The Complete Engine Sealant Thread...

[Focker]

Originally Posted by Henry Schmidt

YamaBond and HondaBond are both made by ThreeBond. Check their data sheets for specifications.



We've been building engines using this technique for over twenty years.
That's nearly 200 911 air-cooled engines with stellar success.
Have others been successful with varying technique? Of course. We just offer our experience so first timers can have the best shot at success.

Pelican Parts offers the Supertec Case Sealant Kit with everything you need in one place.

Thanks Henry. I normally get everything shipped to Washington state then drive across the border to pick up, with the 'rona the borders are all closed and I don't think they ship the sealants across the border.

I have the Curil T and Loctite 574 already, but came across this thread and thought since I haven't assembled the motor yet I might as well take the advice of the experts in this thread. Well, maybe not all the "experts"...

[Privateer383]

Same list as previously posted by others, except I added the return tube o-ring lubricant as recommended in one of Henry Schmidt’s previous posts.

Outer Case Halves: Threebond 1104 (now 1184)

Bearing Saddle Surfaces: Loctite 574

#8 Bearing (balancer end) O-Ring: Threebond 1211 (now 1215)

Case Thru Bolts: Dow Corning 111 on Green Viton O-Rings

Flywheel Seal: DRY

Balancer Seal: DRY

Intermediate Shaft Cover to Case: ThreeBond 1211 (now 1215)

Oil Breather Cover to Case: ThreeBond 1211 (now 1215)

Cylinders to Case: Curil K-2 or ThreeBond 1211 (now 1215)

Cam Towers to Cylinder Heads: Threebond 1104 (now 1184)

Cam Chain Housings to Case: Threebond 1104 (now 1184)

Cam Chain Housings to Cam Towers: Threebond 1104 (now 1184)

Cam Chain Housing Cover to Cam Chain Housing: Threebond 1104 (now 1184)

Gaskets: Thin coat of Loctite 574

Oil return tube O-rings: Dow 55 o-ring lubricant (alternate: Dow 111).

[Focker]

Originally Posted by Privateer383

Same list as previously posted by others, except I added the return tube o-ring lubricant as recommended in one of Henry Schmidt’s previous posts.

Outer Case Halves: Threebond 1104 (now 1184)

Bearing Saddle Surfaces: Loctite 574

#8 Bearing (balancer end) O-Ring: Threebond 1211 (now 1215)

Case Thru Bolts: Dow Corning 111 on Green Viton O-Rings

Flywheel Seal: DRY

Balancer Seal: DRY

Intermediate Shaft Cover to Case: ThreeBond 1211 (now 1215)

Oil Breather Cover to Case: ThreeBond 1211 (now 1215)

Cylinders to Case: Curil K-2 or ThreeBond 1211 (now 1215)

Cam Towers to Cylinder Heads: Threebond 1104 (now 1184)

Cam Chain Housings to Case: Threebond 1104 (now 1184)

Cam Chain Housings to Cam Towers: Threebond 1104 (now 1184)

Cam Chain Housing Cover to Cam Chain Housing: Threebond 1104 (now 1184)

Gaskets: Thin coat of Loctite 574

Oil return tube O-rings: Dow 55 o-ring lubricant (alternate: Dow 111).

Sorry to be a total PITA - with the border closed we can't get Threebond in Canada as it was recalled due to language on the packaging.

I've found an alternative to Threebond 1184 which is Aisin AB1184A. MSDS sheet says its made by Threebond, so should be good there.

Question is, for the areas that call for 1211 or 1215, is 1207 or 1281 a viable alternative, or do I just use the Curil T that I already have? Both the 1207 and 1281 are readily available as they are the Aisin brand manufactured by Threebond.

[Focker]

Looks like 1207 might work, except that its tack free in 3 minutes vs. 40 for the 1211. 1215 has a 20 minute tack free time.

The other difference is that the 1211 and 1215 are Oxime solvent, 1207 is Acetone.

