Head Studs A Couple ??????????????
Registered User
Joined: Mar 2005
Posts: 327
From: Tulsa OK
i bought some of those as main studs.. and i had ARP head studs and the brand name on them is Procomp, so far they have been awsome ive beat the hell out of them with 2bolt mains and 500+ hp 6500rpm for several thousand miles so far and from a visual comparison they are absolutly identical too the ARP in every way.. As of now i wouldnt hesitate too use them again
Registered User
Joined: Jun 1999
Posts: 939
From: Lowcountry
Sometimes something comes along and irks you enough to bring you out of lurking.
I think there's a lot of misconceptions and simplifications going on here. A fastener is very simple in general terms and it does a fairly simple job. To do that job well it becomes very complicated.
The macro-geometry is important but just a small change in radii can make big changes in performance. Are your eyes good enough to catch even this? Forming can have big effects on performance, are the threads cut or rolled?
Not all materials are alike, very far from. Just as important as material is process. You can have two identical materials and treating them differently will yield completely different characteristics. Big failures start as atomic size flaws. They look the same? Unless you've got the eyes of an electron scanning microscope and know every bit of the material's history that means absolutely nothing. It's the microscopic characteristics of materials that determine their fatigue performance. Residual stress, grain structure, lattice structure, solute dispersion, load history, etc.
Most alloys do not automatically ensure specific material properties. Just the opposite in fact. Alloying often permits the possibility of certain properties if, and only if, treated absolutely right. Have these had the same expensive and highly controlled treatments as ARP fasteners?
Creating a material with the best properties can be a very expensive and highly controlled process. Just a fraction of a percent of a contaminant can create vastly different good or bad properties. The Chinese seem to have enough difficulty making and using a simple blast furnace. You think they can build and use a superior arc furnace to make a superior material?
A tensile test is a very simple, one dimensional, static type experimental test. That alone doesn't give much information on the performance of a finished product. If these bolts "look" the same and are made of the "same" material why is something as simple as a tensile test resulting in different results?
All of this and much more is very important, especially in a fastener that is cycled completely [hopefully!] in the tension domain.
I don't even know if the fasteners in question are Chinese or not but I'm assuming they are. The Chinese have a well deserved reputation of copying, not designing, products. The result is less than robust components. Much like many of the people here they simply assume if it looks the same, it is the same. No offense but I wouldn't trust fasteners designed by you guys. "Looking" says about as much as smelling the same.
In a head stud/bolt application I wouldn't be as worried about it. I'd rather lose a head gasket or fastener before other things. Unless you could show me all the pertinent information and a very well established record there's no way in hell I'd use them in a rotating assembly.
I used cheapy rocker arm studs to save a few bucks. The fatigue failure resulted in a broken car on the I-90 expressway and the destruction of an expensive valve cover. I use ARP now... it's cheaper in the long run
I think there's a lot of misconceptions and simplifications going on here. A fastener is very simple in general terms and it does a fairly simple job. To do that job well it becomes very complicated.
The macro-geometry is important but just a small change in radii can make big changes in performance. Are your eyes good enough to catch even this? Forming can have big effects on performance, are the threads cut or rolled?
Not all materials are alike, very far from. Just as important as material is process. You can have two identical materials and treating them differently will yield completely different characteristics. Big failures start as atomic size flaws. They look the same? Unless you've got the eyes of an electron scanning microscope and know every bit of the material's history that means absolutely nothing. It's the microscopic characteristics of materials that determine their fatigue performance. Residual stress, grain structure, lattice structure, solute dispersion, load history, etc.
Most alloys do not automatically ensure specific material properties. Just the opposite in fact. Alloying often permits the possibility of certain properties if, and only if, treated absolutely right. Have these had the same expensive and highly controlled treatments as ARP fasteners?
Creating a material with the best properties can be a very expensive and highly controlled process. Just a fraction of a percent of a contaminant can create vastly different good or bad properties. The Chinese seem to have enough difficulty making and using a simple blast furnace. You think they can build and use a superior arc furnace to make a superior material?
