Bought core block

[lspann3525]

Today I jumped the gun and bought a shortblock 5.3 included that seems to be from the 99-06 generation that I was going to rebuild just for a backup to go in a 2008 tahoe. The guy I purchased it from said it ran but burned oil due to high mileage.Im able to turn the engine by hand so thats a plus. I am in the process of removing the rocke arms and heads. I was doing some research and see the horsepower changed between the years and does anyone know if it was the programming or engine internals that changed that made the extra hp?

 

[donjetman]

https://www.onallcylinders.com/2019...de-to-ls-engine-specs-and-ls-engine-upgrades/

 

[Marky Dissod]

I was doing some research and see the horsepower changed between the years.
Does anyone know if it was the programming or engine internals that changed that made the extra hp?

Biggest change was switching from mechanical fan to electrical fans.
Besides that, rectangle heads do have better high-RpM flow compared to pope hat heads
(not sure about low-RpM flow, think VVT makes up for this).

 

[lspann3525]

Could this block be possibly 2006 because of the last digit

I was trying to decode this so I can tell which year but not finding much info??

The number below tells me its a 4.8l / 5.3l block 99-06

 

[Dustin Jackson]

@lspann3525 Many factors can contribute to the power rating like heads, pistons, and cam. There is a bit of work to get a GMT800 motor into a GMT900 chassis but it should be doable. Was it a good deal or why did you buy it?

 

[strutaeng]

Umm. I think you should have bought a Gen IV core to keep everything more simple.

The major difference between the Gen III and IV on the block are:

1.) 24X vs 58X crankshaft reluctor wheel. The wheels themselves can be swapped from one to the other, however. But needs to taken to a machine shop unless you want buy the Goodson tool. Obviously, crankshaft is coming out for this.

2.) Camshaft position sensor and count. Gen III has the cam sensor on the rear/top of the engine and it's a 1X reluctor. Gen IV has the cam sensor on the cam sprocket and is a 4X reluctor. An LS2 cover will get you the provisions for front cam sensor and there's a conversion harness that goes from a Gen IV to Gen III... I'm not sure if there's anything the other way around, but I'm sure you can do it.

3.) Knock sensors are on the top inside the valley cover on Gen III vs down on each bank on Gen IV. Going from Gen IV to Gen III, there's a harness to convert the different location and the smaller threaded holes can be reamed and retapped for the larger thread of the Gen III knock sensors... I'm not sure what going the other route would entail.

4.) I'm sure there's other smaller stuff to consider...

So to summarize, I'm sure it is possible, but you can see there's plenty involved. I'm assuming no DoD/AFM stuff would get reused, of course.

 

[lspann3525]

I felt it was a good deal I got everything except for the wiring harness and computer. Came with a engine stand. Over the last couple of nights Ive removed the heads, camshaft, pistons and crank. None of the bearings seem to spun everything looked good for a high mileage engine. Im going to drop the block off at the machine shop and have them check the bearings (cam, freeze plugs and main bearings). I thought about reusing the crank but being high mileage I may need to replace it along with cam,oil pump and timing chain.

I did notice the reluctor will on this crankshaft unlike the crankshaft in the 08 5.3l. Are there any upgraded cranks or improvements or is the factory cranks stable?

 

[Geotrash]

I felt it was a good deal I got everything except for the wiring harness and computer. Came with a engine stand. Over the last couple of nights Ive removed the heads, camshaft, pistons and crank. None of the bearings seem to spun everything looked good for a high mileage engine. Im going to drop the block off at the machine shop and have them check the bearings (cam, freeze plugs and main bearings). I thought about reusing the crank but being high mileage I may need to replace it along with cam,oil pump and timing chain.

I did notice the reluctor will on this crankshaft unlike the crankshaft in the 08 5.3l. Are there any upgraded cranks or improvements or is the factory cranks stable?

You can probably buy a new crank with the right reluctor wheel from Summit. I believe there is also a company that makes a converter box for the signals to convert them to the newer standard. Might be worth a Google search to see it you can find such a beast if needed.

 

[strutaeng]

Wait until the machine shop takes it apart. I recently tore down my LQ4 with 262k miles for a refresh and the crank journals looked excellent. Should have taken a photo. I didn't even bother "mic"-ing it.

The LS cranks are very robust and made from nodular iron (also called ductile iron). Folks push 800-1,000 HP through them on highly modified engines with stock bottom ends. If the journals look good, there's absolutely no reason to replace it in my opinion. Get the reluctor wheel swapped by the machine shop. I think my local shop charges $100 for this plus the part.

IIRC, the Summit Racing LS cranks are turned down. Maybe 10 thou or something like that?

@Geotrash I think the Lingenfelter converter box converts 58X to 24X, but not the other way around. But OP should look into that to confirm...

 

[petethepug]

Look at Summit. They have a Pro Series kit to turn the 5.3L into a 6.6L/400cc stroker monster. Kits come with matching cam and rotating assembly. Not sure on pricing but good to know when starting from a freshly machined block.

