ZONES89RS

iTrader: (25)

Just see allot of .060 over slugs for sale and i didnt think the LQ4/ block would take that, am i completely wrong or will they do street duty after that much id removed from the cylinders?

My old GEN Is i used to build would go .080 but they had some meat in the blocks cylinder area.

bww3588

iTrader: (49)

i went .030 over, and after that the sonic test still showed plenty of meat left. I wouldnt balk at .060 over.

AqudaleSpeed

I'd say your safe. The manufactures wouldn't sell them if they were a liability.

I would go smaller if you have the choice, or have any future plans for the block, after 0.060" most people junk blocks for street applications.

Jon@HKE

Depends on the block, some go .060" and some don't.

AqudaleSpeed

Are there certain years or serial #'s that can't go 0.060".

Just wondering

ZONES89RS

iTrader: (25)

Probably like the old Gen I sbc then, pre 86, they had core shift issues, perhaps the Gen iii/IV do as well on some blocks on a given day of casting. I figured they would go .060 but seeing so many sell .060 and even .065 slugs I was pretty much without a doubt, I like STD bore if I have a choice.

AqudaleSpeed

Alot of times you can just get a clean up hone and keep the stock bore depending on the condition of the block and your intentions.

Kwikcad500

Can you share the sonic test results? I only went .005 over on my 400,000 mile block for future overbores and you could still see the cross hatch in the cylinders. The block cleaned up perfectly @ .005 over

ZONES89RS

iTrader: (25)

The factory low tension oil rings compared to the older SBCs usually result in minimal bore wear, another plus over the older GEN I/II.

Isolde

iTrader: (4)

Core shift in a sand casted SBC, sure. But the '01-up LQs, never. Lost foam had a few issues, but the pre-'01s should be avoided anyway. By '01, all the LSx casting was SPM, which means NO core shift, ever.
The rings may be lower tension than the SBC, but you're giving that too much credit. Most of it has to go to the PFI. Look how the TBI engines tripled the bore life with no change of iron or rings. Then TPI, then the LTx, then the Vortec, then the LSx. Ever more precise fuel control, ever less bore wear.
Excess fuel washes the oil off the cylinder walls, and that's when wear happens.
The LQ has plenty of iron for a 4.080" bore at the stock 345 HP level. The more HP you want, the less the overbore should be.

ZONES89RS

iTrader: (25)

Seen the vortec and TBIs have a ridge so bad at the top of the bore the slug would not come out, still have not seen a LS like that yet.

bww3588

iTrader: (49)

I have an iron 5.3 with a pretty hellacious ridge. But its only a carbon ridge. Its got close to 200k on it tho. The rings were fried cause the entire crank case and rocker arm area on the heads is covered in a layer of carbon.

Isolde

iTrader: (4)

Point taken, I've seen the wear ridges. In TBI, not in '96+ Vortec. But the LQs are better iron as well.