TwinTurbo.NET: Nissan 300ZX forum - Re: Re: Re: Re: Lets set a few things straight
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Subject Re: Re: Re: Re: Lets set a few things straight
Posted by Kyle(Houston) on September 14, 2017 at 6:16 PM
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In Reply To Re: Re: Re: Lets set a few things straight posted by Scott ZShack Taylor on September 14, 2017 at 01:53 PM
Message :“I don't believe z1 ever claimed they were selling the ARP2000 bolts in their kits. I could be wrong though.”
:Yes, they told me over the phone they where 2000’s Back when I first started purchasing them from them. Even if they didn’t, anyone looking at buying Studs may look at ARP’s website first and know that ARP only offers 1 head stud kit for the VG. This would lead a person to think they were buying 2000’s. This is a little deceitful at best.

Well as I stated before, I have been selling the ARP8740 for 18-19 years now. LONG before ARP finally came out with their ARP2000 kit at SEMA in late 2013. I think it was early 2014 before they were even readily available. So companies like CZP and Z1 were selling them a long time before the ARP2000 kit was released. Now after the ARP2000 kit was released and they claimed their kits were the same then I have no comment on that. I have never claimed my kit was ARP2000.

:“Yeah those are not the part numbers I use or have been using for at least 5-6 years now”
:Care to share your part numbers? Pretty sure those part numbers are the only option for 8740 in our sizes. I could be wrong

The studs are the same. I was referring to the nuts and the washers. I have been using the "custom" .995 washers(Part#200-8792) and bigger flange nuts(I will keep that close to vest for now) since about late 2012.

:“The 8740 have a longer thread depth and go into the block deeper then the ARP2000. In the picture you provided it certainly looks like they would be very close to the same height once seated into the block”
:Yes they seat into the block a little further due to the undercut, but the installed height difference is 5.5mm. This means 5.5mm less useable threads.
:Here are the measurements of properly installed ARP 8740 studs. This is the longer studs. I think we may be having a misunderstanding of my intent about this. I will try to explain. Over my years on Facebook and in person, I have seen numerous individuals rebuild a VG without a proper block cleaning. This coupled with not chasing the threads in the block has led to them installing the studs too shallow. When they installed them “finger tight”, they thought they fully seated them when they did not. As you will see in my diagram below, the 8740’s only have 7mm of wiggle room before the nut starts to lose threads. This is less with a decked block and head (obviously). With a thread pitch of 1.75mm the nut will get 1.75mm closer to running out of threads with each full turn.
:While I know that an experienced person such as you and I would never have this issue, my write up was addressing the general public. I was simply trying to clarify how to install the studs properly and the differences between them. I even said in the write up that if you back the stud out too far it will run out of threads. I didn’t say it would if installed properly.

Ahhhhhh I see. So for unprofessional hacks? I chase all the threads on every block I do and make sure the studs are fully seated. I thought that was SOP but maybe I am wrong.

But with that said. You forgot the 1.1mm head gasket in your measurements. So really this is what we are looking at

70.5mm head thickness + 1.1mm head gasket + 3mm washer = 74.60mm minus the 66.5mm to the bottom of the threads = 8.1mm of usable threads.

And just a quick correction for you. The threads that thread into the block are 1.75. The threads that the nut end have are 1.25. So it would take 6.4 complete turns before you got close to the bottom of the threads. I know when I torque down heads each of the three steps is only about 1/2-3/4 of a turn to hit the next torque spec.

:“Where is there a lack of thread engagement??? If you are claiming the top threads, I would like to see proof of that, please. Until then I will stand by my statements.”
:Did you forget about the short bolts on the vg? You have to go off the torque specs of your weakest bolt. The short bolt has roughly 3 full turns less threads on it compared to the longer bolt. I assume since you sell parts you should have both in stock? Compare the threads between the short and long bolts and the difference in thread count. Or do I need to provide those measurements for you as well? Lol

Nope. I have them.

Short bolt = LaZy Link

Long Bolt = LaZy Link

The top threads are exactly the same. And of course the short bolt is shorter to fit in the short hole in the block

Here are the nuts screwed down.

Long look = LaZy Link

Close up = LaZy Link

In my 18+ years of installing the studs I have NEVER seen that much thread sticking out the top of the nut where I would think it was bottomed out. Be it installed by me or sent to me from another shop or customer.

:this is why ARP lists the tq as less than what the longer bolt can handle. You say ARP2000 can go to 125, yet ARP lists in their instructions that you so adamantly like to reference, to tq their ARP2000 to 100FtLbs.

Interesting enough. You are the one who says 120 ft/lbs on the ARP2000 is fine. Both on your web page and in this post.

So your claiming that you tq your 8740’s to more than what ARP says to tq their better 2000 bolts to? Maybe you know more than the manufacturer does about their parts?

Well there is that idiot factor that I am sure ARP puts into all their specs. How many shade tree mechanics have torque wrenches from Harbor Freight that have never been calibrated? I am sure ARP gives at least a 10-15% leeway for the idiot factor. I know I get mine calibrated once a year.

