Worst-case Header Sealing Scenario? What to do?

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Worst-case Header Sealing Scenario? What to do?

Post by NewbVetteGuy »

I'm trying to get a set of 1 5/8" FlowTech 31106FLT headers, which originally came with O-rings, to fit and seal on a set of Profiler 195cc heads, and they're a match made in hell so I could use some advice.

On the head side:
I've read two of the ST threads on these heads' exhaust ports trying to divine a gasket that will get me close:
viewtopic.php?f=1&t=49461&start=75
viewtopic.php?f=1&t=56283&start=30

There's mention that the FelPro 1406 gasket for the Brodix Track1 raised port heads gets close, then there's a generic mention of a Summit Racing and a Jegs gasket that supposedly work (no link, no PN), but from what I can gather they work because they're significantly oversized... That's going to be an issue with the O-ringed header (see below).

There a few other mentions of using a gasket for the GM FastBurn heads; GM recommends Felpro 1470, which says it's an LT1 gasket and I thought they had different bolt patterns.

Header-side challenges:
These @#$@#$ "Holley" flowtechs came with O-rings that have been lost to history, that means the flange isn't actually FLAT. Holley got the O-rings from a supplier of a supplier and can't even tell me where to buy new ones, nor can they sell replacement O-rings...

-To make the headers REMOTELY work with the Profilers, I had to pull out the die grinder and carbide and go to town on the headers AND elongate / slot the bolt holes. -That gives a VERY small width ring around each port.

---I'll take a post a picture later showing what the flange looks like all done.


What is the gasket MATERIAL that's going to give me the best chance of these things ever sealing? -I am also likely going to have to be able to cut and modify the gasket so steel core options seem to work against me here.

Copper coat the crap out of whatever gasket I use? RTV?
Get the surface of the header flange ground flat?
-Sacrificially burn the FlowTech header in a pyre, put it on YouTube, give it a clickbait title, and use ad revenue to buy a header with a flat flange and none of this O-ring BS, port that one, enlongate the bolt holes in that one and then weld it up?!?!

Someone @ Profiler should be drug out in the street and tarred and feathered for not just centering the D@#$@# bolt holes!
Some @ Holley canned for releasing an O-ringed header and not having replacement O-rings for sale!

I've got a stage 8 bolt set so I have one thing going for me...

Header:
https://www.holley.com/products/exhaust ... s/31106FLT

Adam
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Re: Worst-case Header Sealing Scenario? What to do?

Post by Kevin Johnson »

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Re: Worst-case Header Sealing Scenario? What to do?

Post by Krooser »

Most of the dirt cars I see run that high temp silver RTV without a gasket.
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Re: Worst-case Header Sealing Scenario? What to do?

Post by dannobee »

Do you have a pic of the o-ring and or groove? Can you surmise what type of material the original o-ring is made of? Even a wildass guess would help.

No gaskets worked for me for a bunch of years. Make sure the flange is nice and flat and bolt 'em up.
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Re: Worst-case Header Sealing Scenario? What to do?

Post by NewbVetteGuy »

dannobee wrote: Wed May 06, 2020 6:31 pm Do you have a pic of the o-ring and or groove? Can you surmise what type of material the original o-ring is made of? Even a wildass guess would help.

No gaskets worked for me for a bunch of years. Make sure the flange is nice and flat and bolt 'em up.

I don't have any of the o-rings and it's not a groove. I seriously WISH it were a groove.
Going to take a pic.


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Re: Worst-case Header Sealing Scenario? What to do?

Post by Kevin Johnson »

https://www.holley.com/products/gaskets/header_gaskets/parts/99150FLT wrote:HEADER GASKETS - ALUMINUM-LAYERED - 262-400 CHEVROLET SMALL BLOCK GEN I 1955-91
Flowtech, Dead Soft Layered Aluminum Material, Round Ports

PART# 99150FLT

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Re: Worst-case Header Sealing Scenario? What to do?

