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Changing the heart of my '03 Avalanche "Knight Rider" truck.

redheadedrod

SM 2017
PM 2015
Full Member
Joined
May 15, 2011
Messages
3,187
Location
Muskegon, MI
So I am starting a thread to detail the upgrade of my truck from its 280k mile 5.3 with recently replaced castec heads on it to a bigger more powerful engine.

I will be picking up an engine (Probably before I repair the rear end in my truck).
I have a couple engines I will be looking at this next week. They both are out of silverado 2500's so I expect them to be LQ4's.

I WELCOME any suggestions and corrections to what I am looking at. Other than the machining I will be doing this build myself. I am still researching parts to do this.  Yes I could buy one already prefabbed but I expect I will be breaking parts down the road so I want to know how to fix stuff myself.
Plus with what I do at work currently my skillset has improved to the point that rebuilding a motor or transmission doesn't scare me anymore.

So I expect to do this engine in three stages...
1. Disassemble, machine as necessary and assemble the bottom end for this new engine. Will use forged bottom end and looking at going with a stroker kit. Not sure if I should go with a 408 kit or smaller. Will be looking for one that doesn't need any machining of the block for clearance. Will assemble and install into truck.

2. Top end work... Will look at better heads and cam for my truck knowing that I will be adding a Magnuson SC in the near future and building with a mind to using E85. I understand E85 just requires an injector upgrade.

3. Getting a Magnuson blower kit for this truck.

I will be using HP Tuners to tune this truck and I will upgrade the fuel pump and injectors as soon as the truck makes it known I need them. When I swap them out I will be swapping for the size I expect with the blower on it. Hopefully it will support such a feat so I don't need to change them out twice.



Edit: Note, The link to the H2 Rear end is here:
https://www.chevyavalanchefanclub.com/cafcna/index.php?topic=146977.0

Thanks to the member who pointed this out to me! Now to look for a SAS that will work with this truck and use coil over shocks...
 
Update... I did end up buying an LQ9 out of a 2005 Escalade. I pulled it all apart following a rebuild book.

Next step for this motor is to figure out what rotating assembly I will be using with it. I plan to install a forged stroker setup intended for boost.
All ARP bolts/studs to strengthen its ability to hold together. Looking for a stroker kit that won't need me to clearance anything hopefully.

Still up in the air about forced induction. Not sure what the different Superchargers will support. I am currently considering remote mounting a couple of M122 super chargers or possibly just mounting a TVS 2300 in place of the intake. Should be able to push a bit of air through this setup.. 

I already have an H2 3/4 ton rear end I will be installing on my truck shortly. A blower won't go on the truck until I build up the drivetrain a bit.

Rodney

 
I'm excited about your build! Please keep updating! Does the stock computer work out of the box with the LQ9 or how are you handling that?
 
BainMan said:
I'm excited about your build! Please keep updating! Does the stock computer work out of the box with the LQ9 or how are you handling that?

The computer should be fine... Its the same computer, just different programs. When I add the E-Fans I can probably use the  '05's program since I have its computer and computer harnesses as well.

So I am currently researching two things...
Since I have the engine complely torn down I am researching the components for it first.

What stroked, forged rotating assembly to buy, which Cam, What to do with the heads. Have cathedral port heads on the engine now.
Need to go low compression because I plan to put 1 or 2 blowers on the truck in the near future.

Also loosely looking at options with SC. Will be going Roots/twin screw. Just not sure if going to go a top mount, replacing the manifold, or remote mount. If I go with two then I will go remote mount.

May decide to grab a 2wd 4l80E for my initial build and temporarily convert to 2wd so that I can support the power without having to upgrade the 4wd components right away. Thinking of doing a SAS swap up front and that can impact what else I get.

Rodney

 
Sounds like fun!  The LS motor is super easy to work on, btw.

For rotating assemblies, take a look at Texas Speed & Performance, as they specialize in LS/LT platforms.  For the heads, if you have 243 or 799 castings, just have them ported and a good valve job done. 

Since you do plan on F/I at some point, I'd shoot for around a 10:1 C/R.  With E85, and enough fuel supply, you could easily run 15lbs of boost without issue.

