6.0 Block Questions
03-14-2006, 12:05 PM
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6.0 Block Questions I was wondering if any of you guys knew what the differences are between the 6.0L HO escalade block and the 6.0L block from the 2500. Which would be better to use for replacing/upgrading a LS1.
Thanks
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03-14-2006, 12:44 PM
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There is no difference in any of the 6.0 L blocks manufactured in a given time period (LQ4 or LQ9). Also, there is no difference in the head design depending on the time of manufacture. Here's what I mean:
All LQ4/LQ9 blocks manufactured from 1999 through the first part of 2003 are the same. Then mid-year in 2003 until present, the cam journal diameters changed (this is true of all Gen III blocks I believe). Probably some other small changes were made along the way, but nothing major. The same cams will work in all of these engines (standard LS type cam with rear reluctor) because the inside diameter of all cam bearings is the same.
Two head castings have been used for the 6.0 L blocks. In 1999 and 2000, a round exhaust port LS1 look alike head was used, but it was a cast iron head rather than aluminum. Beginning in 2001, the year of the LQ9 BTW), the 6.0 L engines went to an aluminum version of the 243 LS6 head with 72 cc chambers. This head is still in use today and has the casting number 317. The difference in compression ratio between the LQ4 (9.4:1) and the LQ9 (10.3:1 I think) is due to piston crown design. Note the LQ9 has different rods and the crank is different because of the change in bobweight requirement due to the different reciprocating mass of the piston/rod assemblies.
Babcock Publications Engine Builder Magazine has a lot of good information on these Gen III engines. Here is one of the articles http://www.babcox.com/editorial/ar/eb040538.htm. Learn how to use the search engine on that site. It's a wealth of information on standard engines and rebuilding techniques.
Steve
All LQ4/LQ9 blocks manufactured from 1999 through the first part of 2003 are the same. Then mid-year in 2003 until present, the cam journal diameters changed (this is true of all Gen III blocks I believe). Probably some other small changes were made along the way, but nothing major. The same cams will work in all of these engines (standard LS type cam with rear reluctor) because the inside diameter of all cam bearings is the same.
Two head castings have been used for the 6.0 L blocks. In 1999 and 2000, a round exhaust port LS1 look alike head was used, but it was a cast iron head rather than aluminum. Beginning in 2001, the year of the LQ9 BTW), the 6.0 L engines went to an aluminum version of the 243 LS6 head with 72 cc chambers. This head is still in use today and has the casting number 317. The difference in compression ratio between the LQ4 (9.4:1) and the LQ9 (10.3:1 I think) is due to piston crown design. Note the LQ9 has different rods and the crank is different because of the change in bobweight requirement due to the different reciprocating mass of the piston/rod assemblies.
Babcock Publications Engine Builder Magazine has a lot of good information on these Gen III engines. Here is one of the articles http://www.babcox.com/editorial/ar/eb040538.htm. Learn how to use the search engine on that site. It's a wealth of information on standard engines and rebuilding techniques.
Steve
Last edited by Steve Bryant; 03-21-2006 at 07:17 PM.
08-04-2009, 06:08 PM
#3
Thread Revived... There is no difference in any of the 6.0 L blocks manufactured in a given time period (LQ4 or LQ9). Also, there is no difference in the head design depending on the time of manufacture. Here's what I mean:
All LQ4/LQ9 blocks manufactured from 1999 through the first part of 2003 are the same. Then mid-year in 2003 until present, the cam journal diameters changed (this is true of all Gen III blocks I believe). Probably some other small changes were made along the way, but nothing major. The same cams will work in all of these engines (standard LS type cam with rear reluctor) because the inside diameter of all cam bearings is the same.
Two head castings have been used for the 6.0 L blocks. In 1999 and 2000, a round exhaust port LS1 look alike head was used, but it was a cast iron head rather than aluminum. Beginning in 2001, the year of the LQ9 BTW), the 6.0 L engines went to an aluminum version of the 243 LS6 head with 72 cc chambers. This head is still in use today and has the casting number 317. The difference in compression ratio between the LQ4 (9.4:1) and the LQ9 (10.3:1 I think) is due to piston crown design. Note the LQ9 has different rods and the crank is different because of the change in bobweight requirement due to the different reciprocating mass of the piston/rod assemblies.
Babcock Publications Engine Builder Magazine has a lot of good information on these Gen III engines. Here is one of the articles http://www.babcox.com/editorial/ar/eb040538.htm. Learn how to use the search engine on that site. It's a wealth of information on standard engines and rebuilding techniques.
Steve
All LQ4/LQ9 blocks manufactured from 1999 through the first part of 2003 are the same. Then mid-year in 2003 until present, the cam journal diameters changed (this is true of all Gen III blocks I believe). Probably some other small changes were made along the way, but nothing major. The same cams will work in all of these engines (standard LS type cam with rear reluctor) because the inside diameter of all cam bearings is the same.
Two head castings have been used for the 6.0 L blocks. In 1999 and 2000, a round exhaust port LS1 look alike head was used, but it was a cast iron head rather than aluminum. Beginning in 2001, the year of the LQ9 BTW), the 6.0 L engines went to an aluminum version of the 243 LS6 head with 72 cc chambers. This head is still in use today and has the casting number 317. The difference in compression ratio between the LQ4 (9.4:1) and the LQ9 (10.3:1 I think) is due to piston crown design. Note the LQ9 has different rods and the crank is different because of the change in bobweight requirement due to the different reciprocating mass of the piston/rod assemblies.
Babcock Publications Engine Builder Magazine has a lot of good information on these Gen III engines. Here is one of the articles http://www.babcox.com/editorial/ar/eb040538.htm. Learn how to use the search engine on that site. It's a wealth of information on standard engines and rebuilding techniques.
Steve
I have to swap oil pans anyway to get it into a Fbody car. What should I look for, as far as crank and rods go, to determine which block I have? Heads will not be coming off.
