H11's vs 625 ARP's

those 14mm arp 625's were for a 24v and 3600 for one set and 2400 for 3 sets.. i talked to him about them.. im not real sure why they dont make these but probably has something to do with the block not holding that much more torque..
 
The price premium for the 625+ is due to the nickel-base alloy used... $$$ stuff but performance and durability are much better - they're an investment, good for season after season, build after build, no worries with handling issues, high-temp strength, coolant corrosion, hydrogen embrittlement, etc.

Costs 2X but easily lasts 3X+ in the long run.
 
I use some cheap $100 things that are a bit stronger than stock LOL held 65psi a few times. On a single charger though.

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If you have a really good block and head, the stock bolts over-torqued with stock gasket will hold 85-90 psi boost and 1200-1400 ft lbs at the wheels.
 
zstroken said:
9/16'=0.5625"
14mm=0.5512"

While they are similar, I wouldn't say they are equal.

I would say a good set of 425 ARP in 9/16" will hold a good amount.
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That's what I was thinking. They're only .0055" closer to the bore so I don't see that being a problem.
 
It would be interesting to take a few different materials and play with the torque wrench to see what it took to break the studs. Have some 17-4 centerless ground and then thread rolled to a 13mm thread and then see how much torque it took to twist it off. With a 13mm thread you could ream the holes in the block to size(very easy) and then have 2 taps made. One with a long taper that would follow an of the existing 12mm thread, and a bottom tap for finishing.By going to a 13mm stud you might pick up enough strength from the extra diameter to make up for the lack of material strength. Lots of different materials and heat treat processes available.
 
Snapped an h11 stud off last night at 150 pounds torque. Have done 3 sets of arp 425s at 155 pounds torque. Makes no sense to me and kind of pisses me off.
 
kansasfirstgen said:
Snapped an h11 stud off last night at 150 pounds torque. Have done 3 sets of arp 425s at 155 pounds torque. Makes no sense to me and kind of pisses me off.
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What kind of lube were you using when this happened? and on the 425's?

I've been looking at the h11's very hard lately.
 
Don't mean to high jack the thread but what would a 64/s480 compound setup produce boost wise and what would be the best thing to do run 14mm studs or the 625s
 
running my 425s at 80psi now for the last 17k miles. no problems at all. 3 re torques and did the install a slow 5lbs at a time but absolutely no problems here.
 
Ya that's what i did to ^. very slow I did 100 110 120 130 135 140 145 150 heat cycle 150 heat cycle 150.
 
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nike said:
What kind of lube were you using when this happened? and on the 425's?

I've been looking at the h11's very hard lately.
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ARP ultra and lots of it. Only oil on the coarse end. Every other stud reached torque crisply with no signs of stretch. I am running arp 425s under 80 psi of boost with no problems.
 
I posted my boost number because that's the ultimate tell-tale sign of how much abuse the head bolts or studs are taking.......

I probably should have posted my drive pressure numbers.......


Seriously, there are so many factors associated with why a head gasket blows or stays in-tact that it's almost comical to post boost numbers.


I make more boost than RonA, but he makes double the torque at the same RPM range with higher static timing, whose head fasteners are under more stress?

...probably mine because I make the most boost!
 
I see a lot of folks talking about boost in relation to how likely a gasket is to hold up, but its a combo of a bunch of things including timing, compression and maybe even port work.
Any thoughts on whether a ported head that drops effective boost might help keep a gasket on the head? I dont see how though.
Im putting a hamilton head on this motor and probably the 625 studs as insurance, but honestly dont plan to go over 700hp.. just want a reliable 650.
425's on there now, not sure If I should try a torque to 150 and see, or just go straight to the 625's with 160ftlb or a little more.
 
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