The stud, not the nut. What is the torque you guys use? 20 ft lbs? 60 ft lbs?

 

Since they are not stock parts, what does APR recomend?

 

Returning them, and getting Simard to make you a set.

 

ok thanks,
I've used these before before with good results.

Imre good idea.

Has anybody else run a torque on the head studs of a 16v?

 

Pretty sure you are one of the few that have had any luck with them.
You might want to do a search on them, it seems several of them have failed.

 

ARP's I have used (but on steel block motors) go in finger tight (or 1/8 of a turn with the hex wrench on top). You do not want 'crank' them down (Studs). Put the stud in dry . Use the ARP lube on the nut.

But search for the ARP usage on the 928s. Some people claim they do not work well with Al blocks.

I have never personally used ARP studs on Porsche engines, but on the Mitsubishi motors I have built they are top rate.

 

I've used the ARP under some pretty hard use with no problems.

 

I thought Greg Brown had some issues with them, maybe I spoke to soon.
I have used ARP bolts and studs for American stuff with no issues.

 

I concur, never had any trouble in a 928 engine, I used the cold torque technique that is used in many racing circles, I did in fact see a NASCAR study on this, it was able verify the extra clamp force it can provide.

To answer your question about how to install, don't bottom them out. In fact when you go to install, get all the studs at the same and correct height you will see that installed height will not bottom the stud out. Try to ensure the threads in the block are clean too. The studs should screw in easily.

I coated my studs with lanolin (sheep wool grease) so that they have some corrosion resistance, I have pulled out studs from the factory and they were so corroded that they almost broke removing them despite me heating the block etc along with various other measures to try and loosen them.

Some studs these days have an allen key head to hold them in place while they are initially torqued. I use them with their hardened washers and multi point nuts.

 

I've not tried these on a 928 engine. I was never able to make them work on 951 engines and had much better results with the Porsche pieces. I believe that Chris Cervelli (Chris is way, way smarter than me and worked extensively on the 951 engines) also came to the same conclusion. We communicated about this, at length, and we came up with the idea that the ARP hardware was of such high quality that it didn't "stretch" enough to properly keep the head "clamped" onto the block.

I have no "raw" data to support this idea. Just a lot of failed head gaskets which made us try and come up with an idea that explained the problem.

ARP seemed to think that the problem was that we were not going back and retorquing the studs after the engine was warmed up, the first time. Note that the proceedure to be able to retorque the head (on a 16 valve engine) requires removing the cam carriers. Not all that much fun on a 928 engine. (Understatement.)

The 928 engine seems to have a much lower percentage of head gasket failures than the 951 engine and these pieces may work perfectly, in this application. However, if you read the ARP literature carefully, I think that they do still strongly suggest retorquing the hardware. If that isn't enough to scare you away from using this stuff on a 928 application, you've got way more time on your hands than I do.

 

I could have sworn you had some issues with the studs, thanks for setting me straight.

 

Here is where I got that from, in this thread you were asked "Why not use the ARP studs?"

I have taken out the extra stuff, so this is the answer you gave.

 

Steel being hard is easy to do and is not a sign of high quality.

There's no way that a mass produced aftermarket stud is going to be able to clamp reliably through the range of heat changes after being heat treated to production averages and installed by various shmoes using a variety of torque wrenches.
This is a recipe for broken parts and head gasket issues. These things get installed to horribly inadequate tightening amounts and when the parts break it's always something else blamed because nobody understands fasteners.
"Why it must be such amazing power building skills that things break, if I didn't smartly use ARP studs it would be even worse!"

 

Mike - Are you still making your head studs? I may as well use them as the same block has your main studs. I'll take out the arp studs somehow, maybe one at a time or something, and replace them with yours. I also need the rest of the clutch stuff - I think its just the hydraulic throw out bearing casing. I have to find some more stuff here to sell to pay for your shiny metal car parts (crack cocaine).

What is your torque sequence for your head studs?

 

Mike Simard, don't you offer a head stud alternative to the factory studs and ARP? Would you mind explaining ( or linking ) what makes them superior?

Thanks