With your supercharger, are you buying a complete kit, or piecing it together yourself? 

As far as camshaft selection, what is your primary goal for this truck?  Do you still plan to use it as a truck, or more of a performance toy?  Are you opposed to running a stall converter?
 
I will have to look at the heads to get the numbers but I think they are 243 heads.

I may be doing the SC from scratch. I have a set of M122 blowers I am going to purchase that are special use items for dirt cheap for brand new units.

I also scored a Lightning blower for $100 plus the $80 for the intake plenum it needs. There is a kit that allows this to be bolted on the LS engines.. Would make my truck's blower be less than $1000. But the M122 blower is a more interesting unit. I may remote mount this and reuse the factory intake.

The end product of this truck is to be mostly a toy to play off road with.
It will get a large lift and some component upgrades to support this.

I am shooting for ~700hp for this build.

This will be the first engine I am building myself so I need some serious help with picking components. I will do all of the assembly myself so if I blow it up it will be much cheaper for me to repair... ;)

I would need to find a way to either run E85 or 91 Octane. I have to look at the tables to see if this is possible with this truck(I have the current program downloaded using HP Tuner). if it is then I need to rig up a flex fuel system. Or find the plumbing from a FF truck.

My initial intent is to build a stroker that will be durable and able to handle some boost. The M122 blower should be able to put as much air as I need to get close to my 700hp number with torque in the same ball park. I plan to upgrade components to 3/4 ton equivalents and already have a 3/4 ton H2 rear end I will be putting on shortly.

May temporarily install a 4l80E while working on this system in 2wd configuration just to get the bugs out before doing a drastic upgrade to the trucks suspension and driveline past the H2 rear end I already have.

That is my outline of intended gains at this time. I have the block disassembled at this time and on an engine stand. The heads are sitting on a pallet waiting for what I should do with them.

Rodney
 
The remote mounted M122s does sound interesting!

The GEN III aluminum block variant of the 5.3L can be bored to a maximum of 3.908", the stock bore is 3.78"
The GEN III iron block variant of the 5.3L can be bored to a maximum of 3.910".

Either of those would easily support your power goals, with the aluminum offering a significant weight savings.

Is E85 readily available in your area?  You'll have to let me know if your current ECM supports flex fueling.  I make custom flex fuel harnesses on the  side, so I can assist you on that front if you want.

In my Avalanche, I was running a fully forged 383, 239/247 @.6xx" @112 LSA cam, 1-7/8" LT headers, 3200rpm stall, ported 243 heads, ported TBSS intake, ported 90mm TB, and an LS7 MAF card with a custom CAI.  It made 390rwhp/400rwtq on 93 octane.  Now that I'm putting a Whipple on it, I'm hoping to crack the 600whp mark....
 
I talked with a coworker about going to a stroker kit on this 6.0 but he warned that the sleeves in the block now don't extend down far enough and the pistons will rock back and forth.

The engine was a high compression 6.0, or the LQ9 out of an Escalade that stock is rated not much lower that what you are saying you are running. Unless the LQ9 rating is at the crank and yours is at the wheels.

Would be interested in hearing how the Whipple charger does. Not sold on those because they are centrifugal and roots/twin screws are better for low end torque.

I have to do exhaust work etc yet which I am sure will help as well.

I was looking at a 408 or a 422 stroker, forged kit.
 
I'd check with a machine shop to get further clarification about the 6.0L stroker options, because they are done all the time.

Yes, the LQ9 ratings are at the crankshaft, whereas mine are at the wheel.

408 seems to be the more popular stroker choice. 
 
I just re-read your previous post and comprehended what you were saying about the Whipple.  It is a twin screw supercharger, and not a centrifugal.  For our trucks, you couldn't pay me to put a centrifugal on them, unless it was race only....
 
Ahh ok... I haven't really figured out what actual components I will use yet. Just trying to research as much as I can before I start working on it.

Sounds like I should be able to get some decent power out of this engine normally aspirated. I will know more once I have picked components and started assembling.

Rodney
 
On order:
Mahle 2618 Forged rotating assembly -28 dished for forced induction with ESP Armor finish ARP2000 rod bolts.

