GM LQ4 rebuild

Greg

Make RME Rockcrawling Again!
Admin
I found this engine locally for $800, a guy had bought a older Chevy truck with this LQ4 swapped into it and it had (apparently) been a recent build, with only 12 miles on it... but things went south with the engine. It has some awesome upgrades, like the A-Team Short Fab Intake with massive injectors, 92mm Holley Sniper throttle body, etc. It has the factory 317 6.0 heads, but that's about all that was known. The PO didn't know anything about the build, camshaft, internals, etc. He claimed it had been ran on a dyno and made 500 HP at the crank. :D🇺🇲

It was running and I was able to listen to it before it was pulled and it sounded healthy, but terrible.... a definite knocking sound, not a rod but more cam like. The PO believed it was a cam bearing and I agreed with the assessment. We made a deal and he started pulling the engine.

Once it was home, I started tearing it down. The PO kept the valve covers, the valley pan, flex plate and had unbolted the intake. Before pulling anything, I grabbed the rockers and 1/3 of them were LOOSE, not a little.... but a lot. Way more play in them up & down then there should be. That was the first sign of issues.

Someone used a lot of silicone on the gaskets... which isn't really needed. I thought that was odd. I used hardly any on my L33 build and it has zero leaks. There was also a lot of trash and junk sitting in the external head bolt valleys.



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I believe its a 2006 block, based in the numbers cast into the passenger side of the block. Looks like 'F236' with the last number designating the year.

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Was able to get the lifters out (all but 1, its STUCK!) and inspected them.... again, about 1/4 of the lifters had the rollers chewed up. There was a definite cam issue going on! The cam looked to have been walking around and tearing up the edge of the lifters.

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Pulled the heads off and was surprised that there wasn't much crosshatching on the cylinders. There is no cylinder ridge at the top, but I'm not surprised as these blocks don't wear much from my experience. Pistons look new-ish, but I have to question the '12 miles' on this build. The pistons to look like standard dished LQ4 pistons.

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The timing chain was super loose, had WAY more play in it than it should. The torx bolts for the cam retainer plate were stupid tight.... I took a torch w/ rosebud tip to the bolts and block hoping the heat would loosen them up. Got 2 out of 3, then the last one stripped out. I ended up having to weld a nut to the bolt to get it out!

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I started to pull the cam out and it got hung up within the first 2-3 inches.... and I could hear something loose, rattling around. I looked into the block and could see a cam bearing floating around on the cam, getting hung up on the other bearings! o_O:skeptic: It took some effort to get the cam the rest of the way out of the block. Once pulled, I saw that the lobes were pretty messed up.

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The cam had a part # printed on the end... 31824100. Which a quick Google search turns this up.... it was a Brian Tooley Racing Stage 3 cam!!! 😭 - https://briantooleyracing.com/btr-camshaft-gen-3-4-truck-stage-3-v2-btr31824100.html

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So here's where we're at now.... I need to pull the crank, rods & pistons tomorrow.

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The plan is to have a machine shop go thru the block, clean it all out, install new cam bearings and go from there. The cam and lifters went into the trash, as did the one-time-use head bolts.

I would like to make some upgrades, the 317 heads have pretty large chambers, so lower compression. If I can find some decent 4.8 or 5.3 truck 243 or 706 heads to bump up the compression. I wouldn't need flat top pistons if I do that. I may keep & run the aluminum intake, since I have it, but it's probably not the best option for an engine that should be focused on torque.

Not sure what cam I'll run, but want something better than stock for sure. Perhaps another Brian Tooley Racing Truck cam?

I'll finish the engine off with either a Camaro water pump, balancer & accessories for a little more clearance over the truck parts at the front of the engine.

500 HP will be more than enough, but with a head upgrade bumping up the compression a little more, the right camshaft, 1.8 ratio rockers & that intake.... it should be getting close to the 550 HP range. 🤪😍
 

UNSTUCK

But stuck more often.
Love watching these builds. Too bad it was so bad off and a waste of good parts. Hopefully you got a good enough deal on it to cover the new parts.
 

Greg

Make RME Rockcrawling Again!
Admin
Love watching these builds. Too bad it was so bad off and a waste of good parts. Hopefully you got a good enough deal on it to cover the new parts.

I love LS engines! Feel a lot more comfortable with them now after my 1st L33 build and have always wanted to build up a 6.0l.

I think I got it for a good price, $800 as is. That intake, throttle body and injectors are probably close to $1000 when you add it all up. Another cam & lifters will be $400-500. 243 heads around $300-400. Still, for the kind of power you get it's not a bad price.
 

Greg

Make RME Rockcrawling Again!
Admin
I've never been an engine guy but after watching your camino builid and now this I'm starting to want to tinker with engines more...

I think its fun to build an engine up exactly how you want to! The LS engines benefit from such minor changes and there are so many factory variation that you can upgrade them for pretty cheap. Plus the aftermarket support for them is huge!
 

