Cratemaster

I just bought a 1984 Camaro Sport Coupe with the carburated 2.8 Liter V6 engine about 3 weeks ago. I've been really impressed with it, ran smoothly, passed smog after I put a belt on the smog pump again, and reconnected a few air hoses (i'm from california). A few days ago, I decided to put the throttle wide open and get an idea of the max. speed of the car. I was probably going about 105 or so, and then I got a pretty good loss of power, I couldn't keep it above 100 anymore, so I backed off the throttle and continued home. I noticed on the dirt road to my house i had trouble even getting it to 40 MPH. It worried me a little, but I was tired and I decided to check it the next day. The next afternoon, I started it to go to work, and even while it was idling, it developed a nasty knocking sound that increased in frequency with an increase in RPM. I drove it to work because I thought it was just the old smog pump or maybe a broken belt or something minor, but on the way I could barely get it to 65 MPH, so when I got there I listened under the hood, I checked the smog pump because it is very old and the man at Kragen said it probably will need to be replaced, but I found that the sound came from inside the block somewhere. I sadly realized it was a connecting rod or something. I asked a mechanic and he said it was probably a connecting rod bearing since I was able to drive it still. So i'm going to nurse it to school tomorrow morning and take it to the auto shop there and work on it everyday after school. Of course after I get it there I'll be taking the bus in the mean time. I'm very sad, I love this car so much and to make matters worse, I just installed a new stereo system myself in it this weekend. So the point of this post is to ask anyone for advice, hints, tips, information about bearing prices, and anything else that could help me out.

Pat Hall

iTrader: (31)

My very first bit of advice would be that you have it towed to your shop. If you have a rod knocking, the longer it runs, the more damage it does. In fact, if the bearing spins in the rod, it'll probably lock up the motor instantly. Ask me how I know. Even if it doesn't lock up on you, it'll be much easier to fix if you don't start it up and run it at all anymore. To do the job right, you'll want to take the crankshaft and all six connecting rods to a good machine shop, have the crank turned, and have all six rods reconditioned. If there's only minimal damage to the rod journal on the crank, they'll only have to machine off .010 on the journals to make them perfect again. They usually do the rod journals and the main journals both. Then you just buy new bearings that are .010 thicker than standard size. I'd suggest getting new piston rings while you're at it. Now's the perfect time to re-ring it too. You'll need a cylinder hone to give the cylinders a good surface for the new rings to seat. The other things I'd recommend doing would be to put in a new timing chain set, new oil pump, and take the heads to the machine shop to have the valve seals and guides checked, and replaced if necessary. Maybe even get a valve job done too. If you have to tear down the motor far enough to rebuild the bottom end, it'd be stupid to not go ahead and do the other stuff mentioned. Rod/main bearings only cost about $40, and a set of rings are about $30. A good timing chain set is about $40, and a complete engine gasket set is probably about $30-$40. Once you add in the machine work, you're probably looking at about $300-$400 total cost if you do all the labor yourself. The money you spend will be well worth it to have a nice, fresh motor again that should last you a long time. If you decide you don't want to do all this work, you can use your engine as a core and get a re-manufactured one for probably about $500-$600. You never know how cheap the parts are in a replacement engine though, and what all has actually been replaced either, so I'd highly recommend you rebuild yours. You'll know exactly what's been replaced, and it's also a rewarding/good learning experience to do it yourself.

ljnowell

I would ask what is the intended purpose. I dont believe much in re-ringing and engine, unless it has less than 30-40K on it. Otherwise I am a firm believer in a bore. If there is ANY ring ridge at the top of the cylinder a bore is necessary. I have found that for longevity, its much better off to just do it right. If the rings are OK (no blowby) then i would probably tear it down, keeping the rings where they should be (according to piston) and either have the rods resized and the crank ground, or just replace them. I saw on here where a member bought new 2.8 rods with bolts for 18.99 apiece. Not a bad deal. Anywho, dont mess with the cylinder walls unless you plan on boring the beast.

