12mm vs 14mm head studs

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j-rod

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At what level (hp, boost, etc) will 12mm studs not provide enough clamping force with fire-rings to keep the head on?
 
i think some are running a 9/16 stud.less meat taken from the block.there are also other options besides fire rings as well.some food for thought
 
rawdog said:
i think some are running a 9/16 stud.less meat taken from the block.there are also other options besides fire rings as well.some food for thought
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I have seen 9/16 ARP and 14mm on Haisley's site...can't remember the manufacturer right now.

Head is already fire-ringed; block will be soon. What do you have in mind?
 
Either is fine as long. I run the 14mm A-1's from scheids with .105 firerings cut in the block only. My brother runs 12mm ARP's with just a marine hg and my buddy Bryce runs 12mm ARP's with .105 firerings and never had a problem. We all run single turbos though. I think twins and drive pressure is where **** dont hold. I know Lethal injection 3.0 puller runs standard ARP 12mm studs but of course decompressed plays into account here. If you want to run more boost than most single s400 turn (55-65) then deff. go with 14mm. Dont do the high priced 12mm studs.

Tim
 
Because of the price for one and two because if you need that kinda clamping force, then do it right and go 14mm. The 625's in my opinion are harder than the block material for the amount of thread contact area and as a few have posted on here, strips the threads out of the block. Plus i have seen the studs themselves snap into because the are such a hard material. 14MM distributes the clamp load over a greater area. Just my opinion though.

Tim
 
ILLINOISRAM said:
We all run single turbos though. I think twins and drive pressure is where **** dont hold. I know Lethal injection 3.0 puller runs standard ARP 12mm studs but of course decompressed plays into account here. If you want to run more boost than most single s400 turn (55-65) then deff. go with 14mm.
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That is where my thoughts were Tim.
 
14mm and 9/16 also take material out of the block and you get closer to the cylinder walls, which can lead to cylinder failing much sooner. They both have good and bad points. I wouldn't go 14mm I would go ahead and go 9/16"

There was a guy making 13mm studs, you just ran a tap down the 12mm hole.
 
zstroken said:
14mm and 9/16 also take material out of the block and you get closer to the cylinder walls, which can lead to cylinder failing much sooner. They both have good and bad points. I wouldn't go 14mm I would go ahead and go 9/16"

There was a guy making 13mm studs, you just ran a tap down the 12mm hole.
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Why are you saying go 9/16"? They are the larger of the two.
 
Not to mention there is not a 9/16 12v headtsud set. Its something you have to custom order. I dont think the little differance in removed material would make a diff. Hell, you drill and tap the mainstuds for 14mm. I cant imagine with all the money and reaearch scheids, haisley and other have spent that 14mm mainstuds was not needed.
 
ILLINOISRAM said:
Not to mention there is not a 9/16 12v headtsud set. Its something you have to custom order. I dont think the little differance in removed material would make a diff. Hell, you drill and tap the mainstuds for 14mm. I cant imagine with all the money and reaearch scheids, haisley and other have spent that 14mm mainstuds was not needed.
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Not that custom I am saying that the 9/16 studs are cheaper in the long run if your going to go larger. Most machine shops have the 9/16" tapping ability, and the 9/16" is a standard stud. You need to choose the stud on what your trying to do.

If your worried about cracking the cylinder go with a 12mm 625. If your worried about pulling the threads out go with a 9/16".

Also if your boring the cylinder larger it might be a reason to stay with a good 12mm.
 
zstroken said:
14mm = .551
9/16 = .563

Your talking about 0.006" larger in radius
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Yes I know the difference in radius. I did not know right off hand that the 9/16" were cheaper...you made the comment to run 9/16" and the next thing you said was about getting too close to the cylinder wall, so I thought you were suggesting the smaller of the two for that reason.