 

[lspann3525]

You can probably buy a new crank with the right reluctor wheel from Summit. I believe there is also a company that makes a converter box for the signals to convert them to the newer standard. Might be worth a Google search to see it you can find such a beast if needed.

Seeing that I need a convertor ill be using this engine in another car and look for a 07+ 6.0.. When purchasing this 5.3 block I totally forgot about the relocations of the sensors. But it my tahoe engine fails I will sure keep this in mind.

 

[lspann3525]

Wait until the machine shop takes it apart. I recently tore down my LQ4 with 262k miles for a refresh and the crank journals looked excellent. Should have taken a photo. I didn't even bother "mic"-ing it.

The LS cranks are very robust and made from nodular iron (also called ductile iron). Folks push 800-1,000 HP through them on highly modified engines with stock bottom ends. If the journals look good, there's absolutely no reason to replace it in my opinion. Get the reluctor wheel swapped by the machine shop. I think my local shop charges $100 for this plus the part.

IIRC, the Summit Racing LS cranks are turned down. Maybe 10 thou or something like that?

@Geotrash I think the Lingenfelter converter box converts 58X to 24X, but not the other way around. But OP should look into that to confirm...

Most of the journals looked pretty good but there was one in question where I could feel just a slight roughness running my finger across it. And the area on the rear of the crankshaft where the rear main seal goes around is questionable.

I forgot about Summit guys I havnt used that site since a teen but whoa those crankshaft prices are high.

 

[strutaeng]

Most of the journals looked pretty good but there was one in question where I could feel just a slight roughness running my finger across it. And the area on the rear of the crankshaft where the rear main seal goes around is questionable.

I forgot about Summit guys I havnt used that site since a teen but whoa those crankshaft prices are high.

Rely on the machine shop for guidance on this then. Maybe they can polish that journal or tell you a nearby place that can. They'll be able to tell you if polishing or turning will be required.

My machine shop referred me to a small (I mean SMALL, one-man shop near my house) that polishes cranks for a 5.3 stock crank I bought for a 6.0 build. The guy charged me $50 and was ready the next day.

BTW, do you have a budget for this build? It's a stock or stock-ish build, correct? Engine building/rebuilding is expensive in general. Throwing aftermarket parts into the mix blows budgets out of the water.

 

[lspann3525]

I dropped the block and crank off at the machine shop. While I was there one of the guys checked it with a mic. Said the crankshaft is good and will take standard bearings but just needs to be polished. No freeze plugs the screw ins should be fine. So the shop is doing cam bearings and checking piston bores.

At the moment I have no budget I may just go back stock depending on how expensive it gets. And im pretty sure I will need a tune if i change cam and pistons.

Im still in the process of locating engine wiring harness and ecm or going with one of the aftermarket control boxes

 

[Dustin Jackson]

@lspann3525 Keep in mind that there are different stock cams so make sure you are at least using the best factory cam I think it’s the l33

 

[Marky Dissod]

@lspann3525
Keep in mind that there are different stock cams, so make sure you are at least using the best factory cam.
I think it’s the L33.

Even ACDelco zombies can at least upgrade to a better version of what ACDelco has to offer for something very similar to what they already have.

 

[lspann3525]

Well the block checked out good still uses std bearings. Last night I got the main bearings installed and used a little assembly lube on them.

Can the main cap bolts be re-used? Also the side main cap bolts?

 

[strutaeng]

View attachment 428993View attachment 428994

Well the block checked out good still uses std bearings. Last night I got the main bearings installed and used a little assembly lube on them.

Can the main cap bolts be re-used? Also the side main cap bolts?

Very nice!

Main cap bolts can be reused. They are torque -to-angle (not to be confused with torque-to-yield, TTY.) Just clean them up, as well as the threads on the block. And apply a bit of oil to them when reinstalling them.

Side bolts should be replaced (I believe that's what GM advices, but it's because of the pre-approved (edit: pre-installed!) sealant on them. If reusing, apply a bit of RTV silicone sealant under the head. That's what I did on my build recently.

I'm assuming the machine shop installed new cam bearings?

 

[lspann3525]

Very nice!

Main cap bolts can be reused. They are torque -to-angle (not to be confused with torque-to-yield, TTY.) Just clean them up, as well as the threads on the block. And apply a bit of oil to them when reinstalling them.

Side bolts should be replaced (I believe that's what GM advices, but it's because of the pre-approved sealant on them. If reusing, apply a bit of RTV silicone sealant under the head. That's what I did on my build recently.

I'm assuming the machine shop installed new cam bearings?

Yep new cam bearings and hone cylinders. Polished crank

 

[strutaeng]

Yep new cam bearings and hone cylinders. Polished crank

Oh, I'm sure you know this, but when you torque the main cap bolts to the first torque pass, you are supposed to smack the crankshaft back and then forward a few times each with a dead blow hammer (to seat the thrust bearings). Then proceeded with the final torque-to-angle specs.

Then you should check the crankshaft endplay for specs. A cheap HF magnetic base and dial indicator is best, but I've seen guys use feeler gauges to measure the gap between the thrust bearings and machined surface on the crank.