Where to apply sealant

[cmcfaul]

Officially in the reassembly mode of my 2.4 rebuild. I did not split the case. Have the reseal kit with all the gaskets etc. Are there areas where I should use sealant? Additionally, are there areas where I should use Locktite? I am using all new hardware (nuts, bolts washers etc.).

Thanks

Chris

73 911 E

[lindy 911]

Base gaskets: Curil T or aviation gasket maker
Cam towers to heads: Locktite 574
Cam carrier, chain box, chain box cover: Locktite 574
Intake manifolds: Curil T
Bolts for fan shroud: Red Locktite
Flywheel bolts: Red Locktite

[E Sully]

Isn't red locktite a bit much for the fan shroud?

[YTNUKLR]

I have done this a few times. This is my method (no issues):

-No Silicone RTV anywhere- let's just get it out there - None!

Case perimeter- Threebond 1104/1194
Case main saddles - Loctite 574
#8 Bearing - Threebond 1211
Flywheel seal - Curil T

Base gaskets- Curil T

Cam tower to Heads - Threebond 1104/1194

Chain box to case and chain box to chain box covers - Loctite 518

Anywhere you are using a paper gasket besides valve covers - Loctite 518

Red Loctite on Head Studs - CASE side (and nowhere else) The next guy that takes the flywheel off the motor where you put red loctite is going to want to F-in' kill you (and that may be you, trying to kill yourself in the past). Or if you put it on the exhaust studs that go into the heads. Don't do it!

This is tried and true. It works well to keep the engine from leaking, and it comes apart with minimal fuss. Loctite 574 hardens and requires a razor to remove; it makes gaskets hard and brittle (and stick). Loctite 518 stays supple and fills large gaps when mating with gaskets.

[Flat6pac]

I use 574 on the bottom of the paper gaskets on the chain boxes and bottom of the covers.
Never, repeat never use red locktite....
Bruce

[cmcfaul]

Wow, glad I asked.

So I am clear, Loctite Red is for the threads. The other loctites are a type of form a gasket and supplement the paper gaskets.

Are the base gaskets you are refering to the brass gaskets at the bottom of the cylinders? You are telling me to use the Curil T on the bottom of the brass gaskets(between the gasket and the case). I did not split the case and am leaving all that alone

[cmcfaul]

Why not use 518 on the lower valve covers. I seem to always get some leakage there. Does it leave a mess when doing valve adjustments later?

Chris

73 911 E

[lindy 911]

I've had few problems with Locktite red on the bolts mentioned above. I think the end use of the motor has a lot to do with your choices though. If you are building a motor that needs frequent dis-assembly, the blue is a better choice as is something other than 574. But if you're building a motor that will stay in the car for the next ten years, I stand by my advice.

There is a thread here called "Ultimate Sealants" that gets to the skinny of it all. Since you said you weren't splitting the case, I stuck with the required procedures for a cylinders up rebuild. There will be infinite opinions here so look around.

[Walt Fricke]

Red Loctite is valuable for keeping the flywheel bolts where they belong in the 6 bolt 70.4mm cranks. An impact gun has no problems removing these bolts. They come right out as required.

However, if you are not going to spin the motor up to 8,000 rpm (or above), it is not necessary, and so shouldn't be done.

Walt

[cstreit]

Originally Posted by YTNUKLR

-No Silicone RTV anywhere- let's just get it out there - None!
.

Mechanics and future owners everywhere thank you sir. I think labor rates should go up based on every ounce of silicone used by the prior owner.

[TibetanT]

+1 with what Chris and Scott said!!

I am currently working on a 1978 3.0L and am finding RTV everywhere. What a mess...with little pieces floating around inside the case too. Wonder how the oil was flowing, huh?

[pirin911]

Hi to all:
I am in the process of my rebuild and can't find either the TB 1211 or the Curil T. What can be used instead for the cylinder base gaskets and the No. 8 bearing?

Thanks as always,

Francisco Soto

[lindy 911]

You can get both from Henry Schmidt at Supertec. I used Curil T on my nose bearing O-ring and it leaks. I used aviation gasket maker on the base gaskets and they do not.

Lindy

[Walt Fricke]

I use orange Loctite around the outermost part of the nose bearing (outboard of the O ring). No leaks, but then again maybe it wouldn't anyway.

I have never used anything on the base gaskets, and have never had a leak. Or at least not enough so there is a drip. Sometimes a little more dust/grime may gather in that area.

So there are lots of ways which can work (just as there are quite a number of sealants which will work).

And some which don't.

[pirin911]

Lindy:

Thanks for your quick reply. But I live in Puerto Rico and I think these sealants can't be send by air (because of flammability, I think). I was thinking about using Permatex 518 Anaerobic gasket maker (which I already have) for the nose bearing (between the o'ring and exterior part) and maybe TB 1194 in the cylinder base gaskets.
What do you think?

Thanks,
Francisco

[Henry Schmidt]

John was kind enough to post this picture a few years ago and it's how we've been sealing engines for years.


Outer case halves perimeter : Threebond 1104 or 1194

Bearing web surfaces: Loctite 574

#8 Bearing O-Ring: Threebond 1211

Case Thru Bolts: Dow Corning 55 on Green Viton O-Rings

Flywheel Seal: dry

Front pulley Seal: dry

Intermediate Shaft Cover to Case: o-ring Dow 55, gasket style 574

Oil Breather Cover to Case: Loctite 574

Cylinders to Case: Curil T

Cam Towers to Cylinder Heads: Threebond 1104

Cam Chain Housings to Case: gaskets Loctite 574

Cam Chain Housings to Cam Towers: gasket Loctite 574

Cam Chain Housing Cover to Cam Chain Housing: Gasket Loctite574

Gaskets: Thin coat of Loctite 574

[pirin911]

Thanks Henry, I saw that picture before, but would like to know what other brand can substitute the TB1211 on the no. 8 bearing? Maybe Permatex 518 Anaerobic gasket maker?

Thanks,
Francisco

[Henry Schmidt]

Originally Posted by pirin911

Thanks Henry, I saw that picture before, but would like to know what other brand can substitute the TB1211 on the no. 8 bearing? Maybe Permatex 518 Anaerobic gasket maker?

Thanks,
Francisco

Over the years we resisted putting any glue on the #8 main bearing but after measuring the case bore we consistently found that it was not round. Sometimes as much as .015 out of round. Boring the case is an option but most of the shops that do align bore only bore this bearing location if they are shaving the case and bringing the case back to standard.
We tried using a slightly larger o-ring but finally succumbed to the need for a consistent technique.
To answer your question: there are probably many sealants that will work for this application but to date ThreeBond 1211 is the best we've found.
Good luck if you choose to experiment. Let us know how that goes. We are always looking for improved methods for assembling these old engine.
Cheers

[tom1394racing]

Why would it be necessary to put any sealant on the bearing saddles?

These is no leakage path and the sealant should not stabilize the saddles.

I have been told it should not be done.

[Henry Schmidt]

Originally Posted by tom1394racing

Why would it be necessary to put any sealant on the bearing saddles?

These is no leakage path and the sealant should not stabilize the saddles.

I have been told it should not be done.

I have articulated and documented the theory of shear resistance offered by LocTite 574 flange sealant. I have illustrated in previous posts the movement called shuffle that occurs where the case halves come together at the main webs. There is absolutely no down side to properly applying Loctite to the main webs.
The choice is yours.

One additional thought: Shuffle is a real issue in a high performance Porsche engine that can be best addressed by methods like shuffle pins or hollow dowels. That said, anything that can add to the stability of the engine platform is a good thing and we have first hand experience that gluing the webs reduces shuffle.