ARP head stud kit question

Wotland · Post by **Wotland** » Sat May 05, 2012 7:51 pm

One guy here bought a set of ARP head stud kit for his new 4.6.

The seller advice him to use torque-angle method like with genuine stretch bolts

What He did

I sent mail to ARP to confirm this method with their studs but they don't yet reply....

Someone heard already we can use torque-angle method with ARP studs ?

When you see how stretch bolts work ( http://www.reinz.com/pictures/39-00129- ... -low-e.pdf )I doubt really same torque-angle method can be used with ARP studs.

mgbv8 · Post by **mgbv8** » Sat May 05, 2012 9:27 pm

I wouldnt do this with ARP.
Use the correct lube and torque to the book setting.

Using the 90 + 90 method might pull a stud out of the block??

sidecar · Post by **sidecar** » Sat May 05, 2012 11:19 pm

I use ARP studs, I used the correct lube on the washers and the threads and went for 75ftlbs on the long studs, I don't use the shorter outside studs. 75ftlbs is what V8 Developments go for, I think that it is quite a high figure,you could go for 70. (I used comp gaskets, I think they have more 'give' in them than 'tins')

unstable load · Post by **unstable load** » Sun May 06, 2012 6:24 am

mgbv8 wrote:Using the 90 + 90 method might pull a stud out of the block??

Probably would.
How some people get into positions where they can advise clients with info like this is beyond me at times.

ian.stewart · Post by **ian.stewart** » Sun May 06, 2012 6:38 am

I cant see the point of using bolts that are designated to be Torqued as stretch bolts, these studs are designed not to stretch.
Thinking about it logically, you have 2 different threads on the stud, 1 fine, 1 coarse, if working on the theory that either thread can turn, 90degs on the coarse thread will give you perhaps 0.4 compression on the head, and with the fine thread you may get 1/2 of that, if you get 1 stud that rotates on the coarse thread and the rest on the fine thread, you will get uneven clamping.
I think that makes sense,------ use a torque wrench .

Wotland · Post by **Wotland** » Sun May 06, 2012 8:04 am

unstable load wrote: How some people get into positions where they can advise clients with info like this is beyond me at times.

Agree with you and this "advice" was given by an well-know seller...

ARP recognize them-self their kit is not really suitable for 4.0/4.6 blocks.
It seems they are developping a new kit for later blocks.

sidecar · Post by **sidecar** » Sun May 06, 2012 8:24 am

Wotland wrote:
unstable load wrote: How some people get into positions where they can advise clients with info like this is beyond me at times.
Agree with you and this "advice" was given by an well-know seller...

ARP recognize them-self their kit is not really suitable for 4.0/4.6 blocks.
It seems they are developping a new kit for later blocks.

Just out of interest why is the kit not really suitable for a 4.6 block?

(Other than the short studs could not be fitted even if you wanted to use them)

bigaldart · Post by **bigaldart** » Mon May 14, 2012 6:35 am

Use ARP lube and torque to ARP specs, if it's a road car 70 lbs/ft is fine, on our engine we use a copper gasket so go right to the ARP torque which is even higher! The ARP figure will most likely pull at least one thread, so just helicoil it ! Should be ok at 70 though, take it up in stages, we used 40 then 60 then 70. Studs in block finger tight then just nip using an allen key, run a tap down all threads to clean them first. and don't lube the coarse thread into the block, just the fine one when you put the nut on.

Alan