header sealing

[bobcat68rs]

What is the best way to seal my headers? I have a set of stainless works for my camaro. The folks at SW said to use some high temp rtv? Is anyone else doing this? I have never heard of this by its self.

Thanks Robert

[70rs]

How about a set of exhaust gaskets?

I have never heard of using rtv either. Someone from SW said to use that alone?

[MarkM66]

Some really swear by using the high temp red rtv.

I've never used it, as it seems to always make a mess.

A good gasket has worked for me.

[GregWeld]

What is the best way to seal my headers? I have a set of stainless works for my camaro. The folks at SW said to use some high temp rtv? Is anyone else doing this? I have never heard of this by its self.

Thanks Robert

I normally prefer to use the aluminum framed gaskets (replaceable inserts) from Earls...

A link to the "style" I'm talking about:

http://www.jegs.com/i/Earl%26%23039%3Bs/361/29D03B/10002/-1


But, recently I used the high temp RTV (red) on my header to head and header to down pipe on my '32 Ford and it works flawlessly so far. I think that the key here is flat perfect (CLEAN!) surfaces. Any flaws in the mating surfaces would need a gasket to take up the defects. It wasn't as messy --- BUT I have open hood sides so working on them is super easy... otherwise it would have been "rtv all over everything".

I've found over the years the number one issue with header leaks is the LACK OF going back to snug the blots after some heat cycles if you don't use locking bolts.

I personally prefer the PERCYS Split-Lock bolts. I've never had one come loose after the first tightening.... and MOST IMPORTANT... the shoulder on the bolt is far smaller than the ARP versions which can cause interference on some headers... and they use a smaller head so I can actually get a wrench on them! Tighten them up - and use a hex head to lock - no additional hardware (ugly) like the Stage 8 etc. But it's the shoulder and head size that make them the killer bolt for SBC and BBC IMHO.

[bobcat68rs]

The gasket was the obvious choice, I also had never heard of just the rtv.
The motor is a ls-2 so the heads have a smooth surface as do the headers.
Yes I was told this by the tech guy at SW, he did suggest using grade 5 or 8 bolts. But i think they wouldn't look very good, also be a pain to work with.
The mess was another concern i had. Do you think it would work the same if you let it skin over abit before the header was bolted up? Or do you think it would kill it's abilty to seal?

[ccracin]

I have talked with several engine builders that recommend the red rtv. One even said with 3/8 flanges milled flat, no gasket at all is required. We will use a bit of RTV.

Let me spew some info I have gained on header gaskets. As Greg said, re-torquing after multiple heat cycles is essential. Is is also still required when using locking hardware of any type. The locking hardware only keeps you from loosing the bolt. When using any gasket that can "crush" or get thinned under pressure you will still loose the effective seal at some point and reduce the gaskets chance of not burning by and creating a large leak. When the gasket thins permanently the bolt with locking hardware will stay in, but is no longer torqued the same as when you put it in. The clamp load is lost. This is one of the benefits of the rtv. When you torque the header, most of the rtv is displaced. you will have metal to metal contact in some areas and the rtv only remains to fill the voids. As Greg also said CLEAN, FLAT, UNDAMAGED surfaces are best in all cases. By the way, this thought process applies to most compressible gaskets and yes, you can over torque compressible gaskets. That's another talk. Hope this helps. Good Luck. Spewing finished! :cheers:

[70rs]

Thanks for the great info Greg & Chad. I had no idea about using sealer instead of gaskets. It makes sense, I just never heard of it. I wish I had a long time ago.

[bobcat68rs]

One other thing that the SW tech suggested was to stay away from stainless steel bolts. He said there's a greater chance of striping the threads out of the aluminum heads. If I went with percy's black oxide bolts would I still have this concern?

Thanks Robert

[ccracin]

Stainless fasteners should always be used with anti-seize compound. Copper based is usually preferred in high heat applications. You have to reduce the torque when putting any bolt into tapped aluminum threads. Your head manufacturer should give you the recommended torque. This is also another good reason to use a locking fastener. Typically when putting a bolt into tapped aluminum holes you cannot achieve the proper bolt stretch to create a proper bolted joint due to the reduced torque. When you add a compressible gasket to the equation, it is even worse. Therefore use a locking fastener in all cases. I would also use anti-seize in aluminum heads regardless of the fastener material. If the carbon steel fasteners start to rust due to the heat, the anti-seize will help. :cheers:

[Coursey]

Sanderson recommends that you install an 1/8" bead of rtv to the header and let it setup over night. Then install to the head.