A tensile test is a very simple, one dimensional, static type experimental test. That alone doesn't give much information on the performance of a finished product. If these bolts "look" the same and are made of the "same" material why is something as simple as a tensile test resulting in different results?
All of this and much more is very important, especially in a fastener that is cycled completely [hopefully!] in the tension domain.
I don't even know if the fasteners in question are Chinese or not but I'm assuming they are. The Chinese have a well deserved reputation of copying, not designing, products. The result is less than robust components. Much like many of the people here they simply assume if it looks the same, it is the same. No offense but I wouldn't trust fasteners designed by you guys. "Looking" says about as much as smelling the same.
In a head stud/bolt application I wouldn't be as worried about it. I'd rather lose a head gasket or fastener before other things. Unless you could show me all the pertinent information and a very well established record there's no way in hell I'd use them in a rotating assembly.
I used cheapy rocker arm studs to save a few bucks. The fatigue failure resulted in a broken car on the I-90 expressway and the destruction of an expensive valve cover. I use ARP now... it's cheaper in the long run
Registered User
Joined: Feb 2002
Posts: 5,645
From: Bridgewater, MA
Sometimes something comes along and irks you enough to bring you out of lurking.
I think there's a lot of misconceptions and simplifications going on here. A fastener is very simple in general terms and it does a fairly simple job. To do that job well it becomes very complicated.
The macro-geometry is important but just a small change in radii can make big changes in performance. Are your eyes good enough to catch even this? Forming can have big effects on performance, are the threads cut or rolled?
Not all materials are alike, very far from. Just as important as material is process. You can have two identical materials and treating them differently will yield completely different characteristics. Big failures start as atomic size flaws. They look the same? Unless you've got the eyes of an electron scanning microscope and know every bit of the material's history that means absolutely nothing. It's the microscopic characteristics of materials that determine their fatigue performance. Residual stress, grain structure, lattice structure, solute dispersion, load history, etc.
Most alloys do not automatically ensure specific material properties. Just the opposite in fact. Alloying often permits the possibility of certain properties if, and only if, treated absolutely right. Have these had the same expensive and highly controlled treatments as ARP fasteners?
Creating a material with the best properties can be a very expensive and highly controlled process. Just a fraction of a percent of a contaminant can create vastly different good or bad properties. The Chinese seem to have enough difficulty making and using a simple blast furnace. You think they can build and use a superior arc furnace to make a superior material?
A tensile test is a very simple, one dimensional, static type experimental test. That alone doesn't give much information on the performance of a finished product. If these bolts "look" the same and are made of the "same" material why is something as simple as a tensile test resulting in different results?
All of this and much more is very important, especially in a fastener that is cycled completely [hopefully!] in the tension domain.
I don't even know if the fasteners in question are Chinese or not but I'm assuming they are. The Chinese have a well deserved reputation of copying, not designing, products. The result is less than robust components. Much like many of the people here they simply assume if it looks the same, it is the same. No offense but I wouldn't trust fasteners designed by you guys. "Looking" says about as much as smelling the same.
In a head stud/bolt application I wouldn't be as worried about it. I'd rather lose a head gasket or fastener before other things. Unless you could show me all the pertinent information and a very well established record there's no way in hell I'd use them in a rotating assembly.
I used cheapy rocker arm studs to save a few bucks. The fatigue failure resulted in a broken car on the I-90 expressway and the destruction of an expensive valve cover. I use ARP now... it's cheaper in the long run
I think there's a lot of misconceptions and simplifications going on here. A fastener is very simple in general terms and it does a fairly simple job. To do that job well it becomes very complicated.
The macro-geometry is important but just a small change in radii can make big changes in performance. Are your eyes good enough to catch even this? Forming can have big effects on performance, are the threads cut or rolled?
