The Complete Engine Sealant Thread...

[Bluetarga78]

I wasn’t sure if my question pertaining to using silk thread as a gasket material embedded in the loctite 574 was relevant in this thread so I started a new thread. Also, not trying to steal any thoughts here, just a different approach I was asking for advice on.

[Turbo_pro]

Originally Posted by Bluetarga78

I wasn’t sure if my question pertaining to using silk thread as a gasket material embedded in the loctite 574 was relevant in this thread so I started a new thread. Also, not trying to steal any thoughts here, just a different approach I was asking for advice on.

My only concern with using silk thread is deterioration. The 574 will harden but the thread will not. The thread could affect the clamping force of the bolts reducing predetermined force required to prevent case shuffle. As the aluminum expands and contracts with heat, the thread can compress. If this compression allows for excess movement, the 574 can crack. All speculation but that's my guess.
I am not an engineer so take it for what it's worth $.02.

[dannobee]

Literally billions and billions of engines have been built from all manufacturers around the globe using some version or copy of ThreeBond grey RTV. It's been proven over decades of use with very low incidents of warranty claims. No need to try to reinvent the wheel or use materials and procedures from the middle of the last century (aircraft).

Use the tried and true materials and procedures outlined in this thread. Especially when considering the labor involved in repairing a leak at the case halves on one of these engines.

[85RedCarrera]

The primary issue that I have with some silicone products on aluminum is when it’s time to remove it- so I don’t use some products anywhere I might be going back into anytime in the ‘foreseeable’ future. Most Silicone on steel is no biggie- just get a brass brush and it’ll all come off.

Dirko required Digesil (best product ever for removing all traces of silicone) to Get it completely off the aluminum. Acetone was useless.

On my Ducatis, the Threebond type products are easy to remove- and then Acetone removes every trace of it. Not so with the Dirko- extremely tenacious stuff…. And I expect that that is desirable, as the bead after squeeze out inside the case seems firm and well adhered, so that it won’t sprout legs and walk through the engine.

I must admit though, getting the squeeze out with Dirko exactly where you want it to be, depends on the flange width and the amount applied, and I am used to using the Threebond type products on narrow flanges, and you don’t need much product at all in that scenario.

The first Porsche case I sealed with Dirko could have used a bit more than I applied, as I was just a hair less than the squeeze out that I wanted. It’s cleaned up now and I’ll be sealing it again soon. Next time I use Dirko I expect I’ll get it just right. Using New products sometimes require a practice session..!

[00 Scrub]

What are people using to seal the crankcase vents (the opening covered in green tape) on GT3 blocks? I was planning to use Hylomar M. Any reason not to and use a silicone instead?

[CBRacerX]

Originally Posted by JoeMag

I think you're always going to get some squeeze out. You're probably squeezing out 80% of what was put on the surface. Clearly not the experience of Henry... I've rebuild my motor few times, put threebond 1184 on one case half (basically completely cover the one surface). Some may run down inside of case (maybe I applied too much). These few streaks (not large rivers) have stuck to inside of case (if case is very clean, it should, right? the surface is quite rough so lots to bond to). It takes work to get them off when you split case again.

Unplanned squeeze out test https://forums.pelicanparts.com/911-engine-rebuilding-forum/302345-sealing-case-experiment-so-you-dont-have.html

[Brookieslayer]

Originally Posted by Henry Schmidt

Over the last 18 months, we have been doing some in-house testing of hi temp Dirko Grey.
So far the results are good.
Elasticity, elongated breakaway and chemical resistance is impressive.
The shear strength is better than ThreeBond 1184 and the tensile strength is comparable.
Pressure @ .080" gap is better than ThreeBond or Loctite 574.

Good Evening,

Henry are you replacing 1184 with the Dirko Grey in your kit now? Or is the 1184 still the kit staple?

Thanks for your contributions to the community.

[Henry Schmidt]

Originally Posted by Brookieslayer

Good Evening,

Henry are you replacing 1184 with the Dirko Grey in your kit now? Or is the 1184 still the kit staple?

