LY6 Head bolt torque and sequence
06-30-2017, 05:19 PM
#1
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LY6 Head bolt torque and sequence I have a 2008 Gen IV LY6 out of a GMC Sierra 2500HD. I am replacing the lifters this weekend as well as installing new Lunati double Valve springs, seats, retainers,locks,pushrods, and a comp cams trunion kit. Does anyone on here know what the proper head bolt torque and tightening sequence is?
The LY6 is a LQ4 block with L92 heads.
The LQ4 is a cast iron block otherwise identical to a LS6.
Thanks for any help you can offer.
The LY6 is a LQ4 block with L92 heads.
The LQ4 is a cast iron block otherwise identical to a LS6.
Thanks for any help you can offer.
06-30-2017, 09:52 PM
#2
Are you using new OEM bolts, or ARP bolts. The OEM bolts use a different method of torquing the bolts using an angle gauge compared to the ARP bolts.
The Iron Block 6.0 LQ4 is not identical to the Aluminum 5.7 LS6 engine. Different style heads (Cathedral vs Rectangular), Different Bores, different block material.
The Torque Specs are listed for an Aluminum Block and may be the same for an Iron Block using the OEM TTY Bolts.
The Iron Block 6.0 LQ4 is not identical to the Aluminum 5.7 LS6 engine. Different style heads (Cathedral vs Rectangular), Different Bores, different block material.
The Torque Specs are listed for an Aluminum Block and may be the same for an Iron Block using the OEM TTY Bolts.
Last edited by 07NBSChevy; 06-30-2017 at 10:56 PM.
06-30-2017, 11:24 PM
#3
Tq specs are the same. Being an 08, it will be the 2nd design (all bolts same length). DO NOT reuse the stock head bolts. $26 per side at any parts store. I also highly suggest new intake gasket too. The truck gaskets don't like to reseal that well when old.
Another good idea is to pull the hex plugs in the block to drain all the coolant from the block so when you pull the heads. That way you won't get any coolant in the cylinders or bolt holes. If you don't, be sure to blow out the bolts holes thoroughly.
Another good idea is to pull the hex plugs in the block to drain all the coolant from the block so when you pull the heads. That way you won't get any coolant in the cylinders or bolt holes. If you don't, be sure to blow out the bolts holes thoroughly.
07-01-2017, 07:17 AM
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Tq specs are the same. Being an 08, it will be the 2nd design (all bolts same length). DO NOT reuse the stock head bolts. $26 per side at any parts store. I also highly suggest new intake gasket too. The truck gaskets don't like to reseal that well when old.
Another good idea is to pull the hex plugs in the block to drain all the coolant from the block so when you pull the heads. That way you won't get any coolant in the cylinders or bolt holes. If you don't, be sure to blow out the bolts holes thoroughly.
Another good idea is to pull the hex plugs in the block to drain all the coolant from the block so when you pull the heads. That way you won't get any coolant in the cylinders or bolt holes. If you don't, be sure to blow out the bolts holes thoroughly.
07-01-2017, 09:07 AM
#5
IIRC, the OEM bolts should have sealant all ready on them.
07-09-2017, 12:04 PM
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The LY6 is a 6 liter cast Iron block engine, this block does not have the 0.006 heat stretch characteristic of the cast aluminum block 70 ft lbs. cylinder head torque is perfect even for boost regardless of bolts or studs.
The M8 bolts as well as all cylinder head bolts are going in to blind holes no sealer needed, what is needed is ARP ultra torque fastener lubricant to obtain proper torque reading.
Another thing needed and very important is to blow every bolt hole clean of coolant as liquids don't compress and will crack the block.
The M8 bolts as well as all cylinder head bolts are going in to blind holes no sealer needed, what is needed is ARP ultra torque fastener lubricant to obtain proper torque reading.
Another thing needed and very important is to blow every bolt hole clean of coolant as liquids don't compress and will crack the block.
Last edited by CAMSTER; 07-09-2017 at 12:20 PM.
