Frost

iTrader: (45)

Not my choice for a boosted engine base..

beavis

iTrader: (15)

How does this core shift happen? Shouldn't this been caught when the motor was built? or did it happen under boost on the dyno?

Busy Mopper

iTrader: (4)

Holy **** id rage was the motor put into boost?

black98ws6ta

iTrader: (77)

It should, I would hope.

1toofastlt1

iTrader: (4)

will a ls2 block with ls7 sleeves bored and stroked to 440ci be stronger then that GMPP 454 block for boost?

Jontall

LS7 sleeves are no-good. You need to use Darton sleeves, pinned billet main caps.

93formto98T/A

iTrader: (28)

Does anyone have first hand experience with this? This is news to me.

buick_lsx

core shift happens during the casting/mouling/foundry process, whatever you want to call it lol...it would have/should have been seen before any work was ever done to that motor

i come from old buicks and this is a problem with the 455's...didnt think it was a problem on any new blocks though, especially something like this

98Z28CobraKiller

iTrader: (17)

You can see the pitting from the detonation on the pistons as well.

Mkelcy

iTrader: (3)

There is a LOT of fail in that thread. Apparently Gen 5 owners don't know the difference between a block and an assembled engine, don't know that boosting an 11:1 engine's not the smartest thing to do, don't know how to read the GMPP warranty which excludes "Damage caused by a turbocharger, supercharger, nitrous oxide, or similar product, which is not an approved GM Performance Part or Accessory," and think "building" a 1,200 hp boosted engine means bolting on a blower and then crying when something breaks.

jfg455

iTrader: (5)

I work as a GM tech (12yrs) and you really have to read the fine print of the warranties. It states if there is any aftermarket tune in the PCM or any type of device that increases the hp or tq output of the motor then the warranty is null and void. Period. We even have to snapshot the tune numbers in the PCM before doing any engine or trans work under warranty. Same goes with the GMPP parts. They understand that it is going into a hot rod but it wasn't built for any power adders. Just because the head guy states that it "should" hold up to a power level does't give you a green light to put a power adder on it. It was only designed to live in the enviroment and power level that it is deliverd as. They warranty it based on these power levels. It does totally suck that it lunched but the owner doesn't really have a leg to stand on warranty wise. on the flip side you can take a stock 5.3L, put a bad tune in it, and blow it up at 250hp just as quick. I hope all works out well for the owner in the end.

NASTYTRANSAM

iTrader: (12)

That sucks either way you look at it. I wouldn't wanna be the guy who told him "hey use this combo it will work"

Shawn @ VA Speed

iTrader: (3)

I went through 3 blocks to get a decent one for you. The new lsx blocks are horrible.

Shawn @ VA Speed

iTrader: (3)

exactly

Frost

iTrader: (45)

What's the process when you get a bad one? Does GM accept it back and send a replacement? Do you have to cover the back and forth freight each time?

ChevyChad

iTrader: (50)

I'd like to know as well. Also, seems like maybe it wont present itself until there has been machining done, or at least maybe it can be seen when magnafluxed? Does GM pay for the machine work/ magnaflux in that case as well?

NASTYTRANSAM

iTrader: (12)

Man, seems like GM performance parts needs to step up and make some changes if they wanna keep selling a product. If Shawn says they are not a good item then Im sure people reading this will probably think twice before buying there block ! Get in here rep and lets here your side LOL

Frost

iTrader: (45)

I'd think it would be during sonic testing

ChevyChad

iTrader: (50)

Sonic testing is the same as magnaflux isnt it? Just that you cant magnaflux non-Ferris materials (ie aluminum) so they have to be sonic tested. But since the LSX is steel (iron- whatever) it can be magnafluxed.

blue00ZZleeper

iTrader: (5)

IIRC the sonic testing is to actually check the material thickness and condition. We do this at work on some of the turbos we work on to check the casing. Magnafluxing is to check for cracks or imperfections in the casting process. Both have similar goals but I believe their different. Someone chime in if I'm wrong lol