Intake Manifold Thread Sealant

[Dante64]

Good Morning Gents, I pulled the intake manifold off to clean and paint before installing my freshly rebuilt carburator. consulting the Chrysler Shop Manual for my ’64 Newport 361, it mentions “non-hardening thread sealant”. Any past experience, one could send my way, would be greatly appreciated. You guys are a font of information and have helped me every time. Thank You and Cheers.
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[Big_John]

#2 Permatex is non-hardening. Honestly, I've never used a sealant on those bolts, but it can't hurt.

 

[Dante64]

#2 Permatex is non-hardening. Honestly, I've never used a sealant on those bolts, but it can't hurt.

Thank You John. I remember my water pump bolts had sealer on them when i was cleaning the threads.

 

[413]

Some engines will need sealer, most engines do not.
Blow by?
Crankcase pressure?

I would put it together dry and see if any oil comes up the bolts. If it does remove, clean and seal them one at a time.

 

[Dante64]

Some engines will need sealer, most engines do not.
Blow by?
Crankcase pressure?

I would put it together dry and see if any oil comes up the bolts. If it does remove, clean and seal them one at a time.

Good suggestion. I’m not experiencing any blow by or excessive pressure. Only mentioning it because the Chrysler manual stated it. Thanks 413.

 

[CBODY67]

Usually, on bolts which do not go into oil and water, no sealer is really needed. In those situations, the "sealer" could be considered to be "thread keeper cleaner". The #2 Permatex will also help maintain torque, where Permatex Blue Thread locker is not really needed.

In general, in reading factory service manuals, it can help to understand what sealers and such were in use, or non-use, when the manual was written. NOT in the current orientation of things. So considering "what came later" and when can be important. The older sealers and such can still be used, if desired. Some of the later high-heat silicone sealers can be better in many places, but not on threads.

Enjoy!
CBODY67

 

[Big_John]

Usually, on bolts which do not go into oil and water, no sealer is really needed.

The manifold bolt holes do open into the inside of the engine, so it could seep oil up through the threads. I wouldn't expect it to, but the possibility is there.

You can see the light through the first hole.

 

[413]

Yes intake bolts are open to the crankcase. SB and BB

 

[RemCharger]

Use a white pipe thread sealant like permatex or loctite brand. I like nice clean engines myself. Some are not too concerned.

 

[CBODY67]

BE SURE to read the FSM as to torque values AND if the threads should be "lightly oiled" or similar, as ANY sealer can affect the friction between the threads of the fastener and the material the fastener is being fastened into. Dry threads can mean more torque for a given retention force as "wet threads" can mean the opposite.

For example, if they recommend #2 Permatex or similar, that is what the torque values are based on. For liquid Teflon sealer, with less friction, it could be less.

Just some side issues,
CBODY67

 

[Dante64]

BE SURE to read the FSM as to torque values AND if the threads should be "lightly oiled" or similar, as ANY sealer can affect the friction between the threads of the fastener and the material the fastener is being fastened into. Dry threads can mean more torque for a given retention force as "wet threads" can mean the opposite.

For example, if they recommend #2 Permatex or similar, that is what the torque values are based on. For liquid Teflon sealer, with less friction, it could be less.

Just some side issues,
CBODY67

That’s an excellent point to consider. It never occurred to me that would affect torque. Thanks Brother.

 

[Dante64]

The manifold bolt holes do open into the inside of the engine, so it could seep oil up through the threads. I wouldn't expect it to, but the possibility is there.

You can see the light through the first hole.

View attachment 713372

Yes, I believe that is an issue with keeping a clean engine. Permatex to rescue.

 

[Milo]

I always use aviation sealer and never had a problem