Don Terrill’s Speed-Talk

OK, I'm Wondering what the majority feel is the best sealant to use on head bolts going into the water jacket. And, do you change it up when head bolts are going into wet blocks using some Heli-coils? SBC 010 block from 72......... Just wondering. Going to be setting some heads down on a block this week. I know what I eused 20 years ago, wondering if there is anything new now that is any better than permatex sealant?

JohnnyB wrote:OK, I'm Wondering what the majority feel is the best sealant to use on head bolts going into the water jacket. And, do you change it up when head bolts are going into wet blocks using some Heli-coils? SBC 010 block from 72......... Just wondering. Going to be setting some heads down on a block this weak. I know what I used 20 years ago, wondering if there is anything new now that is any better than permatex sealant?

Loktite 51813 been around for 30 years but few use it..... The stuff worked back then and still does..

af2 wrote:Loktite 51813 been around for 30 years but few use it..... The stuff worked back then and still does..

How long does it take to set-up? I'd be surprised if it didn't set up between initial torque and the re-torque (if a person is retorquing after some run-time.)

I would likely use a Teflon-based thread sealer; the one I have in mind isn't fully cured for 24 hours--plenty of time for retorquing.

Loctite 592 PST locks and seals threaded fittings. Resists leakage, vibration loosening, moisture, hydraulic fluids, and diesel fuels. Lubricates threads for easy assembly and disassembly. Won't shred or wear like teflon tape. Parts may be repositioned up to 24 hours after application. Works to 400 degrees F. Suggested applications: Head bolts into through holes, oil psi sending units and sensors, oil and coolant lines, fuel fittings, rear axle fill plug, brake and power steering fittings.

I would think a Heli-coil could make for coolant seepage if the coil wasn't itself sealed to the block when it was installed. Might need to apply sealer under the bolt head to stop that leak.

I've used good old Indianhead since I was a pup FINE!

Stuff was made for this...

pdq67

Schurkey wrote:

af2 wrote:Loktite 51813 been around for 30 years but few use it..... The stuff worked back then and still does..

How long does it take to set-up? I'd be surprised if it didn't set up between initial torque and the re-torque (if a person is retorquing after some run-time.)

I would likely use a Teflon-based thread sealer; the one I have in mind isn't fully cured for 24 hours--plenty of time for retorquing.

Loctite 592 PST locks and seals threaded fittings. Resists leakage, vibration loosening, moisture, hydraulic fluids, and diesel fuels. Lubricates threads for easy assembly and disassembly. Won't shred or wear like teflon tape. Parts may be repositioned up to 24 hours after application. Works to 400 degrees F. Suggested applications: Head bolts into through holes, oil psi sending units and sensors, oil and coolant lines, fuel fittings, rear axle fill plug, brake and power steering fittings.

I would think a Heli-coil could make for coolant seepage if the coil wasn't itself sealed to the block when it was installed. Might need to apply sealer under the bolt head to stop that leak.

Schurkey, You are correct it cures in absence of air. But with studs and the very few that re-torque head bolts it is very good.
The people having rocker stud and head stud problems sealing will have none using the 518....
Also the 592 is also a very good sealer

Hylomar
(Rolls Royce Aircraft Patent)
seals both Antifreeze and oil and does not harden so bolts may be retorqued

The Teflon sealer works well if both the head bolt a block threads are very clean. The Aviation Permatex is what I used for years when building a lot of claimer motors when we did the bare min machine and prep work, but I still use the Aviation Permatex it does not fail me.

FWIW, I have found that the Purple cleaner cleans the threads very well if you soak the bolts for a few hrs.

Gov

af2 wrote:

Schurkey wrote:

af2 wrote:Loktite 51813 been around for 30 years but few use it..... The stuff worked back then and still does..

How long does it take to set-up? I'd be surprised if it didn't set up between initial torque and the re-torque (if a person is retorquing after some run-time.)

I would likely use a Teflon-based thread sealer; the one I have in mind isn't fully cured for 24 hours--plenty of time for retorquing.

Loctite 592 PST locks and seals threaded fittings. Resists leakage, vibration loosening, moisture, hydraulic fluids, and diesel fuels. Lubricates threads for easy assembly and disassembly. Won't shred or wear like teflon tape. Parts may be repositioned up to 24 hours after application. Works to 400 degrees F. Suggested applications: Head bolts into through holes, oil psi sending units and sensors, oil and coolant lines, fuel fittings, rear axle fill plug, brake and power steering fittings.

I would think a Heli-coil could make for coolant seepage if the coil wasn't itself sealed to the block when it was installed. Might need to apply sealer under the bolt head to stop that leak.

Schurkey, You are correct it cures in absence of air. But with studs and the very few that re-torque head bolts it is very good.
The people having rocker stud and head stud problems sealing will have none using the 518....
Also the 592 is also a very good sealer

if it seals with the absence of air,wont it cure in the tube??

Permatex 59235 High temp thread sealant. It is the only thing I have found that will reliably seal studs. All of the teflon based things I have used leaked at one time or another.

Mack wrote: if it seals with the absence of air,wont it cure in the tube??

The tubes are never completely full so it doesn't. Also why you can leave the lids off and they don't cure.

What about permatex 80632

Pipe dope
non hardening? yes, "remains pliable at higher and lower temperatures"

but how does it affect torque/ clamping force
you could bolt stretch some rod bolts with it and see how much torque it takes compared to moly lube or engine oil
Halomar is the best, everything else just sorta works

I'm not saying this is the correct sealant or even that it does what I was told, just sharing a story so don't shoot the messenger! When I was too young to know better, I just put the bolts in without any type of sealant and never had any problems. Of course that was only once or twice, just got lucky I guess. Then when I found out I was doing it wrong, I started using teflon paste and still wound up paranoid on every build, but no leaks. After ten years of using the teflon sealant, I took a side job grinding cranks at a local reman-shop and saw their head engine builder use red lithium bearing grease on the head bolts of every engine he built, except the TTY bolts. He just dipped the tip of the bolt in the grease and installed it. He said it was taught to him by an old timer that worked for Holmon-Moody in the 60's. I knew the guy he was talking about before he passed about 10 years ago. I don't know if he actually used that method at Holmon-Moody, but he did on the engines he built locally after he retired. Anyway, the grease is supposed to lubricate as well as repel the water from making its way up the bolt hole. I hate to change a process that works, but had to try it in a pinch once. It's a very quick and effective method, and when I freshened the engine two years later it was still in the same form it was the day I installed the bolts.

non fibered roofing tar would probably work just fine... I've used the black non-hardening permatex many times and never had a problem-always liked the fact it was non-hardening in the event I wanted to retorque the heads.

Permatex #2