What should I do with this CL find 6.0L LQ9 ?

[jjzepplin]

So I am scouring CL and find a 1998 5.3 with 170,000 miles, just the longblock. Lady says its 345hp. HMM. It has no pics so she sends me some. Now', I am not looking for and engine but she doesn't want very much for it. I thought I would go take a look as it might have good heads or who knows. I decide to buy it and take it home. It ends up being a 6.0. She had a box of parts that came with it like the air filter,exhaust manifolds, some bolts and a water pump and engine covers. I take a look at a sticker on the air filter and it says 2006 6.0. I look at the engine covers and the one on top says Vortec Max.
It has 317 heads so I pull one. This thing has flat top pistons and I can see the cross hatch in the cylinders still. I think it may be the 345 hp version. It has no intake or sensors or front timing cover. Timing chain has very minimal slack. The only thing I can find wrong with it is it has two bolts broken off in one of the heads for the exhaust manifold. The story was that it came out of a Dale Earnhardt P/U and the fella wanted more power so he bought a crate engine. She gave me the crate to load it in the P/U with. I pulled all the plugs and they are brand new. Looks like they may have fired a couple times. With just one plug in and on the compression stroke, this thing is very hard to turn over with a 1/2" ratchet on the crank bolt. So What do I do with this thing? Right now I am swapping a 5.7 and T56 into a 72 2wd Blazer. Do I swap em?

[AussieinNC]

Look on the drivers side of the block, towards the rear...there will be a casting number...post it and we can tell you the year origin of the motor...

As far as "Do I swap them"...its your choice...

But you will need a substantial amount of parts to get this LS engine up and running....

You would also be advised to go thru the engine and make sure its all good to go...LS vs 5.7 aside...it depends on your budget and end use of the Blazer....

[jjzepplin]

The casting number appears to be 12577184.

[AussieinNC]

LQ4 6.0l

2001 - 2007 (317 heads)

See this link for full engine specs (thanks Summit)

https://help.summitracing.com/app/an...4-engine-specs

LQ4 should have dished pistons...if you have flat tops, the engine may have been modified....post a pic of the top of the pistons...

Hope this helps...

[mongocanfly]

That casting number shows it being a LQ4....the 322hp version of the 6.0

[mongocanfly]

Ha...aussie beat my thhhiiis much...

[AussieinNC]

Originally Posted by mongocanfly

Ha...aussie beat my thhhiiis much...

Old drag racers never die...they just get better with age....

Hope you are doing ok....

[jjzepplin]

Yes. I do believe those specs say a dished piston. Upon further investigation, this engine has flat top pistons and the heavier duty rods indicating a 10-1 compression and a 345hp version of the LQ4.
"The Vortec MAX engines had higher compression ratios of 10:1 and included flat-top pistons for increase power output. The gear ratios were also altered to improve towing capacity, with a towing capacity of 10,800 pounds. While suspension and brake packages we’re available to most models, all MAX engine vehicles had thicker front sway bars, four wheel disc brakes, a heavier duty transmission, and a larger 9.5″ rear end."
https://chevytrucks.org/what-is-vortec-max/

[LS short box]

As for what to do here's my .02.
Replace the oil pump.
Judgement call on replacing the timing chain. They are pretty cheap.
Pull the other head and check all the lifters. Pull the cam and check for wear. Maybe replace the lifter trays since they are cheap.
If you have a machine shop near by have them mic the cylinders to determine wear. May have been bored since you can still see the cross hatching.
Depending on your budget maybe a small cam? Means new better push rods and springs.
Good luck with your project.
Maybe pull a few rod caps to check bearings for wear. Doesn't cost anything.
Pull main caps and check for wear? Only cost is new crank bolts.

[jjzepplin]

Thank you all for your replies. I have an LS1 in my Blazer now and was thinking of building this one in in the background slowly. I was thinking a cam for sure and I will inspect it further when I get a chance. I will post some pics coming up. I have built many a SBC and quite a few Furds as well as AMC and Mopar engines as I used to work for a rebuilding facility in Cali. I just never messed with an LS or the newer stuff past about 2000. I have a decent budget but no real plans as I just came across this one day. I really liked my 350 in my 66 Malibu as it had a real lopey cam so I may go big with this one. Not a "Thumper" cam but something that actually works. I have to have AC here in the South so that may not work out. As for being bored-I have heard of people pulling heads on these with close to the mileage, and seeing the cross-hatch. There are a bunch of engraved numbers on the pistons but the biggest one on all of the pistons so far is a big 5. I'll get the other head off soon and check it out. So is there a better stock head to run with flat tops or stick with these 317's?

[LS short box]

No idea about the "5" on the pistons. You may want to consider L92 heads but that means you will need a LS3 type intake due to the square port L92 heads.
Tons of LS6 type ported heads out there if want to keep the LS6 stuff you already have.
Your 317 heads are as good as they get for a stock head that work with your LS6 intake.

[clinebarger]

LQ4's & LQ9's have the same external parts & casting numbers, The Rods & Pistons are the only difference.

