1/2" head studs test
04-25-2006 | 11:33 PM
#21
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From: Northern California
Originally Posted by overZealous1
a touch over the 600rw mark. but i never really pushed it super hard. i first got indications of it on a trip to san diego to meet 350ZNV and the guys at VRT for the performance nissan meet. i was nearly out of water when i got there. having a feeling i was getting light detonation on the lower grade fuel in cali and that started the process. it was fine for awhile driving in oregon alone. but you never know.
04-26-2006 | 06:23 AM
#22
OverZealous, if these are standard steel ARP 1/2 inch studs (based on the price..I imagine they are), they are not rated anywhere near 150ft/lbs. Keep in mind, that although it is possible, even to trq the standard 7/16th ARP studs to 110ft/lbs, you are certainly yielding, or breaking the studs. A studs trq load is determined at 75% yield strength. Standard ARP 1/2 inch studs are rated at 90-100ft/lbs TOPS at 75% yield strength.
I am glad you got the 1/2 inch studs installed, but you should check with ARP on the trq value they recommend. Overtorqing them will damage your studs, and eventually cause the studs to break, with enough heat and cylinder pressure. 100ft/lbs should be MORE than enough to solve the head lift issue.
One last note. The standard ARP studs are uncut (tapper in the center) to account for heat expansion on aluminum heads.
I am glad you got the 1/2 inch studs installed, but you should check with ARP on the trq value they recommend. Overtorqing them will damage your studs, and eventually cause the studs to break, with enough heat and cylinder pressure. 100ft/lbs should be MORE than enough to solve the head lift issue.
One last note. The standard ARP studs are uncut (tapper in the center) to account for heat expansion on aluminum heads.
04-26-2006 | 06:39 AM
#23
sharif, he already explained that he was doing a thread pullout test, which is why he pulled the enormous torque. his test concluded that we can sleep better at night without having to worry quite as much that maybe we might be ruining a block by putting 1/2" headstuds in there just to have them tear out.
04-26-2006 | 06:49 AM
#24
Good Job 
I’ve posted the results of the 1/2" head studs many times before and it's the way to go. We purchased these head studs several months ago, and I know it's not a custom part # - there are several people that make there own tweaks and create there own part numbers - but the ones I have work prefect and are used by Weston Machine on all high boosted blocks. These carbon steel 1/2" studs work best when torqued down to 105-110ftlbs and the L19 can go as high as 140ftlbs.
I'll dig up the part # we're using if anyone wants it.
I’ve posted the results of the 1/2" head studs many times before and it's the way to go. We purchased these head studs several months ago, and I know it's not a custom part # - there are several people that make there own tweaks and create there own part numbers - but the ones I have work prefect and are used by Weston Machine on all high boosted blocks. These carbon steel 1/2" studs work best when torqued down to 105-110ftlbs and the L19 can go as high as 140ftlbs.
I'll dig up the part # we're using if anyone wants it.
04-26-2006 | 07:45 AM
#27
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From: tigard oregon
Originally Posted by Sharif@Forged
OverZealous, if these are standard steel ARP 1/2 inch studs (based on the price..I imagine they are), they are not rated anywhere near 150ft/lbs. Keep in mind, that although it is possible, even to trq the standard 7/16th ARP studs to 110ft/lbs, you are certainly yielding, or breaking the studs. A studs trq load is determined at 75% yield strength. Standard ARP 1/2 inch studs are rated at 90-100ft/lbs TOPS at 75% yield strength.
I am glad you got the 1/2 inch studs installed, but you should check with ARP on the trq value they recommend. Overtorqing them will damage your studs, and eventually cause the studs to break, with enough heat and cylinder pressure. 100ft/lbs should be MORE than enough to solve the head lift issue.
One last note. The standard ARP studs are uncut (tapper in the center) to account for heat expansion on aluminum heads.
I am glad you got the 1/2 inch studs installed, but you should check with ARP on the trq value they recommend. Overtorqing them will damage your studs, and eventually cause the studs to break, with enough heat and cylinder pressure. 100ft/lbs should be MORE than enough to solve the head lift issue.