Will also order ARP bolts for the assembly of the bottom end.

Once the block is machined and returned I will assemble these components and will order the custom camshaft, timing gear set, oil pump, new covers and whatever else is needed to get the bottom end put back together.

Will be using aftermarket heads that have better flowing heads with larger valves and double springs already installed.

I have the lightning blower but I am not sure yet if I will use it. I may decide to go with 1 or two of these M122 STS-V blowers I found. Requires some custom fabrication but I am already putting one in my 3.6 equipped CTS AWD wagon. Which should allow enough head room for that car to be the fastest CTS AWD car in existance after doing some other upgrades to that cars fuel system and heads/cams.

Any of these STS-V surplus blowers will be mounted remotely similar to how a Turbo or a Centrifugal super charger is.  There is a kit to mount my M112 Lightning blower in place of the intake but I don't know if that will give me enough air for the power I can make. I MAY just install the Lightning blower initially to get it running with something the original drivetrain can still handle before looking at adding the other blowers.  The engine should be able to handle well over 1000 hp. I scored the Lightning blower for $100 for a unit that was only used on the prototype 2001 Lightning for 2 months while Ford tweaked the tune for the production truck. Atleast that is the story and the rotors look brand new... 

I will update the thread once I get a little further...
And yea I was going to buy an ATK high performance engine but when done, this setup should support more power and if I break something I will know how to fix it...
Not to mention that knowing how to build an engine from scratch isn't a bad thing...

Rodney





 
After talking to the machine shop I am likely going to have them put the rotating assembly and the cam shaft in my truck.

I will likely have the long block assembled by may it looks like. I am not in a big rush for it since I can't do anything with it for a little while yet. Probably won't actually install it in my truck until the fall.

Rodney
 
So I have an "Eagle" 408 Rotating assembly with "Armor" on it.

I have had people ask why I didn't just buy an engine for $4k and put it in my truck with a warranty... 

Well for what I am putting into this engine I would be spending $7k-$8k to support what I want to do with it. And I suspect since I am not a "licensed" mechanic such a warranty would be null and void.

Engine block has been cleaned and magnafluxed. I will be attempting to balance the pistons myself and at least get the total weight of the rods. The guy I am talking to at the engine shop told me they like to have the pistons within .2 grams of each other. Similar with the rods but I don't have the right rig to setup balancing of the rods.

I plan to have the engine shop return the engine to me as a "short block" and go from there. Basically I will still need to get some heads for it with the related other components (push rods, lifters etc)
Shooting for compression of 9.5:1 on this engine to support forced induction.

Have already mentioned I have a Lightning blower in my hands and will pick up some STS-V blowers that need heavy modification to get to work. Not expecting to mount the Lightning blower in the "normal" blower position if I am able to use it. Found a shop where the guy is installing some different blowers on top of the Magnuson intake "tub" as he calls it. The Lightning blower may be one of those.  The lightning blower will "only" be good for ~600hp but for the price I paid for it and add the cost of mounting it... Will be cheaper than the fuel system upgrade I need to power it. 

Since my rear end died I am also in the process of installing the H2 rear end to help put the power to the ground... I put a link to the thread I am using to base my upgrade off. Should go smooth.

Rodney
 
Do it correctly; do it one time. That means figure out your ultimate goal and put everything in to support that goal at the time of build. There will be a lot fewer headaches if you do it that way. If you think you will run E85 through a supercharger, size the injectors and fuel pump for that right up front. Spend time picking a correct blower cam as well. And in my opinion, sell off all the other blowers you are talking about, buy a TVS 2300 kit for the 6.0, and add it. You will get the best bang for your buck with the least amount of headaches. Whipples are fairly easily pushing over 750 hp through 5.0 Coyote engines in F-150s, but I haven't recently checked for details about them on GM engines. Magnuson was the go-to pd blower when I installed the MP112 on my Avalanche back around 2004.
 
Thanks for the suggestions. Thing is I can go either the lightning blower or the dual M122's for under $1000 without an intercooler... Not touching a TVS2300 kit for anywhere near that. Add another $1000 to get the intercooler setup.. Still not going to touch even a used TVS2300 kit for that.