At this point, I'm not worried about cracking the cylinder, and I should be at standard bore. Just getting an idea what I could need to hold the head on.
 
j-rod said:
Yes I know the difference in radius. I did not know right off hand that the 9/16" were cheaper...you made the comment to run 9/16" and the next thing you said was about getting too close to the cylinder wall, so I thought you were suggesting the smaller of the two for that reason.

At this point, I'm not worried about cracking the cylinder, and I should be at standard bore. Just getting an idea what I could need to hold the head on.
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Yea I was a little abiguous there.

12mm 625's is what I used. Higher resale value. LOL!
 
There is not a application for the suds so that makes them custom. You need three different sizes studs and hardware to go with. Were do you get this stuff at? Are you talking making your own studs? Further more, people that need more than standard 12mm studs are building motors and having machine work done. Whats one more step to do it right?

Are you saying that machine shops only deal in standard thread stuff cause my three shops around here didnt have any problem doing the 14mm.
 
ILLINOISRAM said:
There is not a application for the suds so that makes them custom. You need three different sizes studs and hardware to go with. Were do you get this stuff at? Are you talking making your own studs? Further more, people that need more than standard 12mm studs are building motors and having machine work done. Whats one more step to do it right?

Are you saying that machine shops only deal in standard thread stuff cause my three shops around here didnt have any problem doing the 14mm.
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They aren't customs studs you just order the 9/16" stud lengths you need.

I suppose if you can't measure the length of a stud then it would appear to be rocket science.

I am not saying that machine shops only deal with english, but almost any shop will have the standard stuff. Not all will have the 14mm.

Your drilling and tapping, drill for the cheaper stud. Last time I checked the 9/16" were well under $600, last I checked the 14mm were in the $700+ range.
 
I can measure thats not what i was asking. I was asking if you are calling ARP and ordering from them or going to fastenal and getting grade 8 fine thread ready rod and making them yourself. I think that is a logical question. Any machine shop that works on motors should have metric tap set. If not they are not a good shop to deal with. That would be like a mechanic only having standard tools.

600 to 750$ is worth it in my opinion to get studs that are meant for our motors, comes with good hardware and packeaged up nice and neat so i dont have to run around town or make phone calls for **** somebody allready did. I have wasted more than that on lapdances .LOL

Tim
 
ILLINOISRAM said:
I can measure thats not what i was asking. I was asking if you are calling ARP and ordering from them or going to fastenal and getting grade 8 fine thread ready rod and making them yourself. I think that is a logical question. Any machine shop that works on motors should have metric tap set. If not they are not a good shop to deal with. That would be like a mechanic only having standard tools.

600 to 750$ is worth it in my opinion to get studs that are meant for our motors, comes with good hardware and packeaged up nice and neat so i dont have to run around town or make phone calls for **** somebody allready did. I have wasted more than that on lapdances .LOL

Tim
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No the studs are ARP 9/16". For making a phone call and spending 5 minutes with a tape, seems like the $150 can be used somewhere else if need be.

However I chose the 625+ 12mm because I was worried about cylinder cracking. The price I got on them, actually made them cheaper than the 14mm if you figure in the machine work, and probably about the same as the 9/16"
 
zstroken said:
No the studs are ARP 9/16". For making a phone call and spending 5 minutes with a tape, seems like the $150 can be used somewhere else if need be.

However I chose the 625+ 12mm because I was worried about cylinder cracking. The price I got on them, actually made them cheaper than the 14mm if you figure in the machine work, and probably about the same as the 9/16"
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I agree that total price of studs and drill & tapping is equal to the 625's But i still think that if you need more than standard 12mm, then you block is going to be at the machine shop anyway so why not take care of it right there.

Even in a budget competition motor build of 10k, whats another 150 bucks.

Do you have actual proof that 14mm weaken the cylindar making them prone to cracking? My brothers motor cracked the number one cylindar right by the front left stud looking from the front with standard 12mm arps. I personally think if that happens it was its time no matter what studs are in it.
 
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