Arp 425s will hold down over 65psi at 135# torque. 90 psi with orings. The arp 625s will hold 125psi with orings. Don't get fire rings.
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Fire ring or oring or just studs
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well I'm pretty sure I know where that 135lb/ft torque number came from as I have said in the past that I torqued my studs down to 135lbs/ft and I held 65psi (which now they are holding 75psi and holding up to 10* added timing from the quadzilla)
however I didn't said this was a spec everyone should follow, nor did I guarantee that it would hold in any/all conditions. In fact there are no guarantees it will hold at all! so many different factors come in to play with head gaskets and how they can blow it's ridiculous...
I am personally taking a risk by over torquing my head studs by 10lbs/ft (a number I came up with myself to try as an experiment) and running excessive boost pressures and timing on a standard head gasket.
so far it has worked out well for me, but I'm not going to tell everyone it will absolutely hold at those specs, because there is no guarantee it will. It's just a WAG (wild as$ guess) on my part that I decided to try because I'm cheap.
another reason you can't say it will hold up to xx bost pressure is because boost isn't the only factor you have to take into account...
excessive drive pressure will blow a gasket faster than boost pressure will..
"well johnnyspaceship said I could run 65psi with studs at 135# so I ran my hy35 to 65psi and my head gasket blew?! wtf?!"
not trying to beat ya up here guy, just trying to say to choose how you word things carefully. saying numbers like that as if they are fact causes misinformation and confusion and could cost a fellow member problems if they don't know that there is risk involved with following something another member with no qualifications or certifications came up with for their own rig. :thumbsup:
Josh likes crackin the whip on members that do that (including me as I have been guilty of it before) and is very blunt about it. don't take it personally though, he's a good guy and just trying to keep information as accurate as possible so the lines between theory and proven fact are not blurred. (btw proving a theory on one truck does not make the theory a fact. what works for one might not work for another)
however I didn't said this was a spec everyone should follow, nor did I guarantee that it would hold in any/all conditions. In fact there are no guarantees it will hold at all! so many different factors come in to play with head gaskets and how they can blow it's ridiculous...
I am personally taking a risk by over torquing my head studs by 10lbs/ft (a number I came up with myself to try as an experiment) and running excessive boost pressures and timing on a standard head gasket.
so far it has worked out well for me, but I'm not going to tell everyone it will absolutely hold at those specs, because there is no guarantee it will. It's just a WAG (wild as$ guess) on my part that I decided to try because I'm cheap.
another reason you can't say it will hold up to xx bost pressure is because boost isn't the only factor you have to take into account...
excessive drive pressure will blow a gasket faster than boost pressure will..
"well johnnyspaceship said I could run 65psi with studs at 135# so I ran my hy35 to 65psi and my head gasket blew?! wtf?!"
not trying to beat ya up here guy, just trying to say to choose how you word things carefully. saying numbers like that as if they are fact causes misinformation and confusion and could cost a fellow member problems if they don't know that there is risk involved with following something another member with no qualifications or certifications came up with for their own rig. :thumbsup:
Josh likes crackin the whip on members that do that (including me as I have been guilty of it before) and is very blunt about it. don't take it personally though, he's a good guy and just trying to keep information as accurate as possible so the lines between theory and proven fact are not blurred. (btw proving a theory on one truck does not make the theory a fact. what works for one might not work for another)
O god, what have I done this time?Some more great advice....
I've got my drive pressure to about 70 when I'm at 60 at the horn. So that's 1:1.15 or so. Isn't as close to 1:1 as you can get what you want?
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