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4.8 genIII
Came out of a 2001 Chevy Tahoe with 260,000 mi on it. Deglazed the bores and cylinder #6 looked like the pictures below (except the nice one). It's not deep but it is a little rough. It seems more like discoloration. Already ball-honed it.. it's still there.
I don't need to get 10 years out of it. Just want a couple years of boosted fun before I pull it out and THEN bore it out. I got it for nothing so I'm not breaking thousands of dollars worth of parts, I would just try to avoid the labor of pulling it out and replacing if I could. The pistons looked great. The crank and rod bearings looked fine. I included a picture of an example what the other deglazed cylinders look like. I could get it bored out but then I'd have to get bigger pistons and then get it rebalanced and I'm trying to be budget conscious. ... Save my money for the eventual turbo. Looking to get around 10lbs boost.
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I think it's a spend the money now or spend the money later kind of thing. I'm sure it will last a while that way, but if you have the funds take it to a machine shop or find another LS engine at your local junkyard.
You can see the line in the cylinder where the oil rings had been which indicates that it had been sitting in that condition for awhile. Was there any rust in that cylinder before you started honing it?
The first LQ4 I did looked similar but I could BARLEY feel it with my finger so it was pretty smooth, I broke the rings loose, cleaned the pistons, and it ran perfectly fine.
Just throwing that out there depending on how deep the pitting is.
As little as LQ4s cost, and as plentiful as they are, I'd pitch it and get another. It'll cost more to "fix" that one than to just replace it.
Then when/if the "turbo" crap ever materializes, go get another one, and build that one up. It's BEYOND POINTLESS to build a supposedly "turbo" motor and try to run it N/A, or vice-versa. One or the other but not both. Makes NO SENSE WHATSOEVER to build a total POS on the premise that "someday" you "plan" to "throw a turbo at it".
See this post for the sort of thing that happens when n00bz do that. https://ls1tech.com/forums/generatio...2-so-slow.html Don't make the same mistake: take advantage of Algore's wonderful invention, the Interwebz, and learn from SOMEBODY ELSE'S mistakes instead of your own, FOR FREE no less.
If you have a place with an engine dyno near you assemble the 4.8 and check to see if it performs well. If you don't have access to an engine dyno and you don't care run it as is. If you do care store the block in a corner covered in oil/WD40 or something that will keep moisture out and find another LS block to run.
I wouldn't spend A DIME on a 4.8. ABOVE ALL, not spend the money time and effort to "assemble" an OBVIOUSLY KNOWN fornicated sodomized one, then pay somebody to dyno it and see if it's good. You can probably pick up 3 WHOLE 4.8s at the junkyard WITH A WARRANTY for what it would cost to do that.
Use common sense. Instead of getting all single-minded focused on "fixing this free/paid-for 4.8", look at it as, you're at point B with a pile of shiite that doesn't work, and you want to get to point A which is an engine that DOES work: SO, what's the quickest, eeeeezyest, lowest risk, least effort, least expense, way of getting from point B to point A??? It'll cost you $xxx to "fix" it and "test" it and THEN WHAT if it turns out you've been polishing a turd and it still don't shine; but it'll cost $yyy for [insert alternative here] that DOESN'T carry that risk with it. Chances are VERY GOOD that the path DOES NOT go through anything to do with that POS block in the photos.
The block can be bored and honed to a 5.7 liter, so I don't see a reason to consider the block junk. It still looks good from the photos posted in the thread.
The block can be bored and honed to a 5.7 liter, so I don't see a reason to consider the block junk. It still looks good from the photos posted in the thread.
That's not a bad idea, since he's considering boring it anyway.
However, then he'll need a new reciprocating assembly, and then bye bye savings.
Yup, at that point, it becomes cheeeeeeeper to just go to the junkyard and get a 6.0 WITH A WARRANTY.
Point B to Point A. Don't lose focus. Pile of garbage, to working engine. EFFF "I got it for free"; think more clearly about what it will take to get there, and other ways to get there, and which one(s) carry more/less expense, effort, risk, time, money, danger of failure, etc. etc. etc. NOT "I got it for free so I'm gonna spend whatever it takes to 'fix' it even if in the end I still only have a 4.8 when I could spend only half as much and have a 6.0 instead".
Love this site. Good feedback from everyone. Keep in mind I'm in Bay area California and every engine at yards here are at least $1,000 for something that's got 150,000+ miles on it... For a 4.8.
I was able to get crank and rods from 6.0 for $50. I'll buy cheap eBay pistons, gap the rings and add some more eBay cheapness in the form of a turbo and then run it till it blows up. Two tears and a bucket f&#k it.
Already have Clevite main and rod bearings from another project. Already have the cam bearings installed on this block. I'll save my 3.780 Hastings rings for another 5.8/4.8 rebuild.
The way I figure it, I'll have a rebuilt iron 5.7 engine for about $1100 that's eBay ready for boost.
Same engine around here from any shop would charge me $4500 for the same thing.
I think it's a spend the money now or spend the money later kind of thing. I'm sure it will last a while that way, but if you have the funds take it to a machine shop or find another LS engine at your local junkyard.
Cheapest long blocks around here are about $1,000.
Yup, at that point, it becomes cheeeeeeeper to just go to the junkyard and get a 6.0 WITH A WARRANTY.
Point B to Point A. Don't lose focus. Pile of garbage, to working engine. EFFF "I got it for free"; think more clearly about what it will take to get there, and other ways to get there, and which one(s) carry more/less expense, effort, risk, time, money, danger of failure, etc. etc. etc. NOT "I got it for free so I'm gonna spend whatever it takes to 'fix' it even if in the end I still only have a 4.8 when I could spend only half as much and have a 6.0 instead".
Problem around here is long blocks are like local rents... Absolutely ridiculous. $1,000 for a high mileage 4.8. called many yards and wreckers. A new engine is about $4,500.
Hey I'm from the bay too...925...anyways u said you have a crank and rods from a 6.0....are they gen3 or gen 4 rods.....you can always put them in that 4.8 and make it a 5.3........and I feel your pain on the cheap ls motors around here.....these guys don't understand that they simply don't exist. ..nothing is cheap around here....I've gotten 2 motors off of ebay relitively cheap though. ..a 5.3 for $375 and a l96 6.0. For $800 ....delivered to my door........key is when you go on ebay search used chevy 5.3 free shipping. ....or 6.0 if you have a bigger budget. ....although I did also find a 3rd shortblock on Craigslist a lq4 for $500 in antioch. ...I jumped on that quickly and swapped the rods for gen 4s and bored it .030 with ls2 flattops and 64cc ls3 heads.....been running that motor for a little over 2 years now with no balance or no problems. ........pulled my lil angry 4.8 in favor for it...still got the l96 built up and the pissed 4.8 in the garage on standby for future projects yet unknown. .....cant find any smog exempt vehicles around here for cheap! !!........anyways I would just send it!!! If it was free who cares run it till it dies then you can always bore it out and make an iron ls1 with those spare rods and crank you have......believe me a 4.8 with a nice lil cam can be alot of fun.....mine has a 220/220 cam and it's a screamer turns 7/8k rpms all day long
06-15-2020, 10:03 PM
Cylinder wear, to bore or not to bore?? 