One last note. The standard ARP studs are uncut (tapper in the center) to account for heat expansion on aluminum heads.
ya the taper is for head expansion, but think it is abit much more clearance than is actually needed. you will need to drill the heads anyways with this set up, so you can custom taylor the hole to account for the larger dia. centers.
04-26-2006 | 08:28 AM
#28
Good work
Good work on this Overzealous. For those of us that already have built blocks with 7/16 studs, what options do we have that don't require our engines to be pulled out and machined for the larger studs (cuz this likely costs some bucks). I know my arp studs were torqued down to 77lbs. What is the thoughts on running 500 rwhp everyday and 600 rwhp on a second map with them torqued to 77lbs with a sleeved motor, cometic head gaskets, 3 inch exhaust and wg dumps? I'll also be using an electric water pump with thermostatic controller in addition to the stock water pump to keep the engine nice an cool. Thanks in advance.
04-27-2006 | 04:05 PM
#30
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From: tigard oregon
sorry so long to get back with an update. i just went on a marathon 20 hours working on my car with 4 hours sleep, lol. swapped in some new head gaskets to try and make a cruise this weekend, will see if it holds.
ok, now the good news. READ ALL OF THIS, VERY IMPORTANT!!
a week or 2 ago i put some coolant/block sealer in my motor. the stuff leaves a trail to the leak and can leave markings to make is easier to find a leak. i found on my head gaskets that only the areas between the bores is leaking. you might not know it now, but that is the best news possible!!!!
the black specs people are finding in their overflow tanks is from a coating on the stock head gaskets, around the bores. the only area i was missing this coating was inbetween the bores. so that is the only place combustion is trying to escape. so, in conclusion, i am starting to not blame the issue as much on head studs stretching, but that the head casting is not strong enough between the bores. my head studs had the same torque on all of them as when i put it in, so retorquing is not the issue either.
now if the leaks had been all around the cylinder, it would be a different story. that would make it so there is not much that can be done at all. this is a fairily targeted fix now that the part flexing has been pinpointed. there was a little indication of the bores moving around also though. seemed to be more towards the outsides of the block though.
here is the best news. i have come up with a very easy, very cheap, and very solid solution to this issue. this will be available in a kit within a couple days from me. a full explanation of the fix will happen at that point.
the combination of the larger head studs and this fix has no doubts in my mind the hp levels will be raised quite a bit. the head studs will definately require removing the motor for machining, but this other fix can be done........................................................ ................IN THE CAR!!!! so even previously built motors or even stock blocks can accept this. will try to get all the parts rounded up tomorrow, and make this available asap!!
scott
ok, now the good news. READ ALL OF THIS, VERY IMPORTANT!!
a week or 2 ago i put some coolant/block sealer in my motor. the stuff leaves a trail to the leak and can leave markings to make is easier to find a leak. i found on my head gaskets that only the areas between the bores is leaking. you might not know it now, but that is the best news possible!!!!
the black specs people are finding in their overflow tanks is from a coating on the stock head gaskets, around the bores. the only area i was missing this coating was inbetween the bores. so that is the only place combustion is trying to escape. so, in conclusion, i am starting to not blame the issue as much on head studs stretching, but that the head casting is not strong enough between the bores. my head studs had the same torque on all of them as when i put it in, so retorquing is not the issue either.
now if the leaks had been all around the cylinder, it would be a different story. that would make it so there is not much that can be done at all. this is a fairily targeted fix now that the part flexing has been pinpointed. there was a little indication of the bores moving around also though. seemed to be more towards the outsides of the block though.
here is the best news. i have come up with a very easy, very cheap, and very solid solution to this issue. this will be available in a kit within a couple days from me. a full explanation of the fix will happen at that point.
the combination of the larger head studs and this fix has no doubts in my mind the hp levels will be raised quite a bit. the head studs will definately require removing the motor for machining, but this other fix can be done........................................................ ................IN THE CAR!!!! so even previously built motors or even stock blocks can accept this. will try to get all the parts rounded up tomorrow, and make this available asap!!
scott
04-27-2006 | 04:13 PM
#32
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From: CALI
Originally Posted by overZealous1
sorry so long to get back with an update. i just went on a marathon 20 hours working on my car with 4 hours sleep, lol. swapped in some new head gaskets to try and make a cruise this weekend, will see if it holds.
ok, now the good news. READ ALL OF THIS, VERY IMPORTANT!!