Post by BOOT »

If I understand the question right I don't think gaskets are an ideal fix, you'd have to stack up several to equal the compressed difference for the raised sealing edge and it's gonna be alot of trial and error to see what holds up as it looks like that header doesn't have much flange material to hold them. That could get expensive.

Might be best to weld around the 0-ring(raised sealing metal edge) and resurface flat. If you do it yourself, I'd cut the flange to separate the ends tubes cause your prob not gonna get them all at the exact same angle if you use something like a belt sander.

Or you could cut off the old flange and get a flat thicker one to weld on.

Being Ceramic coated I bet you wanna go the gasket route. Summit has a better pic so people can see what you mean by 0-ring(raised sealing edge) https://www.summitracing.com/parts/big-31106flt It prob would of been best to get header with larger tubes/o-ring. Replacement o-rings prob wouldn't help if the material you removed to match was just in the port and not clamping the gasket.
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Re: Worst-case Header Sealing Scenario? What to do?

Post by NewbVetteGuy »

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Re: Worst-case Header Sealing Scenario? What to do?

Post by dannobee »

Grind all of that nonsense off and run them right up against the head. No gasket, metal to metal. Use Krooser's RTV if it makes you feel better.
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Re: Worst-case Header Sealing Scenario? What to do?

Post by rfoll »

You might try the Remflex gaskets. They are thick graphite with a non metallic mesh. They will not tolerate over tightening, but will seal almost anything warped or whatever.http://catalog.remflex.com/
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Re: Worst-case Header Sealing Scenario? What to do?

Post by pcnsd »

NewbVetteGuy wrote: Wed May 06, 2020 8:36 pm Pictures attached
So that is what $400 buys these days? Send them back and ask for a set that isn't F'd up or get your money back and look elsewhere for options.
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Re: Worst-case Header Sealing Scenario? What to do?

Post by Jeff Lee »

Nice bead of “Right Stuff”, let it sit about 5 minutes and slap them on. Will never leak. About $15 for a small tube.
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Re: Worst-case Header Sealing Scenario? What to do?

Post by Ericnova »

I don't see anything odd with that flange that requires some oddball gasket ???.

Looks just like every Hooker, Hedman, Blackjack, Cyclone, Dynomax, Schoenfeld, Patriot, Thrush, Summit, Jeg's, etc header flange for the last 45+years, they all used that "push the tube through the hole, weld all around the end of the tube to the flange, and grind the weld to a flat bead to form a raised sealing bead to press against the gasket" type of deal.

The original FlowTech gaskets were an aluminum frame that held individual sections of a Remflex type perforated graphite gasket at each port opening from what I remember....those inserts looked a lot like the manifold gaskets that come is a standard engine full rebuild gasket set.

The Remflex gaskets as has been suggested, or do like most racers do, use a bead of high temp RTV around each tube lip and bolt them straight to the head with no gasket at all, are going to be your two best choices.
Remflex, for "welded bead header flanges":
http://catalog.remflex.com/CHEVROLET_GM ... p/2031.htm

Try to grind those bead welds down flat to the flange and the tubes will all come loose from the flange, because they ain't welded on the frontside at all.
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Re: Worst-case Header Sealing Scenario? What to do?

Post by 77cruiser »

This is what you need to fix it right. http://www.spdexhaust.com/pdfs/HeadFlanges/SBC_OEM.pdf The bottom set.
I don't think I'd buy another set of Profilers for that reason, unless I wanted to build another set of headers.
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Re: Worst-case Header Sealing Scenario? What to do?

Post by NewbVetteGuy »

rfoll wrote: Wed May 06, 2020 9:44 pm You might try the Remflex gaskets. They are thick graphite with a non metallic mesh. They will not tolerate over tightening, but will seal almost anything warped or whatever.http://catalog.remflex.com/
If I go that route, I will need to cut the gasket and the holes to match my raised ports. What can I use to cut this reflex stuff? Something significantly more intense than an exacto knife, I'm guessing.


Adam
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