Header to Head leaks

[tortuga]

My header gaskets keep blowing little leaks resulting in that annoying ticking...I have been using the remflex gaskets without success. This is not a quick or easy R&R and i'd like to get over to the other side of the problem. I do have solid motor mounts and doubled aft header brackets holding stock SPF headers and Gas-N side pipes.

Thinking about going the no gasket route? Any advice on what to use and how to do it would be greatly appreciated?

To do this right i am going to have to remove the while system in order to check header flange flatness (again) and get everything really clean. I have replaced gaskets in the past by just breaking the header loose and swinging the whole mess out of the way...

Thanks
Steve H

[mrmustang]

Originally Posted by tortuga

My header gaskets keep blowing little leaks resulting in that annoying ticking...I have been using the remflex gaskets without success. This is not a quick or easy R&R and i'd like to get over to the other side of the problem. I do have solid motor mounts and doubled aft header brackets holding stock SPF headers and Gas-N side pipes.

Thinking about going the no gasket route? Any advice on what to use and how to do it would be greatly appreciated?

To do this right i am going to have to remove the while system in order to check header flange flatness (again) and get everything really clean. I have replaced gaskets in the past by just breaking the header loose and swinging the whole mess out of the way...

Thanks
Steve H

Steve,


Have you thought about pulling the headers and having them milled flat for a tighter seal? Then a simple exhaust gasket, a decent set of header bolts with lock washers, and you are good to go.
It will make a good project for you on Friday while you wait for the snow (or ice in your case) to arrive.





Bill S.

[S1965C]

What Bill said. You shouldn’t have leaks using Remflex gaskets. Also, what fasteners are you using? I safety wire at the cylinder head and never have issues with loosening fasteners.

[tortuga]

Torqued to 25ft lb like the instructions say, none are loose. Gaskets compressed…They ALWAYS fail at the top too, and now that i think of it always between 3-4 0r 7-8…

[DanEC]

I have used red and copper high temp RTV to seal exhaust manifolds with good success but haven’t used it on headers. I use SCE copper gaskets on my ERA headers and also on a Hemi engine with factory manifolds. They have always worked very well for me and are reusable.

[DanEC]

What you can do to see if it’s a flange issue is clean the surfaces and with a big felt tip marker color them black, or apply a light coat of black paint. For a sanding block on an aluminum intake port surface I used a new, 24” aluminum level which was about 1-1/4” wide and dead straight as far as I could tell establish with my steel straightedges. I put a strip of 320 +/- self adhesive sandpaper on it and block sanded across the ports a few strokes to see what I was dealing with. That will pretty quickly tell you if you have a minor surface irregularity on the ports or a major one that may require surfacing. If it doesn’t look too bad you can probably switch to some 220 and with some work get them pretty flat - although blocking steel will obviously be a lot harder than an aluminum manifold surface. You might even carefully be able to address high spots with a side angle grinder, going slowly. It straightened out my intake mating surfaces up and allowed them to sit and seal up tight. Just a thought.

[bobcowan]

If you keeping blow quality gaskets at the same place, it's not the gasket's fault. That's a weak spot for some reason, and you need to figure it out. Look for a fault in the head surface, or the header flange.

Since it's always at the top, consider that the bolts are not crushing the gaskets well. Put a washer on the header bolts and torque again.

[mrmustang]

Originally Posted by tortuga

Torqued to 25ft lb like the instructions say, none are loose. Gaskets compressed…They ALWAYS fail at the top too, and now that i think of it always between 3-4 0r 7-8…

Forgot to add to my initial post:



Look up "stage 8 header bolt kit" for your application. I've used them on most of my Cobras, and all of my race cars, without ever an issue.







Bill S.

[bobcowan]

If you keeping blow quality gaskets at the same place, it's not the gasket's fault. That's a weak spot for some reason, and you need to figure it out. Look for a fault in the head surface, or the header flange.

Since it's always at the top, consider that the bolts are not crushing the gaskets well. Put a washer on the header bolts and torque again.

[Jim Vander Wal]

I ran SCE #4736 copper gaskets for my AFR 225 heads. Also used studs, nuts and washers. No idea on torque, I just tightened 'em up. I used the 3" bolt spacing, wouldn't use the 2" spacing unless it was the only option.

I didn't have any real issues at the head but the header to sidepipe square flange and gaskets were problematic. Ultimately built soft copper gaskets for these flanges.

I'd guess that due to gravity pulling the header & exhaust system down the flanges will be tighter at the bottom and looser at the top. The bottom of the flange becomes the pivot point.

If you are going to pull the headers and have them machined flat you may need to remove more metal than expected. Header flanges and "flat" are often a problem.

Jim SPO 1855 & 2584

[eschaider]

Bill hit the nail squarely on the head. Your flanges are warped!

Mill them just enough to get them flat or replace them. Everything else is just going to prolong the pain and suffering. Of course, if you are into pain and suffering, that might be the preferred path to follow ...

BTW, if you don’t properly fix them, it is still possible to enjoy continued pain and suffering. All you need to do is mill them too thin, and you will be good to go for another round of pain and suffering.

Then of course, you could just go and buy a nice set of 3/8ths or half-inch (if you are a bad welder) flanges, put them on, and forget about all this crazy gasket stuff — but that wouldn’t be much fun now, would it? Moreover, what would you have to post about?

[bkozlow]

My first question is are you attaching the headers only to the engine or are you not wanting to break that great seal you have on the mufflers to the header connection whether slip on or gasket seal. Try one side, disconnect the side pipes and do the headers only. Many times the weight of the whole system causes the installation of the header flange to be at a SLIGHT ANGLE TO THE HEAD, usually the bottom of the header flange is in slightly and this off set is enough to put less pressure on the upper
edge of the flange causing a leak on the top of the flange. Take the extra time to make sure the flange is square to the head. I like using a coupe of studs to hold the header up while I start the header bolts and when the bolts are in place remove the studs and replace them with a bolt. I found this reduced greatly leakage problems. The remflex gaskets are suppose to allow for 1/16 inch out of flat which is a great amount. A straight edge on the flange should give you some idea where the problem is.

Bill K

[undy]

I was plagued with this with my headers and tried various gaskets to include Stage 8s. Nothing worked. I finally fixed it 100% with RTV ultra high temp silicon. 15 years later and not a hint of header leak noises.