what do you think about this case?

[C_T_V]

One of my friend has a problem in piston No 8, and he think to change all pistons to Ls3 flat pistons + change the crankshaft also to 6.2
his engine L76 and already cammed
any suggestions? :uhm:

[G8 GT V8]

Your friend needs to get google happy and do more research on the differences between the LS3 and L76, but I will note a few show stoppers below:

First off, the 6.2/LS3 achieves the additional displacement over the L76 by having a larger piston bore:
LS3 = 4.065 inch bore
L76 = 4.000 inch bore.

This means that an LS3 piston will not directly fit in the L76 block. It is my understanding that the L76 block cannot be safely bored/machined to fit the LS3 piston in it, so no dice on putting LS3 pistons in his L76.
As a side note, my L76 has flat top pistons, so it would be interesting to see what the pistons look like in your friend's L76.

Lastly, the LS3 and L76 both have a 3.622 inch stroke, so putting in an LS3 crank in the L76 will not achieve an increased displacement of 6.2.

If your friend wants an LS3, his best bet is to order a crate motor or try to find a gently used one that has been pulled from a camaro SS (manual trans mission, because the Camaro SS autos are L99 engines which are still 6.2L but have variable timing and active fuel management).

[Crazy Paul]

Lastly, the LS3 and L76 both have a 3.622 inch stroke, so putting in an LS3 crank in the L76 will not achieve an increased displacement of 6.2.
LS3 pistons onto either crank would both achieve 6.2 displacement (on paper), but only LS3 pistons onto LS3 crank would preserve the internal balance of the engine. The showstopper is the diameter of the cylinder liners & very limited overbore potential in the L76.

[C_T_V]

Thanks for replying
I know there is a different between ls3 and l76 bore and we have to port it.
Here we can't find a clean and good condition LS3 block
And if it's available it's expensive arround 4000$ And the used Camaro engine around 6600$ :(
So can we find stock LS3 end bottom in USA more cheaper?

[C_T_V]

LS3 pistons onto either crank would both achieve 6.2 displacement (on paper), but only LS3 pistons onto LS3 crank would preserve the internal balance of the engine. The showstopper is the diameter of the cylinder liners & very limited overbore potential in the L76.
Yes we plan to change the crank to avoid balacing issue, but we are not sure about the block if it can handle porting and is there any way to change the sleeves to 6.2?

[Crazy Paul]

Yes we plan to change the crank to avoid balacing issue, but we are not sure about the block if it can handle porting and is there any way to change the sleeves to 6.2?
Not porting, it's boring....and no the L76 sleeves wont handle boring out to LS3 dimensions.
Yes it's possible to get the L76 sleeves cut out and LS3 sleeves fitted but it's specialised and expensive.
What you're really chasing is an LS3 short block.
Nobody knows your location so helping you find one near "Somewhere" is impossible.

[C_T_V]

Not porting, it's boring....and no the L76 sleeves wont handle boring out to LS3 dimensions.
Yes it's possible to get the L76 sleeves cut out and LS3 sleeves fitted but it's specialised and expensive.
What you're really chasing is an LS3 short block.
Nobody knows your location so helping you find one near "Somewhere" is impossible.
Paul, I'm far away from USA, Saudi Arabia exactly but if there any way to get LS3 short block in good condition and price it would be fine. I Can ship it from USA by sea or Air fright.
Is it expensive in AU?

[Crazy Paul]

Paul, I'm far away from USA, Saudi Arabia exactly but if there any way to get LS3 short block in good condition and price it would be fine. I Can ship it from USA by sea or Air fright.
Is it expensive in AU?
Just a bare LS3 block (no crank or pistons) is about $500 more expensive in AU than in USA.
Contact Greg at Pace and see what he can do for you
Gregwas@PacePerformance.com

[Crazy Paul]

http://www.ebay.com/itm/GM-6-2L-LS3-Short-Block-Std-Bore-Block-Pistons-Rods-Cranks-Bearings-more-/381078765747?pt=Motors_Car_Truck_Parts_Accessories&hash=item58ba1080b3&vxp=mtr

http://www.ebay.com/itm/New-TMS-LS3-aluminum-short-block-/271122849751?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f202e5fd7&vxp=mtr