a week or 2 ago i put some coolant/block sealer in my motor. the stuff leaves a trail to the leak and can leave markings to make is easier to find a leak. i found on my head gaskets that only the areas between the bores is leaking. you might not know it now, but that is the best news possible!!!!
the black specs people are finding in their overflow tanks is from a coating on the stock head gaskets, around the bores. the only area i was missing this coating was inbetween the bores. so that is the only place combustion is trying to escape. so, in conclusion, i am starting to not blame the issue as much on head studs stretching, but that the head casting is not strong enough between the bores. my head studs had the same torque on all of them as when i put it in, so retorquing is not the issue either.
now if the leaks had been all around the cylinder, it would be a different story. that would make it so there is not much that can be done at all. this is a fairily targeted fix now that the part flexing has been pinpointed. there was a little indication of the bores moving around also though. seemed to be more towards the outsides of the block though.
here is the best news. i have come up with a very easy, very cheap, and very solid solution to this issue. this will be available in a kit within a couple days from me. a full explanation of the fix will happen at that point.
the combination of the larger head studs and this fix has no doubts in my mind the hp levels will be raised quite a bit. the head studs will definately require removing the motor for machining, but this other fix can be done........................................................ ................IN THE CAR!!!! so even previously built motors or even stock blocks can accept this. will try to get all the parts rounded up tomorrow, and make this available asap!!
scott
ok, now the good news. READ ALL OF THIS, VERY IMPORTANT!!
a week or 2 ago i put some coolant/block sealer in my motor. the stuff leaves a trail to the leak and can leave markings to make is easier to find a leak. i found on my head gaskets that only the areas between the bores is leaking. you might not know it now, but that is the best news possible!!!!
the black specs people are finding in their overflow tanks is from a coating on the stock head gaskets, around the bores. the only area i was missing this coating was inbetween the bores. so that is the only place combustion is trying to escape. so, in conclusion, i am starting to not blame the issue as much on head studs stretching, but that the head casting is not strong enough between the bores. my head studs had the same torque on all of them as when i put it in, so retorquing is not the issue either.
now if the leaks had been all around the cylinder, it would be a different story. that would make it so there is not much that can be done at all. this is a fairily targeted fix now that the part flexing has been pinpointed. there was a little indication of the bores moving around also though. seemed to be more towards the outsides of the block though.
here is the best news. i have come up with a very easy, very cheap, and very solid solution to this issue. this will be available in a kit within a couple days from me. a full explanation of the fix will happen at that point.
the combination of the larger head studs and this fix has no doubts in my mind the hp levels will be raised quite a bit. the head studs will definately require removing the motor for machining, but this other fix can be done........................................................ ................IN THE CAR!!!! so even previously built motors or even stock blocks can accept this. will try to get all the parts rounded up tomorrow, and make this available asap!!
scott
04-27-2006 | 04:25 PM
#34
Originally Posted by overZealous1
the black specs people are finding in their overflow tanks is from a coating on the stock head gaskets, around the bores. the only area i was missing this coating was inbetween the bores. so that is the only place combustion is trying to escape. so, in conclusion, i am starting to not blame the issue as much on head studs stretching, but that the head casting is not strong enough between the bores. my head studs had the same torque on all of them as when i put it in, so retorquing is not the issue either.
now if the leaks had been all around the cylinder, it would be a different story. that would make it so there is not much that can be done at all.
now if the leaks had been all around the cylinder, it would be a different story. that would make it so there is not much that can be done at all.
upon pulling apart my motor, the area of failure was on both sides of cylinder #3..not in between the cylinders, but on the exhaust and intake side (you could see coolant that had dried and adhered to both sided of the external surface of the block)... the gasket material was also a bit disrupted, but the spaces between the cylinders was untouched
to add, my head studs were also torqued down just fine, the issue is not one of loosening, but of stretching a few thousandths, this will not make the nut any looser necessarily. The oversized studs is still an excellent idea (believe me, several other big players on this forum have been doing a good amount of research in this department as well
)keep up the research, the more we can reveal to each other, the better motors we can build...but sorry to say, this may not be the ULTIMATE solution (your secret)--but the headstuds are going to play a MUCH larger role in the equation, IMHO
Last edited by 350zDCalb; 04-27-2006 at 04:30 PM.
