Larger head bolts/studs (LSX/LQ9)
01-08-2008, 06:06 PM
#1
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Larger head bolts/studs (LSX/LQ9) This is my first time in the advanced section so please be kind...
I was reading the thread in the FI section about the aussie LSX that made 1500+hp with a 106mm turbo. It mentioned something about larger head studs being used because of the high boost (30-40lbs it sais) lifting the heads.
So my question is. If I where to use an LQ9 block, which has 4 hed studs per cylinder (significantly cheeper than an LSX, which has 6 head studs per cylinder) and modify it (and the heads) to use larger head studs would I then have similar (or atleast better than regular LQ9) head lifting resistance to an unmodified LSX block? -ie less head studs per cylinder than an LSX but bigger head studs?
PS I hope this makes sence
I was reading the thread in the FI section about the aussie LSX that made 1500+hp with a 106mm turbo. It mentioned something about larger head studs being used because of the high boost (30-40lbs it sais) lifting the heads.
So my question is. If I where to use an LQ9 block, which has 4 hed studs per cylinder (significantly cheeper than an LSX, which has 6 head studs per cylinder) and modify it (and the heads) to use larger head studs would I then have similar (or atleast better than regular LQ9) head lifting resistance to an unmodified LSX block? -ie less head studs per cylinder than an LSX but bigger head studs?
PS I hope this makes sence
01-08-2008, 11:45 PM
#2
IF clamping force of the head studs is the issue then yes, if its the flimsy decks of the stock heads blowing in the wind then no. I have 0 forced induction experiance with LS1's though, I'll let one of those guys chime in and let us know about the root cause of the issue.
01-10-2008, 09:56 AM
#4
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Call up AFR and world and see what they have to say about it. I know AFR has quite a thick deck for boosted applications.
Thicker studs is one of those things that you might be fine without....or the head might lift and blow the motor up. Either way, if you're going boosted, the thicker studs are probably a good thing, if only for peace of mind.
Thicker studs is one of those things that you might be fine without....or the head might lift and blow the motor up. Either way, if you're going boosted, the thicker studs are probably a good thing, if only for peace of mind.
01-10-2008, 10:28 PM
#6
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I was concerned about this aswel. I was hopeing someone who has done this could enlighten me as to a preferred size that is considered a healthy compromise of head stud diameter and block streingth.
Search wasn't overly helpfull
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01-15-2008, 01:45 AM
#11
xLBx on here is running a LS2 and putting over 1000rwhp to the ground. he is using an orgined block and heads with copper headgasket and 9/16 headstuds!
if you want the ultimate then i think w2w have welded metal to the heads to give them another 2 studs per cylinder! think that what they where using on thier race car.
off topic, but lets sya you had a really really thick deck, something stupid like 1.5inch, would that stup all head lifting?? or is it down the the clamping preusre of the studs aswell????
Chris.
if you want the ultimate then i think w2w have welded metal to the heads to give them another 2 studs per cylinder! think that what they where using on thier race car.
off topic, but lets sya you had a really really thick deck, something stupid like 1.5inch, would that stup all head lifting?? or is it down the the clamping preusre of the studs aswell????
Chris.
01-15-2008, 01:29 PM
#13
xLBx on here is running a LS2 and putting over 1000rwhp to the ground. he is using an orgined block and heads with copper headgasket and 9/16 headstuds!
if you want the ultimate then i think w2w have welded metal to the heads to give them another 2 studs per cylinder! think that what they where using on thier race car.
off topic, but lets sya you had a really really thick deck, something stupid like 1.5inch, would that stup all head lifting?? or is it down the the clamping preusre of the studs aswell????
Chris.
if you want the ultimate then i think w2w have welded metal to the heads to give them another 2 studs per cylinder! think that what they where using on thier race car.
off topic, but lets sya you had a really really thick deck, something stupid like 1.5inch, would that stup all head lifting?? or is it down the the clamping preusre of the studs aswell????
Chris.
01-16-2008, 01:47 AM
#16
OMG thats alot of force! so i guess the next question is how thick dose the deck have to be to stop iot from warping/twisting???
by the way read some stuff on the Australian guys running mega boost. one guy said at 40psi he was totaly warping the block and causing all kinds of problems! this was on a iron LS block.
thanks Chris.
01-16-2008, 04:51 PM
#17
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I thought the Aussie guy (orange monaro 4dr right?) was running an LSX block? Or is that a different guy?
Welded metal to the heads to give an extra 2 head studs per cylinder? Was that a cheeper alternative to an LSX block? This might be another posibility.
1 inch head studs? Now we're talking, lol. The goal here is 21psi or so... (that ought to be good for 1200hp to the wheels?). I guess I'll have to talk to an engine builder about how big I can go. I'd really like to avoid buying an LSX block... unless its the tall deck version.
Welded metal to the heads to give an extra 2 head studs per cylinder? Was that a cheeper alternative to an LSX block? This might be another posibility.
1 inch head studs? Now we're talking, lol. The goal here is 21psi or so... (that ought to be good for 1200hp to the wheels?). I guess I'll have to talk to an engine builder about how big I can go. I'd really like to avoid buying an LSX block... unless its the tall deck version.
01-17-2008, 01:49 AM
#18
I thought the Aussie guy (orange monaro 4dr right?) was running an LSX block? Or is that a different guy?
Welded metal to the heads to give an extra 2 head studs per cylinder? Was that a cheeper alternative to an LSX block? This might be another posibility.
1 inch head studs? Now we're talking, lol. The goal here is 21psi or so... (that ought to be good for 1200hp to the wheels?). I guess I'll have to talk to an engine builder about how big I can go. I'd really like to avoid buying an LSX block... unless its the tall deck version.
Welded metal to the heads to give an extra 2 head studs per cylinder? Was that a cheeper alternative to an LSX block? This might be another posibility.
1 inch head studs? Now we're talking, lol. The goal here is 21psi or so... (that ought to be good for 1200hp to the wheels?). I guess I'll have to talk to an engine builder about how big I can go. I'd really like to avoid buying an LSX block... unless its the tall deck version.
W2W did the 'lugs' on the head and block simply cos the LSX or Warhawk wasn't avaliable then. it worked ok for them i think.
so if ally heads lift so baddly, why dosen't someone come out with a iron head?? surrley they would lift even at really high presures?????
Chris.
01-18-2008, 11:33 AM
#19
You can go up to a 9/16 head stud on an iron block.
That being said Very few people have the equipment to do it and it's expensive.
-$500 in machine work on the block
-$200-300 or so on the heads
-$500 special ordered head studs.
At that point you really can't modify a MLS gasket to work properly so you will have to go with Copper. Also the Nuts for the 9/16 studs are so large there may be interference issues with your headers.
That being said Very few people have the equipment to do it and it's expensive.
-$500 in machine work on the block
-$200-300 or so on the heads
-$500 special ordered head studs.
At that point you really can't modify a MLS gasket to work properly so you will have to go with Copper. Also the Nuts for the 9/16 studs are so large there may be interference issues with your headers.