Rich2342

iTrader: (1)

I posted another thread last month on my recent damaged LS7.

Motor has been pulled. Not too bad overall.

-No metal in the pan
-Rods and Crank unharmed
-Block is intact except for the 7 hole and the piston pictured.

I am not looking for a new forged block or high buck fix.

What is my best remedy if I get stock forged pistons and reuse the rest? What are costs for machine/sleeve etc???

Never been through this before.

jayyyw

It can be resleeved if the liner hasnt been compromised, IIRC. that will be your cheapest option. Add a set of forged pistons for the stock rods, send your rods to get clearanced and recoated to Calico, and keep the stock crank. This will be the cheapest option but your weak link will still be the block, as the LS7 sleeves can't take a lot of detonation/cylinder pressure.

Steve - Race Eng

iTrader: (1)

That block is history. Don't waste your time with this. Blocks like this I replace with re sleeved LC9 5.3 aluminum blocks.

Jimbo1367

Well that’s final.

Rich2342

iTrader: (1)

Can you elaborate for my understanding?

02EBC5Z06

iTrader: (1)

Steve will probably verify with this, but I know in his experience.. Sleeving an ls7 block like this is a crap shoot. You could have the sleeves removed and down to the liner, but most likely the block is compromised to where you wouldn't/shouldn't/possibly couldn't resleeve it.

pdxmotorhead

In general, if you can find 1 good engine builder that can do the re-sleeve right in a average city,,, you've found a unicorn.
The Dirt track guys usually know who he is.. But it is not "cheap" 200 bucks plus per hole if he likes you.. And be prepared to wait. Good builders are busy..

I did a 2.0 Cosworth aluminum block twin cam a couple years ago for a midget, builder had to weld the side of block shut after the driver over revved it and made a 3" window in the block. Then sleeved all 4 holes, IIRC it was about 5K when done.. Its happily spinning 10K rpms on dirt tracks again...

Steve - Race Eng

iTrader: (1)

Any more than one short crack in a block, the block will be cracked behind the sleeve, results in the block cracking after welding. Heat, weld, reheat, vibratory stress relieve on cool down and they still crack when the sleeves are installed. I've repaired dozens of these blocks. The material these and most other stock factory blocks are cast from is 319 aluminum. Around 17% silicon, very brittle which is why they crack in the first place.

grinder11

iTrader: (1)

The 319-T6 aluminum is an inferior alloy to the 356-T6 alloy. The old, original ZL-1 427 BB Chevy blocks from the 1960s, the aluminum BB Chevy heads, the C5R block and heads, and I believe the LS9 block and heads are all cast from 356-T6 aluminum. The small amount of $$$ per unit saved by the damn bean counters is ridiculous. All the GM aluminum stuff should've been 356-T6. If it all would've been invented in the 1960s, it would be.

Steve - Race Eng

iTrader: (1)

It's not just GM using crap to cast their blocks. Ford Coyote blocks and many foreign blocks, BMW and Audi for instance are cast from hyper eutectic alloys similar to 319. The only factory blocks I work on that are cast from decent aluminum are the 5.4 5.8 Ford, Dodge Viper and some Honda blocks. A fellow once told me the reason 319 is used is because sand is cheaper than aluminum!

Brent66

I was wondering if this is repairable or not. I was thinking the block is scrap.

G Atsma

You would be thinking correctly....

Tommy42088

Jb weld and sand paper will do the trick, maybe a few pieces of bubble gum

Ls1Rx-7

iTrader: (4)

youre forgetting the popsicle sticks and duct tape.

B52bombardier1

Duct tape my friends . . . duct tape.

Rick

Che70velle

iTrader: (6)

Brent that block is garbage. Toast. Done.

Tommy42088

How the hell did I forget the duct tape, most important one