Had to go 0.065 over LQ4 6.0 block =11:1cr 376" for less than $1000 all day build
06-26-2019, 08:38 AM
#1
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0.065 over LQ4 =11.8 compression 376ci" for less than $1100 daily driver 
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Last edited by stockA4; 11-12-2021 at 09:08 AM.
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Rickys2003svt.cobra (03-02-2020)
06-26-2019, 09:56 AM
#3
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10-27-2019, 12:43 PM
#8
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Guys I'm finally getting around to building this thing!
Here's some background on the block.
It's a 2001 lq4 that lived 282,292 miles before it exploded. It was making noise and the owner thought it had a bad lifter, it did not, The #7 piston appears to have got loose on it's pin and it finally came apart while pulling a trailer. It's going to have a chance at a second life in our work beater 2002 camaro that currently has a 4.8 in it.
The plan for the setup.
The 6.0 will get the same Ls6 Intake, stock exhaust manifolds and Y with magnaflow muffler, and stock verter 4L60e w/2.73's behind it. So we are going to start very small with the cam. I will probably just re-send the comp 212/218 115+0 from the 4.8 to get it started and then a little more agressive down the road after I put some miles on it and break it in. This car is a 100% year round daily driver and so big big tourqe under the curve from idle to 4800 (that's where it's going to peak anyway lol) is really all I'm after to start with for this one, though the engine should be strong enough with decent compression and able to take a donkey size bumpstick without complaint later on down the road if I ever want to shove one in and re-gear it and go drag race it.
The plan for Getting the shortblock fixed.
I'm taking the block to the machine shop tomorrow for an overbore to fix the damaged cylinder wall on #7 where the rod bashed it up. I'm debating having them replace the cam bearings as well as they will only charge me $55 plus the cost of the bearings to do so though I have heard I am better off leaving them alone if the cam I plan to use still spins smooth and freely with the old ones. Let me know what you guys think about that. I already have a good stock 24x 3.622 stroke crank and press fit rods I want to use with the new pistons and rings as well as a nice set of notched #853's from a 99 Trans-Am to top off the short block.
My target is a static compression ratio of 10.75-11.1 and a maximum dynamic compression of 8.7-8.9 depending on where the cam ends up and where the Pistons end up, head gaskets, ect.
I'm hopeful that a .030 or .040 overbore will fix the damage so I can just use the the ws6 store drop in 6.0 pistons (do they have flat top press fit still?) or something else budget like the speed pro line that summit sells. Basically I want the cheapest press fit flat tops I can find for this thing. If it has to come out farther than .065 I wonder what other budget options I would have besides some low mileage ls3/l92 take out slugs (already on rods hopefully). Of All the cheap flat tops I can find, the biggest oversize I see is 0.040 so I'm crossing my fingers that Is as far as it will have to come out.
Here's some background on the block.
It's a 2001 lq4 that lived 282,292 miles before it exploded. It was making noise and the owner thought it had a bad lifter, it did not, The #7 piston appears to have got loose on it's pin and it finally came apart while pulling a trailer. It's going to have a chance at a second life in our work beater 2002 camaro that currently has a 4.8 in it.
The plan for the setup.
The 6.0 will get the same Ls6 Intake, stock exhaust manifolds and Y with magnaflow muffler, and stock verter 4L60e w/2.73's behind it. So we are going to start very small with the cam. I will probably just re-send the comp 212/218 115+0 from the 4.8 to get it started and then a little more agressive down the road after I put some miles on it and break it in. This car is a 100% year round daily driver and so big big tourqe under the curve from idle to 4800 (that's where it's going to peak anyway lol) is really all I'm after to start with for this one, though the engine should be strong enough with decent compression and able to take a donkey size bumpstick without complaint later on down the road if I ever want to shove one in and re-gear it and go drag race it.
The plan for Getting the shortblock fixed.
I'm taking the block to the machine shop tomorrow for an overbore to fix the damaged cylinder wall on #7 where the rod bashed it up. I'm debating having them replace the cam bearings as well as they will only charge me $55 plus the cost of the bearings to do so though I have heard I am better off leaving them alone if the cam I plan to use still spins smooth and freely with the old ones. Let me know what you guys think about that. I already have a good stock 24x 3.622 stroke crank and press fit rods I want to use with the new pistons and rings as well as a nice set of notched #853's from a 99 Trans-Am to top off the short block.
My target is a static compression ratio of 10.75-11.1 and a maximum dynamic compression of 8.7-8.9 depending on where the cam ends up and where the Pistons end up, head gaskets, ect.
I'm hopeful that a .030 or .040 overbore will fix the damage so I can just use the the ws6 store drop in 6.0 pistons (do they have flat top press fit still?) or something else budget like the speed pro line that summit sells. Basically I want the cheapest press fit flat tops I can find for this thing. If it has to come out farther than .065 I wonder what other budget options I would have besides some low mileage ls3/l92 take out slugs (already on rods hopefully). Of All the cheap flat tops I can find, the biggest oversize I see is 0.040 so I'm crossing my fingers that Is as far as it will have to come out.
Last edited by stockA4; 10-27-2019 at 04:34 PM.
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Ls7colorado (10-28-2019)
10-28-2019, 12:53 PM
#12
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How deep would you say the scratches are? You might be able to hone them out.
10-28-2019, 01:06 PM
#13
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Rickys2003svt.cobra (03-02-2020)
10-28-2019, 01:41 PM
#15
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.065 is a lot of boring. Not sure that's possible, but I know the iron blocks can handle much more than the aluminum blocks. An LS-savvy machinist would know for sure.
10-28-2019, 06:30 PM
#17
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I dropped off the block after lunch today. The machinist thinks it should be ok with an overbore but of course we won't know until he starts cutting. I'm really hoping for 0.030-0.040 will be enough but 0.065 would be ok I guess lol
10-28-2019, 10:37 PM
#20
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