Boosted LS1

I've come across a new block that's nicely bored and honed but the boring isn't central in the liners. So, either the liners have been fitted incorrectly or it's been bored off centre. It shouldn't be like this but I'm told it's normal which I find hard to accept.

It's so bad that the liner is 4 mm thick on one side and 2 mm thick on the opposite side. So assuming the liner's supposed to be 3 mm thick It's lost 1mm/.040" on one side.

Is this going to cause issues on a track focused turbo build and has anybody come across a similar block? Thanks.

99 Black Bird T/A

iTrader: (4)

Texas Speed has mentioned in the past that some of the GM blocks are off blueprint spec by a fair amount. I think Texas Speed has a half million dollar state of the art CNC machine for fixing issues with blocks like that. Basically, the block is scanned and digitalised and then operator can use the CNC machine to fix the issues. Texas Speed might be able to help probably worth calling them to discuss.

Boosted LS1

^ Thanks. I'm in the UK though. Do you happen to know if people use the blocks as they are or if they've been installed into cars by GM? I'll contact Texas Speed in a moment.

ATK Engines

iTrader: (1)

We see it all the time unfortunately. Some are ok for a stock LSA build, but we will go through a dozen to find one good one for a built LSA or charge to have it reworked.

Boosted LS1

^ Thanks. I never realised it was this common. I've never seen a block like this and am surprised GM didn't rectify this. I want 700-800 hp from this build.

Jimbo1367

I bet this is why MAST Motorsports uses LS2 block vs LS3s now.
Its too damn bad GM couldn't get their **** together

99 Black Bird T/A

iTrader: (4)

With new aluminum LS2 blocks costing around $1,265, new LS3 blocks costing around $1,902 and new LSA blocks costing around $2,561 that probably helps control cost as well. At $2,561 for an LSA block, GM ought to have those things very close to spec in my humble opinion.

it's seems to me that the GM machining / blueprint spec on the LSA block should be very good.

Boosted LS1

Didn't GM issue a release to say these LSA blocks were within design specification? Personally I can't understand why they didn't correct the tooling to get the casting cores in the correct place. It's only a mm out of spec. For a giant like GM this would have cost peanuts. I cast products and understand where the GM process seems to have gone wrong. I don't understand how some blocks are correct yet others are wrong. The same casting process should yield the same results across the board.

G Atsma

Multiple lines are used to make these blocks. ONE of those lines' tooling got out of spec...

Bazman

Yep, that block line was controlled that day by Pedro the porcelain etching champ. He was bending over the machine when sudden cramps hit from the Rings Around Uranus chilli cookoff the night before. By the time he got back from the *******, well the hole line of blocks had also taken a dump. TQM at the far end were down wind so they had their backs turned hacking into the filings bin and missed the entire run.

G Atsma

And THAT is as legit as it gets, folks! And you heard it here first! Meanwhile, back at the foundry....

Boosted LS1

Where Homer Simpson's in charge of casting and quality control. :-)

G Atsma

That's only on better days.... lol

Bazman

Spider Pig fills in for Homer