Not all materials are alike, very far from. Just as important as material is process. You can have two identical materials and treating them differently will yield completely different characteristics. Big failures start as atomic size flaws. They look the same? Unless you've got the eyes of an electron scanning microscope and know every bit of the material's history that means absolutely nothing. It's the microscopic characteristics of materials that determine their fatigue performance. Residual stress, grain structure, lattice structure, solute dispersion, load history, etc.
Most alloys do not automatically ensure specific material properties. Just the opposite in fact. Alloying often permits the possibility of certain properties if, and only if, treated absolutely right. Have these had the same expensive and highly controlled treatments as ARP fasteners?
Creating a material with the best properties can be a very expensive and highly controlled process. Just a fraction of a percent of a contaminant can create vastly different good or bad properties. The Chinese seem to have enough difficulty making and using a simple blast furnace. You think they can build and use a superior arc furnace to make a superior material?
A tensile test is a very simple, one dimensional, static type experimental test. That alone doesn't give much information on the performance of a finished product. If these bolts "look" the same and are made of the "same" material why is something as simple as a tensile test resulting in different results?
All of this and much more is very important, especially in a fastener that is cycled completely [hopefully!] in the tension domain.
I don't even know if the fasteners in question are Chinese or not but I'm assuming they are. The Chinese have a well deserved reputation of copying, not designing, products. The result is less than robust components. Much like many of the people here they simply assume if it looks the same, it is the same. No offense but I wouldn't trust fasteners designed by you guys. "Looking" says about as much as smelling the same.
In a head stud/bolt application I wouldn't be as worried about it. I'd rather lose a head gasket or fastener before other things. Unless you could show me all the pertinent information and a very well established record there's no way in hell I'd use them in a rotating assembly.
I used cheapy rocker arm studs to save a few bucks. The fatigue failure resulted in a broken car on the I-90 expressway and the destruction of an expensive valve cover. I use ARP now... it's cheaper in the long run
I figure worst case is a head gasket goes. I wanted to give them a try after losing $100 to a member on ls1tech when he lied about the ARP head studs he sent me. I asked if they were the studs with the allen wrench hole in them and he said yes... what came in the mail was less than half had the allen, some missing washers and some missing nuts. I am already down $100 and didnt want to pay another $150 for new ARP's... hence my gamble. FYI, my bottom end is built with ARP stuff. Tensile strength is key with these studs... that and cylical loading (fatigue). I just got a feeling I dont have much o worry about with these studs.
Registered User
Joined: Nov 2003
Posts: 1,770
From: Mishawaka, IN
Two words: Quality control.
Eagle makes 4340 cranks and so does Callies. Which one do you want?
Just because they're made out of the same material doesn't mean they'll perform equally. The cheaper ones may work fine. The question is whether or not you want to take the risk.
Eagle makes 4340 cranks and so does Callies. Which one do you want?
Just because they're made out of the same material doesn't mean they'll perform equally. The cheaper ones may work fine. The question is whether or not you want to take the risk.
Registered User
Joined: Jun 1999
Posts: 939
From: Lowcountry
I figure worst case is a head gasket goes. I wanted to give them a try after losing $100 to a member on ls1tech when he lied about the ARP head studs he sent me. I asked if they were the studs with the allen wrench hole in them and he said yes... what came in the mail was less than half had the allen, some missing washers and some missing nuts. I am already down $100 and didnt want to pay another $150 for new ARP's... hence my gamble. FYI, my bottom end is built with ARP stuff. Tensile strength is key with these studs... that and cylical loading (fatigue). I just got a feeling I dont have much o worry about with these studs.
As I said, a head stud is probably the better place to "test" a cheaper fastener.
Registered User
Joined: Feb 2002
Posts: 5,645
From: Bridgewater, MA
Understandable. As long as everyone is aware that you can't judge a fastener by its looks. Fasteners really are a gamble so choose wisely. Hopefully everyone is installing cheap fasteners with cheap tools, since they are all the same
As I said, a head stud is probably the better place to "test" a cheaper fastener.
As I said, a head stud is probably the better place to "test" a cheaper fastener.
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