conan

iTrader: (5)

Just thought I would share my 5.3L LM7 refresh from a 2000 GMC Yukon XL. This Engine has 224,xxx miles on the clock and has never been cracked. The intake manifold is the only thing than has ever been removed for knock sensors.
The reason for the refresh was due to a failing oil pump (15-20 psi) @5,000rpm's. The lifters were getting loud as well. This engine was amazing on tare down, the Rod and main bearings had absolutely no wear on them the machine shop thought I was BSing them about the mileage. We ended up replacing the cam bearings and piston rings. The bores in the block still had crosshatches in them. The machine shop honed the cylinders .001 and still had .001 tolerance left. Rods, bearings, and mains were checked and we decided to reuse the original main and rod bearing. I have never seen an engine with this many miles look so good on the internals, the 5.3l has been a tough little motor, so let the TLC begin.

Big thanks to Aaron at Texas Speed, We ended up with new ls7 lifters, Melling oil pump, ls2 timing chain, PRC 5.3L heads with ls6 springs, MSD wires, TR55 plugs, and every gasket / seals for the entire engine.

Here's some pic's

Day 1.


Reassembly.

RezinTexas

looks nice.

my 145k LM7 also looked perfect on the inside when I tore it down. Impressive motors for sure!

dr_whigham

iTrader: (49)

Looks great! What paint did you use?

Edit: I know a WIX 51522 when I see one!

91sonomast

I came back to this thread to ask that ^ lol

conan

iTrader: (5)

Thanks man, I was definitely not expecting to see things in that good of shape. If the oil pump wasn't on its last leg I would have never pulled it out, great motor for sure.

51522, good eye lol.

The orange is krylon 300 deg hi-temp rattle can. The silver is a stainless steel paint I get from the hardware vender...
https://www.kimballmidwest.com/catal...?p=202.67.2902

spent21

iTrader: (6)

how many miles have you put on the truck? I know you said 224 K total. I was wondering what Oil you use and how long you've had it.

scarybowtie

iTrader: (9)

Looks really good! I painted one motor Orange, my old 406 build. Lasted 2k street miles amd spun a rod bearing at the track. Rebuilt and painted it black and its still alive a couple years later. Lol. I may try Orange again on my next ls1 build after seeing yours.

JRENIGAR

iTrader: (37)

I would like to know this as well. My wife has an 04 Yukon with 120k on it thats still purrin like a kitten...

bww3588

iTrader: (49)

Looks great, even in the disaster that is a 99 up gm truck engine bay. Lol

91sonomast

Does look good, has helped me make my decision on painting my engine.

remauto1187

iTrader: (1)

"Rods, bearings, and mains were checked and we decided to reuse the original main and rod bearing. I have never seen an engine with this many miles look so good on the internals, the 5.3l has been a tough little motor, so let the TLC begin."

God i hope you mean that you and the builder decided to use STD size bearings (NEW) and NOT that you used the original bearings that were in the engine when you cracked it open.

It seems its pretty common for these LS generation engines to show very little wear after many many miles.

Ive got a LM7 5.3L on the engine stand right now and it has 120K on it and the crosshatches look like they were put in last week.

Great paintjob BTW! Looks pretty sharp.

conan

iTrader: (5)

Truck was brand new when I got it 30 miles. I have done all the maintenance its whole life. Oil/filter/air filter changed at 3-4 thousand miles. I use Exxon elite 15w40 it's a semi-synthetic - heavy duty diesel oil that I use in all my liquid cooled engines at work.

Thanks dude Love Chevy orange.

Thats the truth, its amazing there was a real engine under all the crap on the top side.

Hay dude can I borrow your stapler. LOL



Thanks man, and no I mean this engine got the same bearings that GM blessed it with 12 years ago. I like to live dangerously Bearings we put back in on the same sides they came from new main/rod bolts. We'll see what happens. Every thing was as close to GM's tolerances as it gets. The bearings even had that crisp fitment when I was assembling the engine.

remauto1187

iTrader: (1)

Oh i have no doubt that your clearances were still good, these are some pretty amazing engines but look at how many times those bearings have been hot/cold cycling....eventually the bimetals will start to seperate just because that what physics will cause.

I woulda put new ones in ....a "new" engine. Not really all that expensive and i wouldn't chance a rebuilt engine on used bearings. Thats like running your neighbors used motor oil in your brand new engine!

wildcamaro

iTrader: (15)

Wow man I like to see that! I have an l33 with 200k on it that I am going to rebuild. I pulled the oil pan and it looked beautiful gold tint and very clean...I'm hopin I can get away with a home and some rings and bearings...that is ballsy to run the original bearings but I'm glad to see someone try because you really can't speculate about you have to try it in the real world and see, you are a pioneer of sorts lol..I would try the same thing if I see you have good results (still would check oil clearances though!)...anyway good luck man I'll be watching this thread to see if your successful!

ZQ8LS1

iTrader: (3)

Engine look's nice.

Slick68

iTrader: (7)

That looks good. That stainless steel paint looks kinda close to some VHT header paint I plan to use on my engine pieces.

chrisfrost

iTrader: (8)

I've got a 99-01 5.3 with unknown miles ,,,,,,,probably somewhere between 80000- 120000 and the bearings had no wear so I had originally planned on reusing them but 2 or 3 had some grit spots embedded even though they scraped away and sanded smooth (2000 grit) I decided it best to use new ,,,,then after I bought ARP rod cap bolts I had to get .002" larger outer diameter bearings ,,,,,,,when I disassembled ,,,,,,the pistons had almost no wear except right where You measure the little lines were about half worn away . Not much wear at all but I decided to put new Speed-Pro 4.8L flat tops which were only $180.00 for the set at Summit . Looks good

conan

iTrader: (5)

Thanks man, I realy had a hard time throwing those bearing away. This is the 7th rebuild/refresh engine I have done with my machine shop, if he tells me something needs to be done I do it. He felt the same as me after he miced every thing, the man hasn't failed me yet. One of the big factors in this desition was its a stock engine shifting @5,500 rpms (rarely) not my blown ls1 shifting at 7,000 rpms every time the car is on the road. Good luck with your rebuild this was a fun project.

Thank you

Thanks man.
I looked in to that VHT paint, they have some cool colors in the high-temp. Hope it turns out well.

Thanks man, The more I read about these 5.3L the more I like them. Alot of high milage people chiming in with good stories of durability.

TEister

any machine work done to the block?