Liquid Gasket maker high temp

[BAsque1]

I am re-installing the headers to my block and someone suggested a liquid gasket maker material that after curing 24 hrs can withstand up to 600 F any one has any experience on this product. I believe it is manufactured by Permatex. I believe this is the product Permatex® High-Temp Red RTV Silicone Gasket
Tks for the input
Happy Easter

[Hotfingrs]

You can use that on the collector end, but not at the head end.

[BAsque1]

That's what I thought but the source who told me this is a reputable header maker.

[vector1]

i've used the red, black, whatever rtv i had on the header flange, no problems. just kind of messy if you are not careful. use it on the bolt threads to keep them from backing out. this last time i used a regular gasket, so see how that goes, may have to go back to the rtv.

[scottj]

same here... high temp not needed... I use clear 100% silicone instead of gaskets and also as a thread locker. The only thing I like better is the oem MLS gasket on the new motor... still use a little silicone on the threads.

[jwd]

I've been using Permatex hi-temp RTV on header flanges for many, many years. Never had a single failure. That's what it's made for.

[bobcowan]

Permatex high temp Copper silicone sealant. That's all I use on my headers. I tear my engine down every two years (sometimes more often). and that seal always looks good, with no hint of a failure.

I also make sure to get some on the threads of the bolts. They never come loose. Never.



The local speed shop I use is owned by a guy who's been drag racing for decades. He uses clear silicone bathtub caulking. He likes it because it works, and can't be seen. I tried it, and it worked just fine. I took the headers off after a while for another reason, and I didn't like the way it looked. I had some doubts about it lasting a long time. I went back to the red stuff.

[ERA Chas]

BOB-Do you let it cure into a 'gasket' before joining?

[BAsque1]

Originally Posted by ERA Chas

BOB-Do you let it cure into a 'gasket' before joining?

That is my question also, or do you install the header with the Permatex still wet?

[vector1]

install it wet, so it sets up and makes a gasket in the intended position.

[carmine]

Install wet

Snug header bolts lightly so header in place

Let cure for 24 hours

Tighten to proper torque

[CHANMADD]

That picture with all that red goop is frightening... When that dries you are going to have so much crap obstructing the air flow , that any porti.g or polishing or port matching will ne negated. I have used black high temp for years, but on my last couple of builds I have only used the dry gaskets from the factory and they also work perfectly.

[bobcowan]

I apply the sealer, and then install the header. I torque to specs during the initial install, just like you would a gasket. They never fail.

[Barry_R]

The red silicone will work. If it matter to you, it will also sometimes squish out into the port and block off some of the port opening you may have worked to optimize. I usually use a Fel-Pro or other reinforced header gasket and add a thin film of the silicone instead of running the big blob.

[lovehamr]

Originally Posted by scottj

The only thing I like better is the oem MLS gasket on the new motor....

That's what I use now. The headers built for most of our cars are quite robust and inflexible and this would seem to be the reason the thin MLS gaskets hold up so well. I’ve tried various other “header gaskets” only to have them each fail inside 6 months. The last time I had the headers out, the only thing I had on the shelf was the OEM type MLS gaskets so I put them in. Viola’ no more leaks and 2k miles later the bolts (which were installed with anti-seize) are still tight.