Pat Hall

iTrader: (31)

I actually agree on boring vs. re-ringing when it comes to a sbc. On a six cylinder, I'd rather use it as a boat anchor than spend the money to bore it and buy oversized pistons. Of course he should bore it if there's an obvious ridge at the top of the cylinder. My post was already long enough without going into that as well. Provided there isn't a major ridge, it's still a good idea to hone it and put new rings in while you're there. Might as well put a set of moly rings in there with a fresh hone job to improve the compression and decrease blow-by ya know? If it was my car, I would definitely use the 2.8 as a boat anchor and replace it with a V8, but if he wants to keep the 2.8, might as well freshen it up, and honing/re-ringing is definitely cheaper than boring on a limited budget. Judging that he's going to be working on it in an auto shop (i.e. high school), I wouldn't imagine he has a lot of cash to spend.

Cratemaster

Yup, I'd tend to agree with replacing with a V8, but I am on a limited budget and gas money is already really tight, so I'll stick with my V6, besides, I'd love to rebuild it myself and go through the experience, I'm going to go to school to get my A&P license and hopefully get certified as a commercial pilot, so the experience here will greatly help me. One day though, I plan on replacing the engine, when I get a career and money, and turn my car into more than just a vehicle for transportation.
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I do have the money to bore it, but if I don't have to, i'd like to not do it.

tom3

Crank kit, maybe a rod or two, cast rings, set of gaskets and you'll be ok for a while. The 2.8 is a good engine for gas mileage and staying out of trouble with the law. LOL.

Cratemaster

OK, well today I'm going to start the process of yanking the engine. I parked my car at the shop and informed the shop teacher of what I was doing. He chuckled at me too, every mechanic I talk to laughs at me when I tell them about my problem, I think they just feel bad for me, but the teacher should know I can do it. I aced his class last year.
Anyways, I know it is bad to drive it, but I didn't tow it to school. I drove it and kept RPMs real low. That's in the past now, I just need to worry about keeping grubby little hands of my car. Auto Shop is were alot of my school's "underachievers" go to slack off and fail without getting detention. So I've got to worry about idiots and stoners around my car. If I had more knowledge and a concrete surface at home, I wouldn't use the shop. Well wish me luck.

five7kid

iTrader: (14)

You've probably wiped out the crank. Meaning you'll need replacement parts.

Start looking for a 3.1 or 3.4 V6. Either are much better than any of the 2.8's put in RWD GM's.

ljnowell

The reason i suggested he not hone and install new rings really isnt for cost effectiveness, its because you are 100x more likely to end up with leaky rings, oil burning, and blowby when you re-ring. when you hone, you are removing material, effectively creating a larger bore. Install the same pistons and new rings, and things arent just right anymore, making a greater chance for problems. People do it all the time, and have no problems. And then a lot of people say, "why does my overhauled engine smoke?" Iwouldnt do it, but do as you want.

Cratemaster

well, I'm starting to get overwhelmed, this is my first time even pulling an engine, so I'm not sure what to do. I could afford a cylinder bore job, sounds like it might be necessary, but I can also probably afford a bigger engine, I'm starting to be tempted to upgrade to a V8, but I'm afraid of the technicalities such as electronics and computer/chips that my old carburated V6 doesn't have. I also probably can't afford a heavier duty transmission. The nice thing about keeping the same engine is that everything pretty much goes back where you pulled it off, so familiarity is also an issue. Any opinions? I don't want to spend more than I paid for the car on the engine.

Cratemaster

also, what do you mean by the 3.1 or 3.4 V6 being better than the 2.8? Are you talking about power, quality, or ease of service? Because I don't need more power right now, I'm used to underpowered vehicles, I mean I've driven a 96 HP I4 pickup for the passed 2 years, I just need efficient use out of my Camaro right now.

Apeiron

Honing the rings removes a very small amount of material, but mostly it's just putting new scratches in the cylinder walls to wear in the rings. If you're lucky, then after re-honing you're still within the tolerance for piston skirt clearance.

