Header Leak "Fixed"...yes, I did a search

[Chief Master Sergeant]

I'm having no luck sealing these damn headers and need some advice. I'm using WH shorty headers, Percy Gaskets, and Stage 8 Bolts. I initially had a leak at one driver's side port and we pulled it, put a straight edge on it. It showed a slight gap at one of the ports, so WH replaced it. Now, I'm getting the same type leak at all four ports. The gaskets didn't mention orientation, so I looked on line. Their website said the flat side of the gasket should face the header. Is that correct? I checked the head with a straight edge and it appears to be straight. Any help would be greatly appreciated.

 

[Labbster]

CRAP! Sorry to hear this. I just installed same thing but haven't fired it up yet. Will be watching the thread!

 

[pcf_mark]

If it is not flat it certainly will have a challenge sealing. If you over tighten the bolts you can pull the header out of shape. I usually tighten them "tight" but not crazy. Run the engine and get it hot then let is cool and tighten them again.

Do you have an exhaust hanger close to the flange? If the only hanger is way at the back then you are hanging the exhaust off the header flange and this may put too much force on the header flange.

 

[Mherriford]

I am looking at replacing manifold gaskets this next week too. My small leak seems to have gotten much bigger after last weekends wheeling trip. Has anyone ever tried the mr gasket dead soft aluminum gaskets?

Hopefully you get your situation fixed soon, I know when I install new exhaust gaskets I have to tighten the bolts down after each heat and cool cycle, probably 4 or 5 times total.

 

[Broncobowsher]

Are the bolts now loose? Yes I know stage 8 don't come loose, but the gasket can compress.

Another overlooked problem is the exhaust itself. Is it properly supported? Most are not. Where are your exhaust hangers? If you look at small block fords with factory headers (Mustangs and Explorers come to mind) the first hanger is about the transmission crossmember, and actually attached to the transmission and not the body/frame. This keeps the exhaust from bouncing and rocking, distorting the header to head seal. If lucky it is only the gasket. If it rocks too much it can pull the flange in at the bolt holes (it will look like you overtightened the flange bolts if you straight edge it).

 

[67RT]

I am looking at replacing manifold gaskets this next week too. My small leak seems to have gotten much bigger after last weekends wheeling trip. Has anyone ever tried the mr gasket dead soft aluminum gaskets?

Hopefully you get your situation fixed soon, I know when I install new exhaust gaskets I have to tighten the bolts down after each heat and cool cycle, probably 4 or 5 times total.

I used Remflex gaskets on my 440. They are expensive but worth every penny, especially since it takes about a day to do the drivers side on my mopar as they crammed this giant motor into it. I had to drop motor mounts, jack engine, remove collector, etc...
Anyway, Remflex!

 

[Chief Master Sergeant]

I used Remflex gaskets on my 440. They are expensive but worth every penny, especially since it takes about a day to do the drivers side on my mopar as they crammed this giant motor into it. I had to drop motor mounts, jack engine, remove collector, etc...
Anyway, Remflex!

Looking at the Remflex online now. Not seeing exactly which ones work for our application. Anyone use them on a 302 and know the part number?

 

[67RT]

Ii will check. Not sure if they do headers. U looking for headers or exhaust manifold?

 

[67RT]

http://www.amazon.com/gp/aw/d/B00B2...&dpID=41nm6izUsLL&ref=plSrch&pi=AC_SY200_QL40

Install shiny side out toward header. Works for either header or manifold..

 

[blubuckaroo]

Locking header bolts won't eliminate the leak. Stage 8 bolts just make it harder to retighten, and are just a pain! That's a problem because the leak will happen even with the bolt locked down. The gasket compresses and needs retightening a couple times for the first month. Mine have been there for six years now without any retightnening.
I just use the white Hooker gaskets, and retighten them every week for a month. At the end they don't take much tightening. I use these Nord lock washers on the bolts.
http://www.nord-lock.com/nord-lock/wedge-locking/washers/introduction/

 

[miikee73]

Is there a chance you are bottoming the bolts out? I would think stage 8 would send the right length bolt ,but a few threads could make a difference. Run one in the bare head to be sure . Just as everyone has said ,retighten several times,don't wait till you hear the tic,by that time it's probably too late. I also used anti seize ...

 

[Chief Master Sergeant]

All good suggestions. I'll let you know

 

[jim3326]

His exhaust is supported correctly, 2 into1, 1st hanger is at the transfer shifter in front of muffler. He had to put extreme upward pressure on the driver side to bolt up the collector so we cut the tube to relieve the pressure so that should be ok now. I'm hoping the re-tightening process will do the trick.

Jim W.

 

[Chief Master Sergeant]

I heated it up and retightened it. When I cranked it up, I used a piece of hose and listened at each port. It appears the leak is coming from across the entire bottom of the header gasket. I'll keep trying this heat and tighten routine until the new header gasket comes in.

 

[Bronco_69]

I know it sounds redneck but after years of racing all I use is high temp copper RTV. never ever have a leak.

most all drag racers that I know of also use rtv only.

 

[m_m70]

Installed mine with the "smooth" side toward the head and have had no issues. I have re-used these as well so you may want to try to turn them around instead of buying a new set to see if that helps.

From there site:
"Installation of the gaskets is critical to the life of the Seal-4-Good gasket. On Percy's Header Flange gaskets make sure you install the gaskets with the smooth side facing the Head. All old gasket material must be removed from the flange so as not to create a "high" spot for hot gases to flow thru. Second, file down any raised areas on the flange again limiting the risks of a leak. Third, do not over tighten the bolts this may cause the flanges to warp causing an incurable leak. And finally be sure to retighten the bolts after a few hours of use to prevent leaking."

Good luck!
Mike

 

[Chief Master Sergeant]

Installed mine with the "smooth" side toward the head and have had no issues. I have re-used these as well so you may want to try to turn them around instead of buying a new set to see if that helps.

From there site:
"Installation of the gaskets is critical to the life of the Seal-4-Good gasket. On Percy's Header Flange gaskets make sure you install the gaskets with the smooth side facing the Head. All old gasket material must be removed from the flange so as not to create a "high" spot for hot gases to flow thru. Second, file down any raised areas on the flange again limiting the risks of a leak. Third, do not over tighten the bolts this may cause the flanges to warp causing an incurable leak. And finally be sure to retighten the bolts after a few hours of use to prevent leaking."

Good luck!
Mike

Yeah, I've tried the gaskets both ways. Had an extra set, so it was a new gasket each time. The interference idea is worth looking into, as I can't explain why they would be leaking across the entire length of the header at the bottom. I've gotten them pretty snug without having to bow up on them. Frustrating!

 

[welndmn]

The first thing I do on a difficult to seal rig, is cut the header flange apart so each port is separate.
It been something hot rodders have been doing for years.

 

[blubuckaroo]

Are you disconnecting the collector flange before installing the new gasket? If you leave them connected, the header could be twisted in a bind.

 

[m_m70]

If you have an extra set you could try doubling them up. I have read in other forums that this has worked when the header flange wasn't perfectly flat/straight.
Definitely want to disconnect the flange from the header as well to not have the pressure on the header when installing.
I have used the thick aluminum Remflex gaskets in the past with good results with headers that had issues. With the Remflex, you will need to re-tighten half a dozen times as that gasket really compresses but it does seal well.