First preference would be to use the exact products recommended, but as I mentioned, Threebond is currently unavailable in Canada, so need to look for the rebranded equivalents.

[horizontallyopp]

Originally Posted by Privateer383

Cam Chain Housings to Cam Towers: Threebond 1104 (now 1184)

A clarification question if anyone can help me out - this refers to the camshaft flange and it's associated gasket (not the o-ring - as with all o-rings, Dow would be used). So in this diagram, Threebond 1104/1184 on part #14, both sides, where it interfaces with the cam tower and the camshaft flange (part #16)



Many thanks

[WERK I]

I've used a light coating of Curil-T on both sides. Keeps the gasket in place during assembly and prevents weeping during engine heat cycles.

[KTL]

The point of using the sealant on the paper gasket is not only to give it some additional sealing ability but also to give the gasket some wiggle room to settle in place as you’re physically assembling the parts. This paper gasket can sometimes get pinched as you’re pushing the cover plate (actually called a thrust plate because the end of the camshaft can push against it during engine operation) home into the chain housing. So you definitely want to look around/behind the chain housing after installation to make sure the gasket didn’t get pinched or folded upon screwing down the thrust plate.

People have also recommended other sealants on this paper gasket like Permatex copper spray, Curil T green goop, and the famous Loctite 574 orange goop. Whatever works. Just don’t use silicone sealant, PLEASE! Again, the purpose is additional protection against a leak. I don’t like anything too sticky because sticky makes it more likely for the gasket to get stuck in a bad position. You want the gasket to have a little bit of ability to settle into place. But of course you don’t want it to squish out of place either! I have personally encountered this leak on one of my engine projects and it’s a big disappointment to have. It’s a lot of work to correct the leak and therefore you absolutely want to avoid it happening

My opinion is the gasket is supposed to be fine without sealant. That’s the whole point of the gasket- to seal. The challenge here is that the “snout” on the end of the camshaft housing is not always fully flat. I have leveled the snout on several cam housings via a flat plate and wet sandpaper which has shown me some spots on the snout are very narrowly flat with the rest of the surface. Therein lies the problem and I feel the problem should be addressed at the sealing surface to ensure the best seal. Just my opinion and to each his own, as the saying goes

It’s very easy to level the snout surface. All you need is a good flat surface, some tape, some wet sanding paper (400 or 600 is fine, no need to make it super smooth) and a sharpie marker to color the snout for use as an indicator of your sanding progress. You’ll see right away how flat, or not, is the snout after just a few swipes of the snout across the paper.

[mikedsilva]

I'm having difficulty locating Curil T.

However, I see Curil T2 is commonly available.

Is Curil T2 replacing Curil T?

[mikedsilva]

https://youtu.be/n6jJkWGA21U

[winders]

Originally Posted by mikedsilva

I'm having difficulty locating Curil T.

However, I see Curil T2 is commonly available.

Is Curil T2 replacing Curil T?

https://www.kmotorshop.com/en/content/detail/160/new-composition-of-curil-compounds-from-elring-and-its-new-product-curil-t2

To quote:

"Its [sic] called CURIL T2 and this name replaces the old designation of Curil K2 and Curil T sealants."

[ruddster84]

I could have missed it, but any sealant recommended on the gaskets for the chain tensioner covers?

[WERK I]

A very light tacky coat of Curil-T works quite well. Just enough to make the gasket look shiny is all it takes.

[VFR750]

Originally Posted by WERK I

A very light tacky coat of Curil-T works quite well. Just enough to make the gasket look shiny is all it takes.

+1

This works really well. Coat both sides of the gasket.

I do this on all paper engine/transmission gaskets.

[thetorch]

Just another set of data points from my recent 3.2 to 3.4 rebuild. Grateful for all the good information on this thread and to no longer have any oil on my garage floor.

