Limit of standard arp headstuds
10-23-2009, 12:59 PM
#41
EDIT, I JUST REALIZED THAT I READ THE QUESTION WRONG. (I HAD "HR" IN MY HEAD). DON'T USE THE TORQUE PROCEEDURE IN THE PDF I POSTED. THAT IS ONLY FOR THE HR HEAD BOLTS.
ARP head bolts should be torqued in stages.
Last edited by ttg35fort; 10-24-2009 at 06:15 AM.
10-23-2009, 01:03 PM
#42
It's not just the max torque you need to be concerned with. They need to be torqued according to a very specific procedure.
The pdf at the following link shows the torqing sequence at the bottom of page 2:
http://www.jimwolftechnology.com/wol...HEAD_BOLTS.pdf
The pdf at the following link shows the torqing sequence at the bottom of page 2:
http://www.jimwolftechnology.com/wol...HEAD_BOLTS.pdf
i read it.
so is it 72 or 77 ft-lb of torque for arp L17?
10-23-2009, 02:18 PM
#43
EDIT:
From Import Parts Pro website (comparing the difference between the L19's and the standard ARP studs):
"..standard ARP studs can be torqued down to 65-70ft/lbs.."
ARP lists the torque spec's for various materials in the table on page 24 of their catalog: http://video.arp-bolts.com/catalog/ARPCatalog.pdf
The standard ARP studs are P/N 202-4701, and made with 8740 chrome moly. The have a tensile strength of 180,000 psi. The table does not list metric sizes, but I beleive that our head studs are 10 mm, which is between 3/8" and 7/16", but closer to 3/8". If you interpolate the numbers from the catalog, it generally corresponds to the torque listed by IPP.
Do not follow the link I previously posted, that was for the HR head bolts, not ARP head bolts (I must have been spacing out). People usually torque them in stages, e.g., 10 ft-lb stages. Here is some guidence from ARP:
1. The friction factor changes from one application to the next.
That is, the friction is at its highest value when the fastener is first
tightened. Each additional time the fastener is torqued and loosened,
this value gets smaller. Eventually the friction levels out and becomes
constant for all following repetitions. Therefore, new fasteners should
be tightened and loosened through several cycles before applying
final torque. The number of times depends on the lubricant. For
all situations where ARP lubricants are used, five cycles are required
before final torquing.
2. The lubricant used is the main factor in determining friction,
and therefore, the torque for a particular installation. Motor oil is a
commonly used lubricant because of it’s ready availability. If less friction
is desired in order to install the fasteners with less torque, special
low friction lubricants are available. With special lubes, the required
torque can be reduced as much as 20 to 30 percent. It is important
to keep in mind that the reverse is also true. If the torque value has
been specified for a particular fastener on the basis of low friction
lube, installing the fastener with motor oil will result in insufficient
preload; the torque has to be increased to compensate for the extra
friction caused by the motor oil.
3. Surface finish is also important. For example, black oxide
behaves differently than a polished fastener. It is therefore important
to observe the torque recommendations supplied with each fastener.
NOTE: It is possible for even the most expensive of torque
wrenches to lose accuracy. We have seen fluctuations of as much as
ten (10) foot pounds of torque from wrench to wrench. Please have
your torque wrench checked periodically for accuracy.
From Import Parts Pro website (comparing the difference between the L19's and the standard ARP studs):
"..standard ARP studs can be torqued down to 65-70ft/lbs.."
ARP lists the torque spec's for various materials in the table on page 24 of their catalog: http://video.arp-bolts.com/catalog/ARPCatalog.pdf
The standard ARP studs are P/N 202-4701, and made with 8740 chrome moly. The have a tensile strength of 180,000 psi. The table does not list metric sizes, but I beleive that our head studs are 10 mm, which is between 3/8" and 7/16", but closer to 3/8". If you interpolate the numbers from the catalog, it generally corresponds to the torque listed by IPP.
Do not follow the link I previously posted, that was for the HR head bolts, not ARP head bolts (I must have been spacing out). People usually torque them in stages, e.g., 10 ft-lb stages. Here is some guidence from ARP:
1. The friction factor changes from one application to the next.
That is, the friction is at its highest value when the fastener is first
tightened. Each additional time the fastener is torqued and loosened,
this value gets smaller. Eventually the friction levels out and becomes
constant for all following repetitions. Therefore, new fasteners should
be tightened and loosened through several cycles before applying
final torque. The number of times depends on the lubricant. For
all situations where ARP lubricants are used, five cycles are required
before final torquing.
2. The lubricant used is the main factor in determining friction,
and therefore, the torque for a particular installation. Motor oil is a
commonly used lubricant because of it’s ready availability. If less friction
is desired in order to install the fasteners with less torque, special
low friction lubricants are available. With special lubes, the required
torque can be reduced as much as 20 to 30 percent. It is important
to keep in mind that the reverse is also true. If the torque value has
been specified for a particular fastener on the basis of low friction
lube, installing the fastener with motor oil will result in insufficient
preload; the torque has to be increased to compensate for the extra
friction caused by the motor oil.
3. Surface finish is also important. For example, black oxide
behaves differently than a polished fastener. It is therefore important
to observe the torque recommendations supplied with each fastener.
NOTE: It is possible for even the most expensive of torque
wrenches to lose accuracy. We have seen fluctuations of as much as
ten (10) foot pounds of torque from wrench to wrench. Please have
your torque wrench checked periodically for accuracy.
Last edited by ttg35fort; 10-24-2009 at 07:14 AM.
11-29-2009, 04:11 PM
#48
I haz da turbos
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Wow. Just shows how out of the loop i am. I still believe in the L19's and HKS headgaskets.
Do the HR headgaskets and headstuds really perform that well?
Do the HR headgaskets and headstuds really perform that well?
11-29-2009, 05:06 PM
#49
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They seem to be good ,up to around 550 hp don't know very well, and i'm talking about HR head studs, head gaskets hold more than that, that's what I have been reading here. me ,i'm going to give them a
, don't plan to go beyong 510 hp , just finish to brake in new cluth , hold up to 500 ft-lb only
, so i'm not changing that clutch again, not even talking about alot of other things that needs to be change.
11-29-2009, 06:12 PM
#51
I haz da turbos
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They seem to be good ,up to around 550 hp don't know very well, and i'm talking about HR head studs, head gaskets hold more than that, that's what I have been reading here. me ,i'm going to give them a , don't plan to go beyong 510 hp , just finish to brake in new cluth , hold up to 500 ft-lb only, so i'm not changing that clutch again, not even talking about alot of other things that needs to be change.
, don't plan to go beyong 510 hp , just finish to brake in new cluth , hold up to 500 ft-lb only, so i'm not changing that clutch again, not even talking about alot of other things that needs to be change.
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