Hello, I've got a 1984 Sport Coupe with the Carb 2.8 L and I've got a failed connecting rod bearing. I've been looking for a rebuilt or remanufactured 3.1 litre engine, but I can't find one for under $1500!!! Even rebuilt!!!! One of the people who replied to my other post about the connecting rod bearing said I could find one for like $500-600. I need help please, is it more cost effective taking the parts I need machined in my 2.8 to the machine shop or just replacing the engine. That guy also said the machining would be 300-400 dollars. I'm also working on a possible deal to get me the 350 v8 for 500-600 dollars, but I need to make sure its in good condition. Also, with a bigger engine, will I have to get a different Transmission, because my current gear ratios are great for the kind of driving I do, but I don't know if i need a tougher transmission or not. (automatic that came with the 84 2.8 L Sport Coupe) So, please give me some feedback.

 

Autozone around me carries slavage engines with a 1 year warranty for around $850.00.

 

Just go with a 3.4L, it's the same block, bigger displacement.

 

I recently spun a rob bearing in my 3.1. Look because I found crank/rods/pistons out of a used motor for $45. I haven't checked my main bearins, but if your block isn't damaged - just reploace the rotaing assy (probably get away with new crank and one rod.

Reman cranks run about $250 at Discount and ARI has rods for $17, but most wrecking yards can pull a crank for you for less money.

 

Keep the six and do it right. If you are thinking of switching to a V8, the costs alone will make you think again. You need a radiator, all the brackets, a V8 700R4 (or the THM2004R, don't remember when they switched over), engine mounts, front springs, and a whole lot of time on your hands to do a swap.
You can get an engine master kit from most major aftermarket parts houses for less than $400, which includes a full rotating assembly and all the gaskets you will need.
If you do want to swap, like was suggested, either get a newer 2.8 (better heads and bigger crank journals), a 3.1 (2.8 stroked) or 3.4 (2.8 stroked and bored out). The newer 2.8's became available in 85-86, IIRC to 89, the 3.1 in 90 to 92, and the 3.4 from 93-95 and a half. Go to a decent yard that has a decent rep, and make sure the engine has some sort of warranty on it. If the yard won't warranty the engine, then don't buy it. Make sure that they run the engine in front of you if at all possible, so you don't get any surprises later.

 

:edit, since there is no edit in the Quick Reply:
DO NOT RUN THE ENGINE AT ALL IF YOUR BLOCK IS STILL GOOD! I had a bad bearing on my #4 rod for a long time, thinking it was a bad lifter. Only when the bottom half of the rod blew through the side of the block did I know it was a bad rod. Have the car towed to a shop or do it yourself (not cost effective, since you WILL need an engine hoist just to get the oil pan off, and an engine hoist is an awful expense if you're only ever going to use it once. Cheap, they are around $200. The good ones go for a LOT more than that.

 

The oil pan can be removed by jacking the motor and removing the y-pipe. I did it without removing the dist, or even the cap/rotor. Removed the motor mount bolts and made a wooden jig to hold the crank pulley. Working by myself it took about 2 hours to get a rod bearing in my hand and this included unbolting my turbo and re-welding the bung in the pan (the reason the bearing got starved and spun). The weird thing is both halves of the bearing spun together and landed back in the correct location (or 180* out).

 

well, guys, thanks for the input, I've already gotten the whole engine out from under the hood, it's just sitting on an old tire. I've seen some engine master kits, and they seem promising, The block is still good. I did drive it to a shop that let's me use the tools for free (i.e. school autoshop), so I could have caused some more damage, but it still runs. So is it just more cost effective for the master kit than to get the old parts machined, cause that's what it sounds like. I would rather do the kit than go to my greedy machine shops around here. I'm going to hone and re-ring assuming the kit comes with new rings and there shouldn't be enough damage to justify a bore because the engine never locked up, I just one day noticed a loss in power and a bad tapping sound inside the engine, sometimes accompanied by a squeaking sound like that of shopping cart wheel that needs to be lubed.

 

I just noticed you have an 84. Make sure when you order the parts that you tell them the year, you have small main journals and need an early 2.8 crank.

 

You may have probs finding the right parts. For some reason, even GM doesn't seem to have the right rods in stock. 12515767 is listed as fitting ALL engines from 82-94 or whenever . However, the parts warehouses I mentioned may have them. The only thing I can find at the moment is from a company in CA called Powerplant. The ad I have doesn't list that they have rods for the early 2.8 (173 as they call it, the 2.8's displacement in CI), but you can try giving them a call at 661-861-0167 and seeing if they have them in stock. Either way, you HAVE to mention that you have the small journal 2.8 or your new rod won't fit right, and your crank won't go in the block.

 

ARI should have them, look in the sticky at the top of this forum.