Sealants:
Case perimeter: Threebond 1184
Case webs: Loctite 574
Through bolt o-rings: Molykote + tiny amount of Hondabond 4 on washers
#8 Bearing: Threebond 1211
Cylinder base shims: Curil-T
Heads to cam towers: Threebond 1184
Oil breather gasket: Hondabond 4
Chain housing to heads: PFTE grease on o-Ring, Hondabond 4 on gasket
Chain cover to case gaskets: light Hondabond 4
Chain cover gaskets: dry
Oil return tube o-rings: Molykote
Int Shaft cover gasket: Hondabond 4 failed, switched to Loctite 574 with new gasket.
Rear Main seal: Installed dry outer edge, light PTFE grease on inner to prevent burning on initial startup.

Leaks and fixes (none of the leaks were enough to even cause a drop on the floor):

• Intermediate shaft cover gasket. Was leaking around one of the bolts. Pulled off, removed studs, reflattened, Henry recommended loctite 574, new gasket. This fixed it.
• Valve cover driver's side, torque to 10nm. Slight leak forward corner. Tried plain type, green with silicone bead (worse) and now black graphite type. Yes I tried increasing the torque. Didn't work. TBD
• Oil Cooler lower ring: green one (small drip), red one with PTFE silicone grease (no different, small drip), going to try green one with Curil-T. The first 2 I could tell they just were not thick enough to get a crush. This is maddening.
• Lower oil pressure relief valve bolt: wetness around the aluminum washer. New crush washer and re-torque. Same thing. Noticed the washer wasn't centering. 3rd time: measured new Porsche bolt to original bolt. New one was over 1mm smaller at the chamfer that seals and centers the crush washer. Damn. Hopefully fixed it.

(new on right)

[DRACO A5OG]

Outstanding, enjoy your New 3.4L, she will feel 700 lbs lighter :-)

[CBRacerX]

Thanks for the excellent update @thetorch

[Henry Schmidt]

Curil T and Curil T2 are different formulas. T2 is higher temperature and lower viscosity.
We still use the "T" because it seems to stay in place better and temperature resistance is more than adequate.

Many new products offered by manufactures as "new and improved" are in fact just environmentally compliant.
1104 was replaced because of lead content not performance enhancements. Curil "T" was replaced to eliminate "undesirable solvents".
I guess they could have kept it with a Millennial safety warning "not for human consumption". Maybe much like Tide pods.

[mikedsilva]

Originally Posted by Henry Schmidt

Curil T and Curil T2 are different formulas. T2 is higher temperature and lower viscosity.
We still use the "T" because it seems to stay in place better and temperature resistance is more than adequate.

I much prefer to use T, but seems impossible to find...

[Henry Schmidt]

Originally Posted by mikedsilva

I much prefer to use T, but seems impossible to find...

Try Amazon. Shipping may be an issue. Many of the products we prefer to use are not California EPA compliant.

https://www.amazon.com/Elring-non-hardening-temperature-resistant-sealing-compound/dp/B01N0X8M8G/ref=sr_1_1?crid=2K0ITTVX7SRX1&keywords=curil+t&qid=1667344977&qu=eyJxc2MiOiIwLjc5IiwicXNhIjoiMC40OCIsInFzcCI6IjA uNTEifQ%3D%3D&sprefix=%2Caps%2C198&sr=8-1

[mikedsilva]

Originally Posted by Henry Schmidt

Try Amazon. Shipping may be an issue. Many of the products we prefer to use are not California EPA compliant.

https://www.amazon.com/Elring-non-hardening-temperature-resistant-sealing-compound/dp/B01N0X8M8G/ref=sr_1_1?crid=2K0ITTVX7SRX1&keywords=curil+t&qid=1667344977&qu=eyJxc2MiOiIwLjc5IiwicXNhIjoiMC40OCIsInFzcCI6IjA uNTEifQ%3D%3D&sprefix=%2Caps%2C198&sr=8-1

Last year I placed an order with this person. https://www.ebay.com.au/itm/333016778926

item got stuck in post in poland.. she said she would refund... never did... too much time had passed and I was not eligible for refund.