What sealing procedure to use for ARP head studs in water jackets?
 

I have seen plenty of horror stories about problems with leaking head studs that extend into water jackets instead of blind bolt holes. I have seen some using the ARP sealant, others using the 3M teflon thread sealant, and some even using other stuff like aviation sealant (the brown brush-on stuff). From what I have read, a lot of the success / failure hinges on thorough cleaning of the threads in the block and on the studs. I intend to do this, but still do not want any surprises.

It seems really strange that I read so many issues with the studs, but relatively few problems when using bolts. Is it an issue of the threads of the studs having pulliing forces applied when the heads are torqued down after they have taken a set, or is it the fact that most of the time when you goop up the bolt threads, some of the sealant ends up under the bolt head and perhaps gives an extra measure of sealing? I actually had one local race engine builder tell me that he puts a little bit of sealant under the nut heads when he installs studs for extra insurance. However, ARP recommends using their thread lubricant to get consistent torque readings.

Not sure how I need to proceed on this. Would like some input from others who have had success with studs on a 454 block. Would especially like to hear from some of the pros, but I understand that a lot of those guys are building big boy engines that have the blind holes. Also, I have always wondered how you avoid leaks when you go back to retorque the heads after initial run-in, especially with bolts!

I guess my thread got buried! ;)

Anyone out there successfully running studs on a 454 or 489? There is enough out there on the web about leakage issues with them that it is making me second guess using them. Might go with ARP bolts, although Bob M., who sold me the aluminum heads that will be on it, highly recommends the studs for their superior and more even clamping force.

I have instal them last summer without any problem on aluminum head, this year i reuse the same stud with the same procedure with arp stud sealant and i have found today that i have one stud leaking outside the valve cover, i am prety sure that is not the only one, i need to take a look under the valve cover.

If i find some milky oil anybody can tell me what is the solution to fix that, i hope there have one solution without disasembling the head.

I did the studs on my HP500s with pipe sealant in a tube I got from the Home Depot. It is resistant to virtually everything and seals very well. About 5 bucks a tube.

i use leak lock,put it on the threads and torque them before it starts to dry,app 45 minutes,i used to use arp thread sealant but the leak lock is much better.

Are you using the one with teflon (leak lock gold) or the standard leak lock?

I will try that product on my leaky stud

Thanks for the input

Like Mike says, go with the leak lok stuff. Its awesome stuff.

Teflon pipe dope is made for NPT threads, which the studs are NOT. I have used Anaerobic sealers as well. Not to be confused with regular RTV. A anaerobic sealer is like, Ultra Grey, Right Stuff, etc. There is a difference here. Go clean up a couple old bolts. Smear some Ultra black, or Ultra Blue on one bolt, then do the other bolt with Ultra Grey, or Right stuff. Let it cure overnight. You'll clearly see which one seals better. Ive had "right stuff'' stick to the base of the bolts before, and you pretty much need pliers to pull the excess ball glob off the base of the bolt once its cured. Regular RTV will come off with your finger nail. Basically, if the sealer smells strong like vinegar, it needs air to cure. The others will cure absent of air. I used Right stuff black on my head studs on both my 468's last year. So far, no leaks on any of the studs. Used Ultra Grey on a few boat engines in the past, no issues with those either. The "right stuff" is superior to other sealants, not only because it just seals good, it is much more impervious to oil on the surface when sealing, than a regular RTV. Theres a reason it costs much more, but worth it IMO. Hard to explain, but to me, Right Stuff is more along the lines of 3m 5200, and Ultra black is more along the lines of weatherstrip adhesive.

When I installed my studs, I used some brake clean on the threads in the block, and on the new studs, to remove any oil. New studs do have a little oil film on them. Blew it dry with a air gun, dabbed a little sealer in the block holes, and a little on the stud threads. Once threaded in finger tight, I used a q tip to remove any excess that builds up around the base of the stud. You don't want it to be a globby mess there.

Wouldn't your HP500's have blind holes for the head bolts?

I've never had a leaky stud and use aviation sealer and ensure they are torqued promptly after stud install. I think the reason I have good luck though is I run closed cooling with a 7psi blowoff cap to a reservoir. So if I were running sea water through the engines and was concerned with studs leaking, I might consider installing water pressure blow off valves to limit the water pressure spikes.

Right stuff is realy good i think i will try right stuf to fix my leaky stud.Next time i will use right stuf for stud for sure.