The engine as I am building it will have a blower cam in it and will be ready to take a blower in it. Going to get the engine in the truck and up and running before doing anything else to it. Once I know the engine is running fine N/A in its new home and have any bugs worked out I will be upgrading the fuel system to support that 1000+ hp. If I do use the lightning blower it may only be temporarily to see what kind of power I can get with it before doing anything else. There is a guy in the UP of Michigan that builds a full adapter kit for the older eatons to bolt onto a Magnuson tub.  I have already been warned that the blower cam won't produce as great a power boost with the 408 as opposed to the original 327 in there currently. But should show significant improvement once I add the blower.

I may decide to go a different route down the road and if I do I can change it then. I kind of want to go in steps anyhow to get used to what I have. The M112 lightning blower should support a pretty significant power boost. I know I am REASONABLY safe with the stock driveline with the lightning blower. Other than the 14bolt rear I am currently ready to install. When I go to a bigger blower be it a 2300 or dual M122's I know I have to make some major changes to the driveline. At that time I will also be looking at installing a SAS front axle and do a 10" ish lift.


The Dual M122's should get me to over 1000hp.
 
batmanntexas said:
Rodney, what cam did they spec out for you?

Haven't yet... I am at the point I will be buying the cam though. The new guy I am now working with suggested that the single roller timing chain and gears from GM High performance are more than enough for my setup. He also has some stock heads that have been reworked that I will be grabbing from him. Ported, new double springs, new valves etc... He has a couple CTS-V's in his shop right now and an older trail blazer. So he doesn't JUST work on LS's.

This guy builds a lot of LSx motors and puts them in a lot of different cars so I think I found my local guy. He also works with the best engine machine shop so one way or another I should be good to go. Not to mention he has a dyno and does a bunch of tuning as well..

They should be starting to put the engine together this week and I will have the Cam and timing set ordered by monday with 2-3 day turn around.

Both the engine shop and this mechanic like getting Brian Tooley stuff... So we shall see what I get.
 
Finally got the rest of the components other than the push rods. Will get the push rods once assembling the engine is done. Got some cnc ported 243 heads with double springs on them. I hope to start assembling the rest of the motor this week. May or may not get the super charger setup to go on it. We will see where I am once I get everything assembled. I may just get this up and running without the super charger first because I need to upgrade some components in the system first anyhow such as the exhaust and fuel system.
 
Sounds like a good plan Rod (y)
 
Right now my truck is stuck in the back yard. I popped the front axle off before I pulled it out. I had brought the engine to the same garage my truck is in with the truck. (The engine it has now runs fine but uses coolant somewhere and with 280k miles I figured it was time.) Well the H2 rear end has an electric locker so I have to put 12 volts to it to lock the rear. Will try to hook that up later in the week and get it moved back to the garage. Back in school so my time is somewhat limited. Also waiting for a new windage tray that is made for a stroked engine. I spent the better part of 3 hours trying to modify the stock one and still hits. A new windage tray was only $70 so I figured that was a much better plan. Since I am in school right now I don't know when I will get the chance to install this engine once I have it put back together, May not be until the snow melts. lol
 
I haven't updated this thread in a while... I should be finished putting my motor together in the next month. finishing up my masters is putting a bind on my available time... However I do have a question... I don't believe the stock fuel system will handle the power I am going to be applying to my truck. Can someone offer some suggestions about how to upgrade my '03 fuel system to support up to 1,000 HP on E85?

Truck currently has stock 5.3 likely with original fuel tank and injectors. The new engine started out as a 6.0 Escalade motor out of an '05. It now has fully forged 408 stroker kit, BTR stage 3 Turbo Cam, CNC ported 799 heads with larger valves and double springs. I have some Jegs rockers with Trunion upgrades on them. I have been told the stock 6.0 injectors may not be enough to handle this engine let alone when I start putting boost to it. Initially it will be N/A but I will likely start out with an Eaton M122 blower on it and see where that gets me. If not where I wanna be then I will look at adding a turbo to it and moving the SC to a remote install so it would be a staggered SC/Turbo setup. Or just get a bigger SC. Havent gotten there yet. Just want to make sure the engine runs fine NA and finish upgrading the Drivetrain before putting a blower on it. May do the lightning blower up front because it will definitely help but won't really add that much power.

