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Discussion Starter · #1 ·
I'm about to install new cast iron heads on my new short block 350. I've read that the threads on all head bolts should be treated with plumbers Teflon sealant, Permagasket, or aviation thread sealant. The postings that talk about using the Teflon sealant suggest applying it to the bottom of the bolt heads as well as the threads to provide proper lubrication for torqueing the bolts. So... the head bolts that I have on order from Summit - Chevrolet Performance Head Bolts - appear to have some sort of sealant already applied to the threads. Looking for suggestions here... should I remove that sealant, and apply Teflon sealant to the threads and bottom of the bolt heads, or...? Thanks!
 

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Use the bolts as is. Add a drop of oil under the head of the bolt and you will be OK. Teflon sealer is for un sealed or used bolts.
 

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This is my experience and info I have read so you can do as you feel comfortable but I know with all those bolt holes going into coolant it is not fun having a leaking bolt. I have seen the TTY bolts that already have a teflon coating on them be used as is with very clean holes and with oil under the head and torqued to specs and they still ended up leaking sometimes but not all the time. I have used stock bolts arp bolts and studs as well. The best way I have seen for them to seal is I have read where some folks clean up the teflon off the bolts cause its a hit or miss deal for some and they put either teflon tape and use it that way or permatex no 2. I have used the teflon paste before with arp bolts and I have to say I never had good luck with that sort of sealing stuff. Best luck I have had is to leave the teflon that is already on the bolts and also add permatex no 2 or indian head on the threads as well and then get them all torqued down to spec and never had any leakers.
 

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I clean te bolts, wrap them in the cheap tape a few times, oil lightly and install 5lbs over torque spec. Never had a leak.

I use the tape soley because it's cheap and it works. Probably not by the book but it's cheap and it works.
 

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I'm about to install new cast iron heads on my new short block 350. I've read that the threads on all head bolts should be treated with plumbers Teflon sealant, Permagasket, or aviation thread sealant. The postings that talk about using the Teflon sealant suggest applying it to the bottom of the bolt heads as well as the threads to provide proper lubrication for torqueing the bolts. So... the head bolts that I have on order from Summit - Chevrolet Performance Head Bolts - appear to have some sort of sealant already applied to the threads. Looking for suggestions here... should I remove that sealant, and apply Teflon sealant to the threads and bottom of the bolt heads, or...? Thanks!
I like them coolant tight not just secure enough that no leakage occurs from under the bolt head but sealed well enough that there is no coolant penetration of the threads at all. So all the head bolts get a PETF plumber's putty coating whether they are factory sealant coated or not. This process extends to coating the female threads as well to insure that the action of installing the fastener pushes sealant ahead of the fastener's threads to prevent any seepage into the thread area period not just to keep it from leaking at the bolt head.

Bogie
 

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I prefer tape as well only because its retorqueable after a few hot and cold cycles, I dont believe in non retorquing head gaskets.

I use SS compatible tape since it contains nickel powder which acts as a solid lubricant in the thread and is a little thicker and more durable than standard PTFE tape, three wraps are are you need and its easy to clean up after removal.
 

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Discussion Starter · #7 ·
Permatex Nickel Anti-Seize Lubricant

Thanks for all the help. I'm looking at picking up some "Permatex Nickel Anti-Seize Lubricant", a high-temp compound with nickel and graphite. Can anyone tell me... this should seal the threads as well as lubricate them?
 

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As someone who has used many sets of these bolts for stock and mild performance builds my recommendation is to do as Bob says. Put a drop of oil under the head and torque them down. Just make sure the threads in the block are clean.

These are the same bolts used by GM on their crate motors and their record on leaky head bolts is pretty darn good. I've probably used 20 sets of these bolts with zero failures.

Everyone has their magic potions and everyone thinks their's is the best method so it's up to you which way you go. I can only speak from actual experience using them.

As far as today's head gaskets and re-torquing, that's a topic for another thread.
 

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I don't think anyone said their method was best, just a lot better than doing nothing, and pretty darn easy to do- be it permatex sealant, ptfe paste, ptfe tape, or super fancy plumbers tape.

Last time I bought the white tape from Home Depot I think it cost me around 70 cents, and one spool will do a LOT of head bolts.

Also remember not all head bolts come from GM, and that sealant put on it from the factory has a shelf life.
 

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I don't think anyone said their method was best, just a lot better than doing nothing, and pretty darn easy to do- be it permatex sealant, ptfe paste, ptfe tape, or super fancy plumbers tape.

Last time I bought the white tape from Home Depot I think it cost me around 70 cents, and one spool will do a LOT of head bolts.

Also remember not all head bolts come from GM, and that sealant put on it from the factory has a shelf life.
I wasn't pointing the finger at anyone but over the years on this forum the examples of magic potions are too many to list.

The OP referred to the head bolts as "GM performance" so that's what I'm referring to in MY answer.

How many sets of GM performance head bolts have you used? What has been your experience with them? I believe the sealant that GM uses is either Loctite Vibra-seal 503 or 513. It's pretty impressive stuff, look it up sometime.
 

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Discussion Starter · #12 ·
Nothing like answering my own question about whether or not Permatex Nickel Anti-Seize will seal the threads.... from the Permatex technical data sheet for the product, "Typical Applications": "...lubricate and seal pipe threads in acid environments, coat gaskets in high temperature applications,...". I would guess that if it seals such pipe threads, it should seal head bolt threads.
 

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Nothing like answering my own question about whether or not Permatex Nickel Anti-Seize will seal the threads.... from the Permatex technical data sheet for the product, "Typical Applications": "...lubricate and seal pipe threads in acid environments, coat gaskets in high temperature applications,...". I would guess that if it seals such pipe threads, it should seal head bolt threads.
You will be the first to try never sieze in that environment. I have that stuff on a shelf and would NEVER use it to seal head bolts, but I would and often do, use it to keep bolts from locking up- makes disassembly very easy.

I'd go with something that's been proven to work in that application, and costs less money, but to each his own.
 

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How many sets of GM performance head bolts have you used? What has been your experience with them?
exactly "0" I've reused stock bolts and used ARP, and occasionally stock replacement bolts from the autoparts store but God knows who made them.

Which is my point- most bolts are not GMPP bolts.
 

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Anti seize is not a sealant, don't expect it to seal a straight thread...tapered pipe threads seal on the root of the thread, totally different.

I have no doubt any sealant will work, I prefer tape only because there is no clean up issues if they are removed. Studs I seal in with Loctite non hardening sealant 518 and torque the heads on after to make sure it sets under tension.

Lots of ways to skin the cat and I'm sure the GMPP preapplied paste is good, I just hate having to clean the gunk out of the threads if they are removed later...studs are different and are rarely replaced if the heads come off.
 
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