Thanks for your contributions to the community.

What we use in-house is Dirko HT but for those customers committed to the TB 1184, my kit can ship with either product. Customer choice.

[Brookieslayer]

Originally Posted by Henry Schmidt

What we use in-house is Dirko HT but for those customers committed to the TB 1184, my kit can ship with either product. Customer choice.

Thanks Henry. Appreciate the information.

[Henry Schmidt]

I got an email this morning and here's how it went:

Hello Henry,
Sorry to bother you but I just wanted to see if your preferred sealant used between the heads and cam housing is still Threebond 1184 or now the Durko HT?
Thank you for your help and Happy Holidays,

Good morning XXXXXXX
No bother at all.
Either product is good for this application.
We used ThreeBond for 2 decades+ with good results.
At the prompting of a sales rep we decided to do some comparative testing between
TB 1184, Dirko Grey and Dirko Grey HT. Our test results were very close.
Break away, squeeze out, rotational flexibility and chemical resistance were the test criteria.
The clear winner was Dirko HT based primarily on the break away and high heat range resistance
In house we use Dirko HT but we offer the choice of HT or TB in our sealant kit.

Cheers
Henry

[OsoMoore]

Just wanted to note that I used the Supertec Sealant Kit on my rebuild these past few months. So far (20 min valve break-in) no leaks or issues.

I followed Wayne's book for the rebuild, except wherever sealants and such were concerned, where I used the instructions in the kit. For the gaskets, I laid down a bead and then smeared it with a gloved finger. Verified I had a small amount of squeeze-out along the entire edge.

Every mating surface was carefully cleaned, largely with a "plastic razor blade" tool and many blades, along with brake cleaner and 99% isopropyl alcohol.

With winter snow setting in, I'm not sure when I'll be able to do the full break-in on the road. I'll update with status later.

[Henry Schmidt]

Congratulations on your first start-up.
No leaks is a great start.

Originally Posted by OsoMoore

Just wanted to note that I used the Supertec Sealant Kit on my rebuild these past few months. So far (20 min valve break-in) no leaks or issues.

I followed Wayne's book for the rebuild, except wherever sealants and such were concerned, where I used the instructions in the kit. For the gaskets, I laid down a bead and then smeared it with a gloved finger. Verified I had a small amount of squeeze-out along the entire edge.

Every mating surface was carefully cleaned, largely with a "plastic razor blade" tool and many blades, along with brake cleaner and 99% isopropyl alcohol.

With winter snow setting in, I'm not sure when I'll be able to do the full break-in on the road. I'll update with status later.

[Ovis]

I as well used the Supertec on the motor build I completed this past year. I have about 300 miles on my break in and so far no leaks. Very pleasantly surprised and I hope the motor stays that way. Henry also built me a set of heads, the motor is a screamer! Now if spring would just hurry up and get here.

[Henry Schmidt]

Originally Posted by Ovis

Now if spring would just hurry up and get here.

Snow chains ?

[Ovis]

Originally Posted by Henry Schmidt

Snow chains ?

Not a bad idea! My dad did drive the car in the winter when I was a kid.

Henry quick (and probably dumb) question. After a new motor build, is it a requirement to re-torque/check the head studs after a certain amount of miles? I used your head studs for my build.

Also, at how many miles do you do a valve adjustment?

Thanks Henry!

[Henry Schmidt]

Originally Posted by Ovis

Not a bad idea! My dad did drive the car in the winter when I was a kid.

Henry quick (and probably dumb) question. After a new motor build, is it a requirement to re-torque/check the head studs after a certain amount of miles? I used your head studs for my build.

Also, at how many miles do you do a valve adjustment?

Thanks Henry!

You should not need to re-torque our head studs. If there is an issue with cylinder stack (IE: inconsistent machine work) you may find yourself with an inconsistent torque after a few heat cycles but generally, our head studs are a one and done proposition.
I like to do a thorough one follow up service at 500 miles and then a regular service with a valve adjustment every 10K. Oil service every 3K unless the car sits then every 18 months.