Also, please provide evidence of your TQ specs for the 8740’s. The whole reason we ended up calling them about it is because the information is not on the web.

I did. I showed you the chart that shows that the M12 ARP8740 can be torqued to 112 ft/lbs. You are using the same chart to say the max torque is 125 ft/lbs on the same M12 ARP2000 studs and they can easily be torqued to 120 ft/lbs, no??? I typically only do 100-105 ft/lbs on the ARP8740 with my calibrated torque wrench.

:Again I will tell you that ARP said absolutely do not go past 80 FtLbs on the VG with 8740. They have seen the treads roll at 83FtLbs. And also that if they have gone past 83FtLbs, then you have now torque to yield. Meaning do not reuse the bolts again. I’m sorry if you don’t like to hear this information but don’t shoot the messenger! You are welcome to contact them, tell them exactly what you are using and what you are torquing them to and see what they tell you. Ask for Al his ext is 204 when calling the main ARP number. He is a great guy with a ton of knowledge.

Since you have done all the research and are on a first name basis at ARP, why are YOU not following their directions??

You are saying the ARP2000 can withstand 120 ft/lbs no problem. Here is a direct quote from your site:

"The REAL ARP2000 studs can be torqued to a maximum of 125 ft lbs before reaching the studs yield. Since many VG builders are torquing the L19's to 120 FT/Lb's successfully, there is no reason an ARP2000 can't be torqued to the same level."

You say the ARP8470 will roll the threads at 83 ft/lbs and the ARP2000 are only 10% stronger. That would mean the ARP2000 should roll the threads at roughly 91-95 ft/lbs by that logic.

Per Al @ ARP, what is the roll ft/lbs for the ARP2000 since that set also comes with a short stud???

:“Prove me wrong. The L19's and E85 builds have been being done now for probably 9-10 years. I have never heard of a L19 failure due to running E85. Until it becomes an issue or we can get 625+ studs for the VG30 platform; I will continue to recommend L19's for guys shooting over 650-700ish”
:Maybe you should re read my write up. I expressly stated that this has not happened (yet). But why would you want to risk it?

I would say that ~10 years of many cars on many different platforms running L19 head studs and not ONE single case has been seen is pretty strong evidence. IMHO

There is no need to run L19’s. Other platforms are running 2000 to more than double what we have ever made in the vg to date! Pretty much every engine builder and AL at ARP would tell you that if you are lifting a head with 2000’s then you are doing something wrong! Again in case you missed it, which it seems to be a common issue with you here. His extension is 204.

Again by that logic, if ARP2000's can hold up to lets say 1500Rwhp. That would mean the ARP8740 could hold at least 800Rwhp. Even at 80 ft/lbs vs 100 ft/lbs final torque spec, as you say ARP says is the law. That is only a 25% difference in clamping force. So even if the ARP2000's tapped out at 1000Rwhp you would be fine with ARP8740's to 750rwhp. Just talking logic here....

:Try to follow the logic here, If you can TQ an L19 to 120, (which is likely higher than what ARP would say to go to on the VG) without issue, then you can tq ARP2000 to the same 120. They both have the same yield point of 125 FtLbs! What is good for one is good for the other!

This is where your logic is flawed. You say the yield point of the ARP2000 is 125 ft/lbs which matches up to what ARP has listed on their site for the 12mm stud. So you claim 120 ft/lbs is fine for them even though ARP says 100 ft/lbs. And then you hammer me about the ARP8740 only being capable of 80 ft/lbs(even though the site says 112 ft/lbs for the 12mm 8740 studs) because 300zx and the short stud. But doesn't the ARP2000 kit and the ARP L19 studs also have a short stud??? Would that not mean that the yield point listed on their site would be greatly reduced as you claim the ARP8740 studs are??

So why not use the 2000 that is not vulnerable to embrittlement? And yes you can get CA625+ custom made from ARP. So there is no reason to ever use L19! But unless you fix the issue of the smaller bolt on the VG, or go to a larger diameter stud, you will not benefit from the added tensile strength of 625+ anyway!
:Direct quote from my write up…. “The ARP 2000 yield strength or the point in where the metal will stretch is 200,000 psi. L19 is 200,000 - 230,000 psi. Both will not reach yield until 125 Ft Lbs of torque or higher. The tensile strength or the point at which the bolt will break is higher on the L19, but both are still plenty high enough that if you ever broke one, it would be due to the engine operating out of an acceptable operating parameter! IE excessive head pressure or detonation etc.”
:Again, both will place the same clamping force on the head. L19 will hold a little more before snapping but as I and many others have said before, if you are breaking a 2000 stud, you have way bigger issues than tensile strength!

That whole statement is a contradiction. See my above statements

Kyle "Grumpy Bear" Puckett
Import Parts Pro
Phone: 281-288-0700
AIM: KyleatIPP
Yahoo: KyleatIPP

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