Also have a Lightning blower (M112) which I MAY put on there but that might not be worth the trouble for the little boost it will give on this motor. Unless I pair it with one of the M122 I have here. MAYBE that will get me up close to 1000 hp.. But again. Steps... I want to make sure it works fine as is before I go crazy. Will be looking to also upgrade the exhaust before any SC as well.
 
Well, nothing like reviving this thread... Had some RL issues crop up and had to put things on pause for a little while. Since the last posting I graduated with my Masters, Retired from the City of GR and have started working as a software engineer for another company. I work remotely now so I can be anywhere. I am in process of paying off High interest debt I acquired while finishing up school. But in the process I have been able to just not wake this project back up. Truck is at 295k miles and I used it to pull a large U-Haul trailer back up from Texas. I lived near Houston from about February until June. Moved back to Michigan and will likely be here for most, if not all, of 2023 as I finish paying off debt, get the next step accomplished in my truck accomplished and go from there.

So the engine is DONE and at the motor shop. I ended up having to move the engine parts to a storage unit last year and it got some rust on the top of the block so the Engine shop had to disassemble it, clean it up and reassemble it. Looks nice under wraps.

This Engine Lived life before as an LQ9 but now lives as a 6.6L Stroker. Has a high pressure oil pump, 799 heads that were CNC ported with larger valves and double springs. Using Trunion upgraded Rockers and Whatever pushrods the engine shop got for them. The Cam is a BTR Stage 3 Blower Cam. Not sure of details but I am told it should make SIGNIFICANT power at full boost.

Couple pictures of the Engine as it is today:

20221201_135841.jpg20221201_135848.jpg

Had it as a short block... $1500 to pull it back apart, clean it up and put it back together to this point.
Looking perty...

I will be moving through this month so I will not be putting my truck in to be done yet. I have plans for significant upgrades to go along with this to support the eventual ~900-1000 hp I expect to make with this puppy.

Along with the engine it will be getting a fuel system upgrade to handle 1000+ HP. They are installing with a single 525 pump and will upgrade later to 2x525 pumps prior to adding the blower. Want to get the lines in place since it will need a bigger fuel pump than stock just to run this engine NA. Might as well upgrade while the truck is apart. So it will get regulator and lines that will support 1000hp.

Transmission will be a 4l80E that will be redone with some better components to handle the extra power. Will match to a 3/4 ton Transfer case. Already have the H2 rear on it which is 4.10 gearing and will more than handle the power with its 9.5" gears. Like the electric locker too. I guess its a Semi Float rear but I shouldn't break it easy regardless. Will also look at doing other stuff such as Drive shaft loop(s) as needed and maybe an engine fire extinguisher system.

Will evaluate where we are when we get to that point. I really like the idea of a Whipple 2.9 in here though. Will include a snorkel when that gets added. May decide to go with an LSA blower, Magnuson 2.1+ or some other combination. I have time... Not in a hurry at this stage. Will likely be throwing on 3/4 ton front end components to help with the 8lug tires plus would be even bigger brakes than what is on it now.

Also need to consider what exhaust system to run with this. I am thinking Long Headers running to true dual 3" exhausts. With a blower and long headers I shouldnt have to worry about scavenging the exhaust so large exhaust sounds like would work better. Have not decided yet.

Will size everything to run E85 then decide what we will run when the time comes. I have been told by a couple shops that these computers don't handle "Flex fuel" stuff very well. I can get it tuned for either flex fuel or premium not both. If that is truly the case I may consider an aftermarket engine computer. I can always add a sensor and whatever I need later. Should be a fun truck to drive regardless. The Frame is solid but I have rust on the body around the normal areas. Real bad around the back door and rockers. Looking at it this way... I get it all worked out and the truck is junk? I just buy another truck and swap everything over. When I get my own house hopefully by end of 2023 I will likely pull the body off the frame and clean up the frame, put it back together and go from there. may do that before the blower gets added. See how things go.
 
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