What now?

[larry_g]

So I have a 66K mile 2014 1LE with the basic bolt ons (intake and headers) with a custom tune making about 420 rwhp at a local dyno shop. I've been contemplating some kind of boost for a while and lucked into a smoking deal on a Whipple 2.9 here and thus started my journey down this rabbit hole.

My tuner recommended heavier valve springs as he has seen the stockers float valves on minimal boost. As long as I was doing the BTR 660 valve springs, I also decided to go with a BTR stage 3 PDS cam, install kit, and CHE trunion upgrade. Just the basics without getting too deep.

When I pulled out the stock cam, the very first lobe looked like there was a chunk missing. It's like there wasn't enough material in the casting when they machined it but said eff it and used it anyway. Nice QC there GM. Anyway, at that point the heads came off so I could inspect the lifters.

The first lifter looked fine but a couple others had some noticeable wear marks on the rollers so I ordered up some Johnson 2110r lifters along with some more gaskets, a melling oil pump, and a new chain while I'm at it.

With the heads off, I pulled the valves and cleaned up the carbon deposits. The exhaust valve seats had a lot of build up and the sealing face of the valves looked like they had been taking a serious beating and were all pitted. Whatever, at this point I'm looking at some inconel exhaust valves and still undecided on replacing the intake valves as they cleaned up nicely.

I start cleaning the block and pistons and I stumbled across what is most likely a deal breaker for the life of this LS3...It looks like I have a crack in the #7 cylinder liner right at the thin point next to cylinder #5. I was using a mirror to make sure I had gotten all of the carbon cleaned up when I noticed it.

At this point I have already spent another 50% of the cost of the blower in supporting mods and it doesn't make sense putting any of it back together even though it was running fine when I started pulling it apart.

So what do I do now?

1. I have found where LS7 sleeves and blocks crack at cylinder #7, but it seems like a real anomaly for an LS3 to crack a sleeve. I should be able to find a reasonably priced used LS3 that is not likely to have the same issues.

2. Buy a built short block and finish what I started knowing it can handle any additional boost I throw at it in the future.

3. Sell off all my goodies, buy a crate motor, and leave it alone (for now).

[racesloth]

LY 6 truck block ($700-800 on CL or less if you are lucky) - bore to .30 over and summit forged LS pro pistons ($600 Weisco really) reassemble as a 370ci with your LS 3 crank and rods or add rods if you want and let that supercharger eat. Sell the LY6 Pistons rods and crank over at LS1 tech, sell your LS pistons and make some of your money back. You take a 100lb weight penalty with iron but it is stout and doesn't mover around. Enjoy the road! Many other options but will most likely take more money.

Or on CL (southern GA, Northern FL)
#24- Alum 6.2 4.065 bore, USED, very good shape. $1300 LS3 or L96 truck
#15- 6.2 LSA, 4.064 bore, USED, very good shape. $1600 LSA block with piston squirters

[ttshovel]

What he said , do not use that block! I picked up a ly6 shortblock for 850 off fb. This thing has seen way more abuse and power than you're looking to do. I'd be looking into the same or as stated above throw rods/pistons in ot and forget about it

[larry_g]

Time to learn more about the LY6. Thanks!

[Big Biscuits]

Same here. $500 for a LY6 recovered from a fire. Intake was melted and accessory drive was melted. Pulled off all the bad parts and got a pretty good short block. It will be a stroker motor though.

[Big Biscuits]

FYI, ly6 and l96 are basically the same. L96 is newer and flex fuel.

[UNRIVALED SS]

I’m curious about a few particulars for that motor.
What temp did it commonly operate at?
What oil did you run in it ?
How often was it changed?

[larry_g]

Daily driven in all weather, except accumulated snow. Always let it warm a bit before rolling off and light load/throttle until it's up to temperature. Mobil 1 or equivalent every 3-5,000 miles.


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[larry_g]

Right now looking very seriously at an LSA based build from Katech.

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[Greenhornet2]

cheapest route is probably what they are saying. Easier route buy a short block done. Stroker If you like. My plan is a stroker if my block fails but I am not sure which route I will go block wise. Already added 80lbs with the whipple, then another 100lbs for the iron block I don't like. You don't need an iron block if you are going to run that whipple as it will peak around 900WHP anyway. I may go TT if I damage my block and go iron for 1000-1100WHP but I may not I do like being able to get some traction on the street. Rabbit hole is deep here my friend.

[larry_g]

Originally Posted by Greenhornet2

Rabbit hole is deep here my friend.

Yeah it is. I'm debating between a quality build that I'll likely never have to mess with again, except add fuel and boost, and a budget build that could see me working on it more than driving it while I'm not get any younger.

At some point it's worth paying for peace of mind.

[Batmanntexas]

You can have peace of mind on a budget build as well, so don't let that stop you. Use quality parts, pay attention to the details during reassembly, and get a great tuner to tune it all, and you will have a long time of trouble free operation (outside of operator induced maladies.)

-Scott

[AGP Turbo]

As everyone is saying, iron 6.0 block for sure. But I'd say just buy a Thompson fully forged 408 with the warranty. They have stood behind that warranty for a couple of our customers and that's pretty dang unheard of in the performance world. That way you have big displacement, forged everything, and a warranty to back it all up. Assemble it with your stock heads and cam/valve springs of your choice and now you have an engine ready to make 1100whp/ 1100wtq if you ever want. Then we'll give you a fat discount on a dual fuel pump, TT package

Now. That cyl looks to me like it was cracked from bad tuning. If the piston is also damaged (cracked/melted/detonation marks) then that pretty much means it's for sure. Anyone who sucks so bad at tuning that they ruin your N/A engine, please for the love of god don't let touch your boosted engine.

[BAD DAB]

Originally Posted by AGP Turbo

As everyone is saying, iron 6.0 block for sure. But I'd say just buy a Thompson fully forged 408 with the warranty. They have stood behind that warranty for a couple of our customers and that's pretty dang unheard of in the performance world. That way you have big displacement, forged everything, and a warranty to back it all up. Assemble it with your stock heads and cam/valve springs of your choice and now you have an engine ready to make 1100whp/ 1100wtq if you ever want. Then we'll give you a fat discount on a dual fuel pump, TT package

Now. That cyl looks to me like it was cracked from bad tuning. If the piston is also damaged (cracked/melted/detonation marks) then that pretty much means it's for sure. Anyone who sucks so bad at tuning that you ruin your N/A engine, please for the love of god don't let touch your boosted engine.

What would be some indicators of having a bad tune? (Without tearing the motor down)