors are the same .

RandyTyler

So far only engine I can find around here(88 Camaro MPFI engine, 450.00) Have money but dont know if motor has 95k or 195k, most likely 195k. Do u think it is worth it?...I am trying Spokane today...

89-bird

Does the odometer show 95 or 195 on it . If it shows 195 doesn't meen it isn't a good engine it just meens it is high mileage . If ti runs and sounds good go with it unless you find one cheaper or lower mileage .

RandyTyler

Odometer missing, salvage man says it was either 95 or 195k he couldn't remember. That 1988 most likely would 195k not 95k. Oh did find 1985 s10 2.8 for 250.00

89-bird

If you get the s10 engine just swap intakes , sensors , and of course new valve cover gaskets and intake gaskets . Is the car manuel or automatic . The engine you get will have to be the same unless the engine is a large journal you could use your flywheel or flexplate and put everything together .

RandyTyler

Manual, come to think of it so is the 88 Camaro

89-bird

I would go with it and use its flywheel to be safe because 85 s10 engines could be small or large journal cranks because that was the crossover yearin the s10 . The firebirds 85 and up 2.8 is the large journal . I believe like TomP said mid 85 was when they went to large journal . All 82-84 engines had a journal diameter of 2.4932 in to 2.4946 in and all 85 and up had 2.647-2.648 in journals . The large journal engines are better because the small journal cranks had a tendency to break especially if you had them weld and turn the crank back down to2.49... in diameter . In short small journal cranks are weak so stay away from them if at all possible . Also is your 86 a manuel or auto .

RandyTyler

Our 86 is a auto

89-bird

I know the s10 is cheaper but if you can't be sure of the crank that is in it I would go with the 88 and not have to change anything other than the flywheel over to flexplate and be sure to remove the pilot bushing to be sure your tourqe convertor mounts to the flexplate right .

RandyTyler

Ya I am leaning towards the 88 camaro engine...

89-bird

Ya I would go with the 88 engine and for extra insurance go ahead and replace the oilpump and water pump and thermostat to avoid problems down the road and your engine should last a long time .

MikeSmith0890

I did the same thing last year. Got the car for $700 bucks, the first day I get to drive it, it throws a rod, im thinking as bad as it was that it had already been thrown but they somehow muffled it. I spent approximately $700 just to rebuild the motor getting all new parts from the parts store. The car runs beautifully now, but if I had know then what I do now, I would have been wiser and swapped in a 3.4. The 2.8 is not a bad engine, but for the money the 3.4 is a wise investment.

bl85c

iTrader: (2)

While you have it out throw an S-10 torq converter on there, it'll give you a higher stall than the stock converter.

Gumby

SO where are things at now, Im been away with a cold/flu, still kicking my butt.

89-bird

Hey Randy did you get your engine yet ?