spitfire header gasket question

-
65TerrorCuda

65TerrorCuda

Well-Known Member
Joined
Jul 26, 2009
Messages
1,261
Reaction score
839
Location
Albuquerque, New Mexico
I'm looking to replace the original thick as hell white paper(asbestos? fiberglass?) gaskets that shipped with the old Harold Johnson headers. Anybody know? I wish I'd read the name printed on them before throwing them out. They didn't leak and survived multiple teardowns over the years. They were the small rectangular port 273/318 style.

This is to fit spitfires onto speedmaster heads.

Any info appreciated!!
 
65TerrorCuda said:
I'm looking to replace the original thick as hell white paper(asbestos? fiberglass?) gaskets that shipped with the old Harold Johnson headers. Anybody know? I wish I'd read the name printed on them before throwing them out. They didn't leak and survived multiple teardowns over the years. They were the small rectangular port 273/318 style.

This is to fit spitfires onto speedmaster heads.

Any info appreciated!!
Click to expand...

If you don’t find out what you asked, Remflex gaskets are the best you can get for hedders.

Here’s some reviews on them, and I agree with the 5 star rating 100%.
 
TrailBeast said:
If you don’t find out what you asked, Remflex gaskets are the best you can get for hedders.

Here’s some reviews on them, and I agree with the 5 star rating 100%.
[/URL]
Click to expand...
I've heard nothing but good about remflex. They're certainly in the running. Meantime I've got these ready to be installed:
Mr. Gasket 358 Mr. Gasket Performance Header Gaskets

They are really old stock but look like they'd work. About 1/2 the thickness of the originals
 
If you took the time to file the flanges straight, take off the hills, fill the valleys of those old headers, you can use cheap old Mr Gaskets, and likely never have a gskt leak again .
 
The only drawback to Remflex is they normally tear up on disassembly. But I cannot agree more strongly with their 5 star rating. They are that good. That's what I used on my slant 6. They flat seal.
 
Felpro 1413 were the only gaskets that survived my nitrous injected 71 Dart back in the day. I can't say anything about remflex because the Felpro worked.
 
Let me remind you of an old trick that may or may not work for you. Soak the cheap header gaskets in a tray of water overnight. Thay will fluff up a little and when you tighten down the header they will squish and fill in any imperfections.
It's worth a try and if it works you can save some money.
 
66Valiant528 said:
Let me remind you of an old trick that may or may not work for you. Soak the cheap header gaskets in a tray of water overnight. Thay will fluff up a little and when you tighten down the header they will squish and fill in any imperfections.
It's worth a try and if it works you can save some money.
Click to expand...
All that's ever done for me was make the gaskets fall apart. lol
 
RustyRatRod said:
The only drawback to Remflex is they normally tear up on disassembly. But I cannot agree more strongly with their 5 star rating. They are that good. That's what I used on my slant 6. They flat seal.
Click to expand...
I was able to use the same set on two different motors without them coming apart.
On my car the #8 cylinder tube is not attached to the flange, and when I was shifting the exhaust a bit that separate tube tore the gasket (kinda smeared it).
I had to buy a whole new set of Remflex just for that one end piece. (Ouch) :D

IMG_4505.jpeg
 
A trick or method I use whenever I unbolt my headers for whatever reason or remove the exhaust for installing extensions (at strip) with the Remflex gaskets is to just loosen the bolts a smidge, remove a few so the headers can move a little more and then rap the headers at the flanges with a dead blow hammer, and grab them at the collectors, lifting up and pushing down on the headers to crack the seal vs pulling the header away from the head. This “In My Experience” prevents any tearing, delaminating or r crumbling of the gaskets. So far so good. Can’t count the times I’ve done this and they still are intact.
Your results may vary, it could be any number of things why damage happens. The two applications with the sets I have there has been no tearing or delaminating of the gaskets with removal, header or reducers. Maybe I’m just lucky.
 
Tried some old copper gaskets, they don't fit anything I own. Not sure what they fit.
These guys:
Mr. Gasket 7166MRG Mr. Gasket Copper Seal Header Gaskets

Not looking to tig up n grind the header flange to make stuff work unless it comes to that

Those mr gasket 358's are acrylic fiber. That sure doesn't sound hi temp to me!



Great advice again guys, I really do appreciate it! Making me think here. I can return the almost $30 Mr. Gaskets and get something else
 
I started my apprenticeship, and all I did for 5 yrs, was oil changes, brakes, 2 to 4 bbl changes, 3/4 race cams, 4:11 gears, and headers, headers headers .
After mosta the first 6 sets leaked like hell, customers bitches, my mentor showed me how to fair the header flange by welding up the valleys and filing down the hills of flange weld.
Back then the assembly welding including flange was by hand, and not planed true flat, like these days.but even now, they are not always true !
I never let a job leave with a leak, if it started to leak later, I removed and re-draw filed the weld on it, no charge.
I have checked true, and draw filed every set since, dozens and dozens of sets, all makes .
Need a 1/8 inch clearance at a pipe, file the flange !
I always use the gaskets sets supplied or plain Mr Gaskets on every job, never even seen a Remset .
Do it once,
I was fortunate to have a fabulous mentor, he and partner were chosen to compete in the " Plymouth Challenge" placed top 3 iirc.
Thank-you Ed Leippi, Victoria B.C.
Cheers .
 
Last edited:
All the bolt holes were drilled about 1/4" too low and cause a decent port misalignment.

And you're right, looks like these headers were designed with 273/318 manifold ports or thereabouts.

It all works okay but who wants to settle for that.

Love the stories and input, hoping to intercept power tour when it comes through town so I may be doing some of the sunday night mechanic stuff if only temporarily.

Wish me luck
 
65TerrorCuda said:
View attachment 1716103598

View attachment 1716103599

View attachment 1716103600
Look what happens if I line up the ports on these Sunday night rebuild gaskets. Fixable but annoying.
Click to expand...
Those look like the Fel-Pro ones for cast iron manifolds. I have a pile of them as they are what comes in the whole engine gasket kits.
They seal great on manifolds that are flat, but do not work on headers very well.
I have had good luck with the factory Hooker. MR.Gasket and some other white one's. The Fel-Pro ones were fine. The Edlebrock worked well too.
Clean and Flat is key and most will work fine.
In fact that I use the white ones to mark cast iron manifolds i port.
 
Last edited:
^^ excellent info, thank you!!

I'm considering clamping the header flange to my drill press and end milling the bolt holes to elongate them. Rat tail filing would take forever
 
A carbide burr in a die grinder works to elongate too
 
You must log in or register to reply here.
-

Back
Top