[C_T_V]

http://www.ebay.com/itm/GM-6-2L-LS3-Short-Block-Std-Bore-Block-Pistons-Rods-Cranks-Bearings-more-/381078765747?pt=Motors_Car_Truck_Parts_Accessories&hash=item58ba1080b3&vxp=mtr

http://www.ebay.com/itm/New-TMS-LS3-aluminum-short-block-/271122849751?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f202e5fd7&vxp=mtr

Thanks Paul
can help me with GM LS3 short block part number?
first one is good and I will contact the dealer to find out if he can ship it me

[Crazy Paul]

Naah, I only have Part Numbers for bare block (no moving parts) and long block (too many parts).

[C_T_V]

Naah, I only have Part Numbers for bare block (no moving parts) and long block (too many parts).
when I search I found this Number GM 12623967
all other parts I can find it in tonkinonlineparts right?

[Crazy Paul]

Yes 967 is a bare block, no pistons, no crank.
Yes.

[C_T_V]

Yes 967 is a bare block, no pistons, no crank.
Yes.
Thanks Paul for confirmation
I will search about other parts, we can use our stock rods and crank? and just buy new pistons and bearings

[Crazy Paul]

Thanks Paul for confirmation
I will search about other parts, we can use our stock rods and crank? and just buy new pistons and bearings
Not sure on the rods...compare part numbers between L76 and LS3. Length will be the same, but pin arrangement needs checking.
The old L76 crank you have is balanced for 4.00" pistons.
If you put 8 x larger 4.065" pistons onto the L76 crank then it will no longer be balanced.
Sure you could get the whole new mongrel assembly rebalanced.

[C_T_V]

Not sure on the rods...compare part numbers between L76 and LS3. Length will be the same, but pin arrangement needs checking.
The old L76 crank you have is balanced for 4.00" pistons.
If you put 8 x larger 4.065" pistons onto the L76 crank then it will no longer be balanced.
Sure you could get the whole new mongrel assembly rebalanced.
I think we will go with a rotating assembly 402ci or 408ci
4.0 crank
6.125 rods
Flat top pistons
Should we change the OEM Sleeves?
Which kit can we used? Good quality and not very expensive
Lunati,CB...etc

[travis gore]

I think we will go with a rotating assembly 402ci or 408ci
4.0 crank
6.125 rods
Flat top pistons
Should we change the OEM Sleeves?
Which kit can we used? Good quality and not very expensive
Lunati,CB...etc

Mine is a 404. We bought the rotating assembly from Livernois.

[C_T_V]

Mine is a 404. We bought the rotating assembly from Livernois.
Did you change the sleeves? And what about the quality of this kit?

[-Ray-]

Did you change the sleeves? And what about the quality of this kit?

Sleeves were not changed. Cylinders were honed .005" over. New rings were filed to proper gap. You will need a die grinder to relieve the block for the stroker crank. Rods will contact the block if you don't. The quality of the kit was great. Manley forged crank and rods. Ross forged racing pistons. Don't expect much in the way of support from Livernois though. The guy in the parts dept is an asshat.
Personally, I won't buy from Livernois again, and I let them know when I was at the Performance racing industry show last week. That shouldn't stop you though.

[-Ray-]

Did you change the sleeves? And what about the quality of this kit?

Sleeves were not changed. Cylinders were honed .005" over. New rings were filed to proper gap. You will need a die grinder to relieve the block for the stroker crank. Rods will contact the block if you don't. The quality of the kit was great. Manley forged crank and rods. Ross forged racing pistons. Don't expect much in the way of support from Livernois though. The guy in the parts dept is an asshat.
Personally, I won't buy from Livernois again, and I let them know when I was at the Performance racing industry show last week. That shouldn't stop you though.
PS: make sure you get pistons that are relieved for a 58 reluctor.

[travis gore]

Did you change the sleeves? And what about the quality of this kit?

Like Ray said quality was great.

[C_T_V]

Like Ray said quality was great.
After studying the issue we decided to buy LS3 short block ,Because there was no our workshops we can guarantee their work of boring the block and installing the sleeves
but we don't know which crank stroke to go with 4.10 or 4.125 for N/A use