Head bolts. Proper way to torque.
06-25-2007, 05:59 PM
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Head bolts. Proper way to torque. I need to to know the proper way to torque the head bolts on a 98 LS1. I have 500 miles or so and a head gasket went. I originally torqued to 22 lbs, then turned another 90 degrees. My friend told me that I have to then turn the bolts another 90 degrees. I just want to make sure that I get it right as my new bolts and gaskets come in tomorrow.
Also, I had my exhaust rehung and my y pipe hits a lot of bumps on the freeway!
I am going to get it fixed, but could this had contributed to the head gasket problem from the hard impacts on the y pipe transfering the force of the impact to the long tube moving the head? The motor was fine until the car had the exhaust redone, but my buddy said it was just a ticking time bomb anyway.
Also, I had my exhaust rehung and my y pipe hits a lot of bumps on the freeway!
I am going to get it fixed, but could this had contributed to the head gasket problem from the hard impacts on the y pipe transfering the force of the impact to the long tube moving the head? The motor was fine until the car had the exhaust redone, but my buddy said it was just a ticking time bomb anyway. 
06-25-2007, 05:59 PM
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http://www.ls1howto.com/index.php?article=3
Lay the new head gaskets in place. NOTICE how they go on...there is writing inscribed on them pointing to what should be facing front, what should be up, and what is visible. If you get these wrong you will block coolant passages so make sure you do this correctly.
Now lay the new head in place, making sure to get the head correctly on the two dowels that are in the block (dowels are in the bottom bolt holes..furthest back and front most). Go ahead and start threading the M-8 bolts back in by hand. You can reuse the small M-8 bolts if you wish, but you need to apply some locktite to them (GM locktite PN 12345382). If you bought new M-8 bolts they come with locktite pre-applied. Remember where the 2 shorter M-11 bolts went in (top row, furthest back and furthest front) and hand thread those in...then put the 8 longer ones in once again by hand.
Now, grab a socket wrench and lightly turn the bolts until they stop. Now for the very precice part. You need to get your torque wrench out now and fit it with a 3" extension and a 15mm socket.
Using the sequence illustrated above, torque all 10 15mm bolts to 22lb-ft.
Ok, now for a GREAT tip from Scott99Z. Take a felt tip marker and draw a horizontal line on the head of each bolt. This is very important.
Now, using the sequence illustrated above, turn all 10 15mm bolts an additional 90 degrees using a large socket wrench and a lot of muscle. Try to get as close to 90 degreees as possible...you may have to do multiple turns of 30 degrees or 2 turns of 45 degrees. When done all the lines on the bolt heads should be totally vertical.
Next, again using the sequence above, turn bolts 1 through 8 another 90 degrees. This will take an immense amount of effort...if you have a buddy helping both of you should turn the wrench simultanoiusly. These 8 bolts will now all have horizontal lines on them
Using the sequence above, turn bolts 9 and 10 an additional 50 degrees. Again, this will take a lot of effort. 50 degrees should result in a diagonal line on the bolts
Finally, using the sequence above, torque bolts 11 through 15 to 22 lb-ft.
Now lay the new head in place, making sure to get the head correctly on the two dowels that are in the block (dowels are in the bottom bolt holes..furthest back and front most). Go ahead and start threading the M-8 bolts back in by hand. You can reuse the small M-8 bolts if you wish, but you need to apply some locktite to them (GM locktite PN 12345382). If you bought new M-8 bolts they come with locktite pre-applied. Remember where the 2 shorter M-11 bolts went in (top row, furthest back and furthest front) and hand thread those in...then put the 8 longer ones in once again by hand.
Now, grab a socket wrench and lightly turn the bolts until they stop. Now for the very precice part. You need to get your torque wrench out now and fit it with a 3" extension and a 15mm socket.
Using the sequence illustrated above, torque all 10 15mm bolts to 22lb-ft.
Ok, now for a GREAT tip from Scott99Z. Take a felt tip marker and draw a horizontal line on the head of each bolt. This is very important.
Now, using the sequence illustrated above, turn all 10 15mm bolts an additional 90 degrees using a large socket wrench and a lot of muscle. Try to get as close to 90 degreees as possible...you may have to do multiple turns of 30 degrees or 2 turns of 45 degrees. When done all the lines on the bolt heads should be totally vertical.
Next, again using the sequence above, turn bolts 1 through 8 another 90 degrees. This will take an immense amount of effort...if you have a buddy helping both of you should turn the wrench simultanoiusly. These 8 bolts will now all have horizontal lines on them
Using the sequence above, turn bolts 9 and 10 an additional 50 degrees. Again, this will take a lot of effort. 50 degrees should result in a diagonal line on the bolts
Finally, using the sequence above, torque bolts 11 through 15 to 22 lb-ft.