The people who have problems are the ones who just hone and re-ring without actually measuring the bores to see if honing is all that's needed. If they're out-of-round, or out-of-cylinder, or worn too large, then they need to be bored.

Pat Hall

iTrader: (31)

Start looking for a 3.1 or 3.4 V6. Either are much better than any of the 2.8's put in RWD GM's.[/QUOTE]
I think what five7 means by that statement is the 3.1 and 3.4 are a much improved design over the old 2.8's. I remember talking to a machine shop quite a while back, and they said they probably see more blown up 2.8's than any other GM V6. Swapping to the 3.1/3.4's is pretty common. You might want to go to the V6 forum and check out some of the posts there. I'm sure you can find plenty of info on how to do it. I could be wrong, but I'm betting it's not too difficult or expensive to do it. On the honing deal, another area where people screw up is that they hone each cylinder way too long, or do it dry. When honing, you want to use a 50/50 mixture of kerosene and ATF to lubricate the cylinder walls, and only run the hone in each cylinder long enough to achieve a decent crosshatch pattern. Doing it that way minimizes the amount of material that's removed from the cylinders.

ljnowell

To properly hone a cylinder, so as to insure that the rings will seat properly you will need to enlarge the cylinder at least .0015 to .002. This is too much in a cylinder that will already have some wear. IF the rings seal now, dont replace them, its easy, dont fix what aint broke.

Cratemaster

well, guys, I'm really close to getting the engine out now (the shop is exceptionally crowded). I'm gonna take a look at the damage, If it's not too bad (can be fixed with minimal replacement parts and machining) then I'll keep the 2.8, but If this is going to be expensive, I'm going to replace with a 3.4 liter. I need to start looking now, so could someone please show me a good site that I could order a new/remanufactured 3.4 at?

oh yeah, my 2.8 has a lot of corosion on coolant ports on the engine, so I don't know if that's normal/bad, but what should I do about that? Also, many electrical plugs disintegrated on me when I pulled them of (crushed) and the rest are going to disintegrate the next time I try to plug them in again, so are there any replacements for those that won't get so brittle?

Apeiron

Yes, a lot of material needs to be honed off to prepare the cylinder walls after boring to clean up the scarring left behind by the boring cutter. Around .005" is honed with a coarse stone, and the last .0015" are taken off with finer stones. To just re-ring though, the cylinder walls don't have that kind of damage to start with, so only the finest stones need to be used to leave the desired surface finish to retain oil and seat the rings. The surface finish is specified in microinches (IIRC something like .000 020" for a moly ring), so almost no material needs to be removed. It's not a "honing-to-size" operation, it's just a surface deglazing.

Cratemaster

Well, I know this is a dead post, but I just want to conclude it, I'm by no means done with re-assembling my engine, but I spoke with my uncle who is a certifide Airframe & Powerplant mechanic for Cessna (he used to work at a shop on his local airfield, but he got "promoted") and he said that if the crosshatch pattern is still on the cylinder walls with no "extras" or deformities, than it won't even need to be honed, judging by the relatively low mileage. After confirming with a machinist and a few gear heads I decided to just buy a ridge reamer and do a re-ring with new pistons (already done) Heck, one guy who's been rebuilding chevy's for a while said that new unworn stock sized parts in the warn stock sized cylinders could sieze up when the engine warms up--personal experience. I specified my engine's mileage and he said it's should be okay. I also used a new oil pump, reman crank, new cam, reman heads, and master engine rebuild kit. So far, my big problems are freeze plug removal, and finding a new wiring harness (complete assembly with male and female plugs)

slow_90firebird

Good Luck, dude. I think that site on the right hand side called EFI connection might sell new wiring harnesses. I would call them.

Also, I know what it is like to be in school. I am at a 4 year college in NH now training to be a commercial pilot. It sucks not to be working, but I really love flying and almost have my private certificate now so its a big tradeoff.

If I was in your boat, I would have sold the car. No offense, but I would be fed up with all that work for a V6. As it is, I might end up selling my car unless when I figure out why it is acting up it is a cheap fix. I am desperate for money.