[jjzepplin]

I guess I could try my hand at porting with these 317 heads. I have to try to get the broken bolts out of one of them first. Do these blocks have an area of concern for cracking etc? I just don't see a reason to replace this one unless catastrophic damage has occurred. I can't find any real damage yet. Maybe there is a cracked piston under that other head. Maybe three broken exhaust bolts gave the computer bad readings and made this thing run like shot. I can only see a possible exhaust leak on one of the exhaust ports on the head but not the exhaust manifold. So maybe port the heads, big cam, hone the cylinders, new rings/ maybe forged pistons, new ARP bolts throughout. That should give me a real base to start with. Run that 5.7 hard knowing I have a good backup...

[LS short box]

A car buddy of mine runs a 6.0 in his 72 Nova. He did the L92 head swap and with a "medium" size cam it did 420 hp on the chassis dyno. I know not huge numbers but it has a good lope to it and it was a piece of cake to tune per the tuner. I think the cam was in the 230I/240E range. In my 68 C10 LS6 swapped I'm running Diamond forged pistons and Scat H beam rods. It's been bullet proof after 8 years.

[jjzepplin]

Did you install flat top pistons?

[LS short box]

On my buddy's car he had the lower compression pistons. Just a standard LQ4. On my LS6 the compression ratio is 10.5-1. My other hot rod is a 98 Wrangler with a LS6/4L60E combo. Stock rebuild. I have both tuned for the local 91 octane. Always run non-alcohol premium.

[aknovaman]

Are you ignoring the most critical point the OP made " this thing is very hard to turn over with a 1/2" ratchet on the crank bolt." ?

Could it be symptoms of oil starvation and other hidden issues? Disassembly will tell.

[jjzepplin]

IT IS hard to turn over. Of course, I would love to have even more compression but I think the 10-1 may be enough. Would 243's really work? Seems Like it might spit a plug out of the Aluminum head. I also may not be able to run a large cam do to interference issues? Could I just mill the heads a bit and get a big lopey cam?

[AussieinNC]

How long a handle is on the half inch ratchet?

Are both cylinder heads off the block?

Using a 15" breaker bar, you should be able to turn over the engine relatively easily if both heads are off of it.

If the engine is tight to turn with the longer bar...with the heads off, drop the sump off and check the bearings asap....look for blued rod caps....and metal in sump...

In my experience, the alloy heads on an LS engine will not spit out spark plugs even with turbo boost....

[jjzepplin]

I am using an old school Craftsman ratchet about a foot or so long. One head is still on the block. It pops a good exhaust signal when I rotate it with just one plug in each cylinder. With both heads off it turns ok. I am going to pull all the caps anyway just to be sure. Just looking at it though, I would venture to say that I could run it as is but I've come this far. I just don't know the history other than what 5 older guys drinking beer told me. HAHA.

[jjzepplin]

So I did a little work on the head that was off. I extracted the broken bolt by using a self centering Door hinge spring loaded bit thingy to drill the bolts or at least to get the bit centered. Dang those bolts are hard. Then I pounded an Allen wrench down into them and they broke right loose. This is the best hole I have ever drilled as far as bolt extraction.

[jjzepplin]

I did a little quick cleanup on that side of the engine and head to see what I was working with. I don't see any cracked pistons and the valves look like they are ok, just need some cleanup and some lapping. Seals look just a little crusty after removing the first two springs on the head.

[jjzepplin]

Alrighty, I got the other head off and things are pretty much the same as the first side. No broken pistons and the crosshatch is visible. The head gasket looks ok. I did however find 4 damaged push rods and rockers. Indiscriminate positions on the engine. I am thinking that the owner possibly had broken bolts in the heads and ticking noises so they replaced the engine. I am still going to go ahead and pull caps to inspect. I really want to run this engine stock. But if I have to go replacing all kinds of stuff, it will get some big lovin! Side note- I have heard LS engines have lifter ticking problems. Could it really be rocker/pushrod noises from the lifters not rotating the pushrods? Second side note- My 5.7 I am swapping in my Blazer right now has about the same mileage but was making no noises. Should I pull the covers and inspect? UGH!

[AussieinNC]

Re 5.7...

I always find it much easier to replace rocker cover gaskets, oil pressure switches and freeze plugs (especially the two rear plugs behind the flywheel)....

New engine mounts...

If front balancer seal is leaking now is time to replace it...check the balancer rubber is ok...

NOTE>>>>Apart from diamaeter, if you replace the balancer make absolutely sure the indexing of the keyway to the timing slot on the outer ring is the same on new balancer to the old one...there are different balancers !!!!!

If there is any sign of oil leaking from rear of manifold, now is time to r&r manifold and reseal it...

Your back will thank you in the future...

Re LS...

The lifter ticking noise is well known and there are lots of posts about it...new lifters, push rods and carriers will usually fix the issue...the damaged push rods and rockers is a big issue....post pics of the damage please.

This is looking more and more like an oil system failure...pump O ring to pickup tube is biggest failure point....pull the pump apart, clean up the inners and post a pic of the inners...

[jjzepplin]

Did some work on it today. I did not pull the oil pump apart but I did take it off. I am bushed so I will have to take it apart tomorrow. I did pull one cap on the crank and one cap on a rod. They both look pretty good. I will post some pics later. Dinner time right now. The push rod damage isn't really that bad, I just noticed it because the first one was so shiny. I looked closer and could see the out of round nature. I looked at that rocker and it too was worn the same way. Not tons of metal missing but I'll bet it made a noise. It's hard to pic up on camera.