RockChucker

Well-Known Member
Location
Highland
I think its fun to build an engine up exactly how you want to! The LS engines benefit from such minor changes and there are so many factory variation that you can upgrade them for pretty cheap. Plus the aftermarket support for them is huge!
Agree. I'm excited to fire mine up and see how it is. I ended up with about a 10.5:1 compression with flat top pistons and 823 heads off an L92. They flow huge so it should really wake up in the higher RPMs....really sounds like your plan will end up at similar power as what mine will be (well is I guess....just need to finish it up and fire it).
 

spaggyroe

Man Flu Survivor
Location
Lehi
Historically, I haven't been Mr. Chevy, but I'll fully acknowledge that the LS engines really are that good. I loved the 6.0 I had in my buggy, and I wouldn't hesitate to put another in a project.

I love the build Greg. :cool:
 

Greg

Make RME Rockcrawling Again!
Admin
I'm going to plan on swapping out the aluminum intake and install a TBSS intake. The TBSS is a newer style truck intake, so it sits higher, which could be an issue with hood clearance, but I think I can get away with it. It will work better for my needs of having an engine focused on building torque down low, rather than at higher RPM's. The good thing about the TBSS intake is that it does both, very well!

Hopefully I can get some good money out of the aluminum intake, so I don't have much out of pocket costs.

I can piece together the intake, injectors & TB or I can buy a complete TBSS swap kit from Glenns Auto Performance for $450, but they're currently sold out. - https://www.glennsautoperformance.c...w-tbss-intake-manifold-w-fuel-rails-injectors

GAP also has a great FAQ about swapping a TBSS/NNBS intake onto an older engine. - https://www.glennsautoperformance.com/pages/intake-faq

I can find the intake itself on RockAuto for $140, but its bare, without injectors, fuel rail, TB, etc. I think i can run the injectors and fuel rails from the fabricated intake on the factory TBSS intake. And the Holley Sniper TB will work with it too. So that's my plan.- https://www.rockauto.com/en/parts/acdelco,12580420,intake+manifold,5536

This, combined with a set of 5.3 heads and their compression ratio bump & a good cam should make for a healthy engine with plenty of power down low... and up high.
 

Greg

Make RME Rockcrawling Again!
Admin
Bummer about the problems but love the progress. Taking notes for future reference.

I'm not too worried about the issues, so far they're minor.... it does sucks that bearing issues took out a very nice aftermarket camshaft! But I bought it knowing it had issues & needed work and IMO the price matched. Seems like stock, running LQ4's are usually around $1500-2000.


Historically, I haven't been Mr. Chevy, but I'll fully acknowledge that the LS engines really are that good. I loved the 6.0 I had in my buggy, and I wouldn't hesitate to put another in a project.

I love the build Greg. :cool:

Awesome! I've put a lot of miles on many different 6.0 trucks, personal and work.... I think they're great engines for a 4x4!
 

Greg

Make RME Rockcrawling Again!
Admin
I.M.O., they're pretty damn hard to beat. What are your camshaft plans?

I'm honestly considering another Brian Tooley Racing Stage 3 cam, same one that was in it. It sounded awesome, looks like it makes power from 2500-6500 RPM and has a very flat torque curve.

https://briantooleyracing.com/btr-camshaft-gen-3-4-truck-stage-3-v2-btr31824100.html

218/224
.553/.553
110+0


They recommend 2500-3000 RPM stall torque converter, which I'd plan on anyway so I'm not pushing thru the brakes. I'd shoot for 2500 RPM with this thing.

Here's a power graph of a 5.3 with this cam... I believe a 6.0 would be similar, with torque coming on sooner and everything (HP & TQ) else up a bit higher.

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Here's some sound clips of the BTR Stage 3 truck cam at idle...

 

TurboMinivan

Still plays with cars
Location
Lehi, UT
I'm honestly considering another Brian Tooley Racing Stage 3 cam, same one that was in it. It sounded awesome, looks like it makes power from 2500-6500 RPM and has a very flat torque curve.

It might surprise you to learn the BT Stg3 cam gives up torque from 4000 rpm on down, just to squeeze out a few extra horsepower at 6000... even on a 6.0L engine. Here is a broader comparison of the stock cam vs BTS1 vs BTS2 vs BTS3:

(skip to 5:17 for the 6.0L results)
 

Greg

Make RME Rockcrawling Again!
Admin
More progress on the engine, pulled the pistons & rods, then the crank. I was surprised at the amount of sludge in the oil pan and the amount of metal flake & material in the oil pan. Not to mention all the little roller bearings that were spread all over! The sludge also doesn't add up with the story of '12 miles' on this engine that the PO claims.

The rod bearings and crank bearing has all been beat up by the metal, but the crank itself isn't scarred up. I mentioned the one lifter that was stuck, it had to come out thru the bottom. The roller had come apart, spreading it's little needle bearings all over inside the engine.

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Also, someone forgot to put the circlips on one of the rockers! :skeptic: I'm assuming they have been upgraded with brass bushings and someone had a couple extra parts.

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I have some parts left over from my L33 build that I can use on this engine, a double roller timing chain & a new timing cover.
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