04-27-2006 | 04:50 PM
#35
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From: tigard oregon
both sides of cylinder #3 is what i meant by between the cylinders. i'm talking about the smaller gap between the cylinders, which would be both sides of #3, and #4. ya not calling the ultimate fix, but it will bring the level higher than it is now.
04-27-2006 | 04:51 PM
#36
Originally Posted by 350zDCalb
good job on the research...but I have some very different evidence to reveal. I just recently pulled my forged motor apart as well (had overheating problems as well, suspected cylinder head lift issues)
upon pulling apart my motor, the area of failure was on both sides of cylinder #3..not in between the cylinders, but on the exhaust and intake side (you could see coolant that had dried and adhered to both sided of the external surface of the block)... the gasket material was also a bit disrupted, but the spaces between the cylinders was untouched
to add, my head studs were also torqued down just fine, the issue is not one of loosening, but of stretching a few thousandths, this will not make the nut any looser necessarily. The oversized studs is still an excellent idea (believe me, several other big players on this forum have been doing a good amount of research in this department as well )
keep up the research, the more we can reveal to each other, the better motors we can build...but sorry to say, this may not be the ULTIMATE solution (your secret)--but the headstuds are going to play a MUCH larger role in the equation, IMHO
upon pulling apart my motor, the area of failure was on both sides of cylinder #3..not in between the cylinders, but on the exhaust and intake side (you could see coolant that had dried and adhered to both sided of the external surface of the block)... the gasket material was also a bit disrupted, but the spaces between the cylinders was untouched
to add, my head studs were also torqued down just fine, the issue is not one of loosening, but of stretching a few thousandths, this will not make the nut any looser necessarily. The oversized studs is still an excellent idea (believe me, several other big players on this forum have been doing a good amount of research in this department as well
)keep up the research, the more we can reveal to each other, the better motors we can build...but sorry to say, this may not be the ULTIMATE solution (your secret)--but the headstuds are going to play a MUCH larger role in the equation, IMHO
04-27-2006 | 04:53 PM
#37
Originally Posted by overZealous1
both sides of cylinder #3 is what i meant by between the cylinders. i'm talking about the smaller gap between the cylinders, which would be both sides of #3, and #4. ya not calling the ultimate fix, but it will bring the level higher than it is now.
hmmm, i'm talking about the areas of the cylinder that are closest to the exhaust side and the intake side of the heads...is this where you saw the problem as well?
04-27-2006 | 05:06 PM
#38
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From: tigard oregon
Originally Posted by 350zDCalb
hmmm, i'm talking about the areas of the cylinder that are closest to the exhaust side and the intake side of the heads...is this where you saw the problem as well?
the common thing in both situations is the middle cylinder. i was afraid of this. the center head studs are pulling double duty for the center cylinder and one outer cylinder. they are hitting more stress cycles atleast than the outside head studs. larger head studs will definately help this design afliction.
still my fix and the larger head studs will yield alot higher than we are currently at with reliable high hp street cars.
04-27-2006 | 05:25 PM
#40
Originally Posted by Yancy
I know my arp studs were torqued down to 77lbs. What is the thoughts on running 500 rwhp everyday and 600 rwhp on a second map with them torqued to 77lbs with a sleeved motor, cometic head gaskets, 3 inch exhaust and wg dumps? I'll also be using an electric water pump with thermostatic controller in addition to the stock water pump to keep the engine nice an cool. Thanks in advance.
(2) On another note, If no one has witnessed the head studs fail or stretch, wouldn't that necessarily mean that the head studs are doing their job? From overzealous' latest post, it seems as if non-sleeved blocks may have slight cylinder distortion under high boost which may be breaking the HG seal between the block and heads?
(3) As a hypothetical - say 6 months down the road I decide that I want to change out the head studs to something different either because (a) peace of mind, or (b) need of additional clamping force for the heads. Since I already have a built engine using the standard arp head studs torqued to 77 lbs, couldn't I just go with a different 7/16 head stud that can be torqued down better? (Just trying to avoid the down time in the summer and also the additional labor expense to pull the engine to have the block machined for the 1/2 studs. I would think most people that already have a built engine would think similarly.)