I had the same issue with the arp studs on our car. I was in denial at first and replaced everything besides the studs because there wasn't a better stud on the market at the time.

From my experience, the magic number where these motors start to lift is around 700-750hp. I know some guys have been fortunate enough to not have it happen to them, but you have to understand that although the engine managements these days are very fast and precise. We are relying on reluctors and hall effect sensors to properly time the combustion event up to 8,000-10,000rpm. With that being said, there will be timing drifts no matter what. Timing drifts on low boost and power is manageable, but at 700+hp its a whole different story.

I've always told our customer.. "At these power levels, there is no way you can completely avoid knock, you just try your best to minimize the chance of it happening and make sure your parts can handle it when it happens"

I hope it is something small. I know snap-on makes a very nice pressure tester where you can test the cap as well. Give that a shot or just replace the cap with a new one. If the head is already lifting, pulling timing will only save you for a short period of time. Let me know if you need anything! good luck bud

 

I just installed ARP headstuds myself and I'm curious to see how it goes. My honda bolts could have been reused but I opted for the studs.

I'm curious how people are torquing down the ARP studs, I know of a few members some posting in this thread that have had problems with them and I consider them intelligent people but I'd love to have personally witnessed the head install.

ARP does make much better studs if you got big bucks of course but they're 5 times the cost or so as I recall.

So can someone who had problems with the studs including the OP tell me precisely how you installed them? I'm fully built for 800hp and I built the head as well. I'd be very surprised to see the ARP studs fail because my past experience with them has been great on motors making 400hp per liter or more.

-Greg

 

I have yet to use ARP on a OEM HG but I originally followed my supplied instructions with the studs torqued to 85ft/lbs with ARP moly lube on a IP 3mm headgasket. That blew within 5000kms

Next was a SCE 2mm copper headgasket sprayed with permatex copper spray and ARP torqued to the s2ki conclusion of 90ft/lbs with arp moly lube and then heat cycled and retorqued. That lasted about 7000kms and I am now going back to OEM HG

The head lifted twice with ARP studs. I think I will either be using OEM bolts or going with the new fullblown studs

 

I did the process that was given in the manual except I went to 90 instead of 85ft lbs for peace of mind. The fact of the matter is that ARP studs at this power level is borrowed time. We called ARP and they advised not to do over 500hp with this car but of course we all press our luck because "it has been done." in this case, tuning is not the issue but the equipment being used. If I have to pull timing away from the MBT I tuned to, that defeats the purpose of tuning the car for what it wants. I shouldnt have to tune to the headstuds capability. The fix for this would be stronger head studs. Like LJ said, they weren't available back then but now they are so that's what I'm gnna go with if the head is indeed lifting. The shitty part is that leak down tests don't lift your head so its not always accurate. More than likely, the higher level of coolant in reservoir isn't from a cap but a tiny leak of boost in the coolant system. This is the risk i was fully aware of so I'm not upset at all because I learned something again.

 

I've no doubts there's a serious problem with ARP on a non stock like I stated. 85ft/lbs and 90ft/lbs? Should be 95ft/lbs shouldn't it?........I expect with a better moly they came out with it would have changed ONCE but I don't recall 85 and 90 being the change. :eeeek:

Why don't you just use a stock HG and ARP studs the way they were meant to be used?

 

Peace of mind? That's not how studs work though, what made you "feel good" could have been the direct cause of your HG lift man. They are strongest at EXACTLY the amount they should be torqued too. The metal actually gets weaker as you over-tighten. You have to understand the types of clamping in different studs such as TTY (torque to yield) and such. I don't agree it's borrowed time until I see a proper install on a proper application. Seems ARP is blamed for user error in both application and installation too often.

ARP makes much better studs if you have to have more power, they're expensive though!

EDIT> Ah, not available then. Fair enough, still you were not following their installation nor application process correctly.

I just want to keep things fair before we quickly pass blame to ARP.

EDIT> I've read many articles and papers on the topic of fasteners. Here's one people should know just for kicks in example. Note there's more to nuts and bolts than most understand. http://www.enginebuildermag.com/Arti...uetoangle.aspx

 

Please everyone read both of these

1. http://arp-bolts.com/pages/technical_installation.shtml

2. http://arp-bolts.com/pages/technical_torque_us.shtml

Those should be fully understood before choosing a stud/bolt for your car.

Further good info but less important would be below:

3. http://arp-bolts.com/pages/technical_metallurgy.shtml

4. http://arp-bolts.com/pages/technical_design.shtml

 

Peace of mind? That's not how studs work though, what made you "feel good" could have been the direct cause of your HG lift man. They are strongest at EXACTLY the amount they should be torqued too. The metal actually gets weaker as you over-tighten. You have to understand the types of clamping in different studs such as TTY (torque to yield) and such. I don't agree it's borrowed time until I see a proper install on a proper application. Seems ARP is blamed for user error in both application and installation too often.

ARP makes much better studs if you have to have more power, they're expensive though!

EDIT> Ah, not available then. Fair enough, still you were not following their installation nor application process correctly.

I just want to keep things fair before we quickly pass blame to ARP.

EDIT> I've read many articles and papers on the topic of fasteners. Here's one people should know just for kicks in example. Note there's more to nuts and bolts than most understand. http://www.enginebuildermag.com/Arti...uetoangle.aspx
[/quote]

Do you know why I torqued them to 90? It's because everyone on here seems to have a different spec sheet for tq. Ive seen 80, 85, 86, 90, 95 etc. I wanna say mine was 86 so I went to 90. There any many people who have tqd to spec and still had issues. The issue is not the tq specs or whether or not I went over or under but the fact that they are weak studs for my application. I already stated that ARP themselves said not to run the amount of power I'm running so that in itself was enough for me to say okay I operated them outside of their normal limits. Just like this motor, it could blow at 700hp but hasn't yet. Maybe it will, maybe it won't but so far many of us are in the same boat of being shocked on how/why this motor is handling this haha. The old days of getting ARPs for added insurance apparently doesn't apply to this motor because it seems as if the stock bolts are just as strong if not stronger. The only reason why I used the ARPs was because I already had them in hand.

 

To the OP what head gasket are you currently running?

 

I am running the stock HG. I have had zero issues with the ARP's and 17 psi for the past year and half until now with 700hp.