head stud seal and install

[aussie merc]

lets reignite this old debate im interested in your thought and reasons why ? Have seen several different approaches to this 1st sealant loctite 577 loctite 567 even loctite 515 permatex No2 non hardening and even teflon tape then we get into installing studs have seen quote rangeing from finger tight and then upwards in varying torques from 10 to 30 FTLBS even seen 1 person only install 2 studs place gasket on block then head and to proceed to install rest of studs through the head then removing the first two applying sealant then reinstalling Your thoughts

[RalphM]

Always used this on Flathead studs.

[Bored&Stroked]

I use a PTFE gasket sealer from ARP. I believe it is important to put the studs in and let them SET for awhile - before running the engine. I do like the ARP studs in that they have a place for a HEX/Allen key in the end of them. This makes it possible to install/remove them with the head on. For anybody who has struggled with studs and aluminum heads (seizing), this makes a lot of sense. Also, the ARP studs do not stretch (much) - so your torque values hold up.

Andi-Seize: I always put anti-seize on the sides of the studs before I put the heads on and I use correct ARP lubricant on the nuts/washers (fine thread side) to ensure that I have good torque readings.

Moroso Ceramic Seal: Given that in some cases the coarse block threads are a bit worn through rust and potentially incorrect taps being used, you still might see some "weaping/leaks" on some studs. Due to this, when I originally fire up a new engine (and before any anti-freeze or other water adders), I run a can of Moroso Ceramic Seal through the engine during initial warm-up. This is a great insurance policy in general for a newly built flathead. Sometimes I do it twice (2 sessions).

I highly recommend this procedure for helping to prevent head-stud/bolt leaks and also to potentially help prevent a small leak problem with a repaired crack "iron tight stitch" or sleeve in the machining process.

[Manuel]

Apparently the Holden stud sealer is supposed to be good.

[48-710]

Manuel,
Best of luck finding any of that. I have been told that GM sealer ,as we knew it ,is no longer made.
Regards Gary

[Flathead Fever]

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Supposedly the threads in the block were a special interference fit, that's what originally gave the studs their seal. If you run a modern tap through each one of the holes you can destroy that interference thread. I've seen two people do that and end up with all most all of the studs seeping even with the sealer. It's got me so paranoid, I won't run a tap through the block.

[corvette8n]

I haven’t used this on any block yet, still working on getting some broken studs out, not sure if these thread chasers would upset the interference fit like a tap.

[rockfla]

Can't preach this item enough. I learned about it from one of my customers that was rebuilding a pair of super high dollar, high tech air compressors for the U S Navy here at the local NAS Base and the engineers specifically spec's this for all the fasteners used on the compressor. Top notch stuff.

[alexiskai]

Originally Posted by Flathead Fever

Supposedly the threads in the block were a special interference fit, that's what originally gave the studs their seal. If you run a modern tap through each one of the holes you can destroy that interference thread. I've seen two people do that and end up with all most all of the studs seeping even with the sealer. It's got me so paranoid, I won't run a tap through the block.

Not sure about V8s, but on the Model A, the block threads are a Class 3 fit. It’s not interference but it’s very close. Specifically it is much closer than standard taps and chasers. ARP makes a Class 3 chaser that I use to clean Model A block threads.

[tubman]

Originally Posted by corvette8n

I haven’t used this on any block yet, still working on getting some broken studs out, not sure if these thread chasers would upset the interference fit like a tap.

To be sure, I use an 8BA head bolt with 4 grooves cut into it.