Advantages of head studs
Advantages of head studs What are the advantage of head studs? I can see that if the motor is taken apart often, this would move the wear from the block threads to the stud threads, but was wondering if there were other advantages?
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Don't do it they are a PITA! Take it from me just do ARP head bolts. Way easier to take it apart again if necessary and they are reusable as many times as needed. I also used Cometic gaskets which I reused several times with no issues 
Chris
Chris
I just pulled my heads off with the head studs, let me tell yah after doing almost 10 h/c swaps and removing stock bolts, this was a piece of cake. It took me almost an hour less taking the heads off then it would have with the stock bolts, i think its from the stuff they use on the bolts(loctite i guess) that makes it take soo long to get them out.
Originally Posted by 98_1LE
Why (or how) do they provide superior clamping force?
Also, in an aluminum block with aluminum threads, the chances of galling a thread are high, the more times you R&R heads. Rule of thumb is no more than 4 times, so I've heard ...
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From: Nottingham, Notts, England, UK
Originally Posted by 98_1LE
Why (or how) do they provide superior clamping force?
I read somewhere that engineers use studs and accountants choose bolts.
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From: Lake Zurich, IL
when I had my motor built up I just went w/ARP Head bolts... I thought about studding but I'm not going to be pulling my heads (hopefully) often enough to really need them... plus I've heard you can't get the heads off (or at least passenger side) w/the motor in the car w/studs? Is this true?
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I put head studs on my 99'....I took the heads off so MTI could polish them up, put on dual springs, and 2.05/1.60 valves.....took me at least an hour less to pull my heads....I love'em.
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both heads will come off w/ the motor in the car w/ head studs. stop spreading that rumor. i've done it myself. the friction is not being applied to the aluminum threads, just a pulling force. its the friction of getting tight and the pulling that will cause the threads to gall.
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Originally Posted by mitchntx
The stock bolts are torque to yeild. The studs don't stretch.
...I would bet the ARP studs are made from exactly the same material as the bolts.The only benefit I can see is for multiple head swaps. You can lock the studs into the aluminum block with Loctite (much better to have a bonded threaded assembly). Then when you torque/loosen/retorque ...all of this is done between the stud and nut which are both high tensile steel.
...probably also gives a better torque/tension relationship which will result in more consistant clamp loads across the head.
Ps. I am a Loctite Engineer so nuts and bolts are my bread and butter!
Thanks everyone. I asked my father as well, who is also an engineer, and he agrees that they will not "clamp" any better, or resist stretching unless they are a larger diameter material. Still, to save the wear on the block I think I will order a set.
Why studs offer more clamping force as opposed to bolts:
Studs also provide more accurate and consistent torque loading. Here’s why. When you use bolts to secure the head, the fastener is actually being “twisted” while it’s being torqued to the proper reading. Accordingly, the bolt is reacting to two different forces simultaneously. A stud should be installed in a “relaxed” mode—never crank it in tightly using a jammed nut.
If everything is right, the stud should be installed finger tight. Then, when applying torque to the nut, the stud will stretch only on the vertical axis. Remember, an undercut shorter stud will have a rate similar to a longer, standard shank stud. This provides a more even clamping force on the head. Because the head gasket will compress upon initial torquing, make sure studs and bolts are re-torqued after the engine has been run
If everything is right, the stud should be installed finger tight. Then, when applying torque to the nut, the stud will stretch only on the vertical axis. Remember, an undercut shorter stud will have a rate similar to a longer, standard shank stud. This provides a more even clamping force on the head. Because the head gasket will compress upon initial torquing, make sure studs and bolts are re-torqued after the engine has been run
ive seen some serious small blocks built with arp head bolts. id say they arent worth the money if your not rebuilding the thing all the time or looking to make maximum maximum power. arp head bolts and bolts in general are extrememly strong. im just going with bolts myself. ive also heard you cant take the heads off with studs if the motors in the car. i was tol dthat from my man at ramchargers. ive never tried it though, but it definetely seems like it would be a tight fit...
Short Laymans version: A bolt with be both "stretched" and "twisted" while torqued. A stud will only be "stretched".
This twisting force has to be added into the total force applied to the fastener.
I use red loctite on head studs and install them finger tight. Smokey Yunick and Carrol Smith do (did) as well.
This twisting force has to be added into the total force applied to the fastener.
I use red loctite on head studs and install them finger tight. Smokey Yunick and Carrol Smith do (did) as well.
