I picked up a 98 Z28 with a decent build to it. 243 heads that have been worked over, cam, LS6 intake, long tubes, etc. It has a spun bearing and from what it sounds like there isn't a whole lot of hope for the 98 blocks, can't do anything if the cylinders need any work. Also, it has oil galley issues in the back of the block. My plan is to get a 6.0L and build a short block and then drop the top end from the 5.7 back on it. While I'm working on that, I'm thinking of just getting a used 5.3 long block, bolting everything on (reuse stock 5.3 injectors, 42lb injectors would be too much) and run it as is for now. I'd have to either get the PCM retuned for the 5.3 or get another stock 98 PCM for the time being. Any thoughts or other advice/ideas? I want to keep my temporary option cheap so the money goes into the new block.

 

Why not just get spend a few hundred extra and get a used 6.0 long block now?

 

The idea is to build the 6.0L (machine work as needed, balance, etc), so I would drop the 5.3 in for now to drive it while I work on the 6.0. Otherwise I have to get two 6.0s. Most people around by me want a king's ransom for them, unless I happen to come across one in the pick n pull before anyone else does, but it seems people have an inside scoop on those lol.

 

If you get a good one, it shouldn't need any machine work and should already be balanced. You're going to spend $1500 in machine work for what might be almost zero benefit depending on the circumstances.

 

Yeah, but I won't know if it needs that work until I take it to a machine shop. I'd be buying a used 6.0, likely from some kind of a junk yard. If they're in a yard, they're likely there due to high mileage, etc, unless I happen to find one that was involved in an accident. If I get lucky, I won't have to have much done. I wasn't aware LQ4 engines were already balanced, don't recall hearing anything about that before.

 

This isn't the 70s and 80s anymore. Engines come from the factory internally balanced and able to do several hundreds of thousands of miles.

 

I know they're internally balanced from the factory but how well are they balanced. There seem to be quite a few posts in here about guys getting their rotating assemblies checked and having some balancing work done. It may not be a lot, but it sounds like these still need some work done, based on other posts I'm finding in a search. If I have to have it bored, then new pistons would be in order and might as well drop a couple of hundred more to have it balanced. Do all the block work once and not have to drop the front end out of it again.

Found a couple of these quotes in other posts related to balancing, which I agree with:

"Going cheap=expensive in the end."

"Cheap, fast, reliable... pick two because you can't have all three at the same time. If plan on running more than 6k rpm from time to time, then get it balanced."

 

This post was more about what happens before/during building that, not so much building that engine. Though I do appreciate any thoughts on any of it really.

 

If it'll last 300k miles being able to turn over 6k+ RPM, then there aren't any 'issues' related to balancing.
I hit 7600 RPM on my way to work this morning with a 240k mile engine being stuffed full of boost. It didn't fling apart.

Cheap, fast, reliable are all VERY obtainable now. I'm starting to think that those are the words of mechanics who make money on your gullibility.
If you walk into a machine shop asking if it needs machine work, its going to need machine work.

 

JoeNova is very accurate with what he says about the stock factory engines. From GM the stock LS engines are balanced very close to what used to be racing specifications back in the day. I have 250,000 mile LS in in my 02 Z28 that I hammer just as hard as ever and reasonably expect to see 300,000 + miles. The old 02 Z28 may get heads and cam but it won't get rebalancing of these stock short block. Total waste of time and money.

Building a new engine (LS or otherwise) or short block from scratch with various parts from various vendors that's another story, I want that balanced for peace of mind.

In short, listen to JoeNova he's given sound advice on the question at hand.

 

Nevermind on that comment

 

So if I wanted to change out the pistons to get the compression back up, just balance those then? Ideally I'd like to be putting down more power than it currently has (or had before the spun bearing). It dynoed at about 410 with the 5.7. The only thing I'm aware of that was done to the lower end was Katech rod bolts. All the other work was from the cam up.

 

You should be able to rebuild the ls1 no prob...

http://www.ws6project.com/user_stor/...oducts_id=8564

 

After thinking about what was said in here, I'll forego the 5.3 and go right to the 6.0.
I found a yard not too far from me that has a large inventory of 6.0s. They said $1000 for a running short block or $250 for a short block that rolls over, but that's all he can guarantee. What are your thoughts on one of the short blocks for $250? For that price, I'd think pick it up and pull all the caps to check surfaces. If nothing is glaringly bad, regasket it and a new oil pump then put all of my stuff from the 5.7 on it.

 

If you were planning on spending $1500 in machine work initially....you can buy 6- $250 short blocks that all go bad before you're at machine work money...start by tearing into your's and seeing what's reusable and go from there. If the top end is in good shape, $250 for more cubes and reuse what you have sounds like a good deal.

 

When you say "tear into yours", are you referring to the current 5.7? The top end should be fine, it's only got about 12k miles on it since it was installed. My concern with the 5.7 is that the block isn't really machinable and from what I read, the rear oil galley is an issue.
The engines I've rebuilt in the past have all been the older 1st gen SBCs, so I guess I'm used to the mentality of, if you tear it down, the block gets sent out.
As far as the machine work, I don't see it costing $1500, based on other work I've had done in the past, my bill has never been that high. Regardless I do see your point. Though, if I did go that far into any engine, it wouldn't be something I'm going to turn around and drop in over a month or two. So if I can get a good short block for $250, and as everyone says, it'll be fine in higher mileage, I'd rather go that route since the 97-98 blocks seem to have that oil galley issue.
I've always been leary of engines with an unknown history though, which is why my initial comments about having it gone through. It does seem that these are much more tolerant than anything else I've dealt with.

Not trying to argue with any of you guys on any of this, just that it's not what I'm accustom to so I hope you can see where I'm coming from.

 

If you're referring to me, you have 2 options to me. First, rip the heads and pan off and take a look. It'll tell you if the block is good. You can't bore the 98's, but a spun bearing doesn't mean it needs to be bored. Plenty of people tear down a motor and re-ring and bearing it and run it. If you pull the heads and the cylinders look bad, then pick up the $250 6.0 short block and reuse your LS1 top end.

 

I know the spun bearing doesn't mean it has to be bored, but that block does still have an oil restriction in the back of the block, which is one of the concerns for me. So even if all it turns out to be is a spun rod bearing, that issue will still be present in that block. Adding to that issue, if metal shavings have gone through and put any marks in the cylinders, then that block is junk, since you can't bore them. The plan is to get the engine out as soon as I have the garage space to do it, but I'm the type who likes to have options and as much info prior as can be. I like to know exactly what I'm getting into and looking at ahead of time if I can.

 

I've had multiple 98's and never an oiling issue. I agree with always wanting to be prepared ahead of time, but there is such a thing as overkill

 

Fair enough, I'll get it apart and see where I'm at, go from there.

Thanks