Previous Thread
Next Thread
Print Thread
5.9L Magnum Heads and headers (wont seal) #529875
11/18/09 03:35 PM
11/18/09 03:35 PM
Joined: Sep 2004
Posts: 2,093
oberlin, Ohio
Rapid340 Offline OP
top fuel
Rapid340  Offline OP
top fuel

Joined: Sep 2004
Posts: 2,093
oberlin, Ohio
Anyone know of a header that will seal well up against magnum exhaust ports? The Dynomax headers I had sealed fine up to an LA head (plenty of contact to machined area all the way around ex port) but the magnum exhaust port is raised and the bottom of the header flange opening barely overlaps the lower machined surface of a magnum head (under the exhaust port opening).


1971 Factory Appearing Duster 340 11.000 @ 122 mph
Re: 5.9L Magnum Heads and headers (wont seal) [Re: Rapid340] #529876
11/18/09 05:08 PM
11/18/09 05:08 PM
Joined: Jan 2003
Posts: 2,511
Tampa , Fl
MoparJoe Offline
super gas
MoparJoe  Offline
super gas

Joined: Jan 2003
Posts: 2,511
Tampa , Fl
Nothing off the shelf, I usually weld up the dog leg area of the flange and grind it flat, even some of the headers for late model trucks use the LA flange.

I usually weld up the bottom 1/4-3/8" then lay a Mr Gasket magnum gasket over the flange and mark what needs to be removed with a sharpie, crude but it works.

Re: 5.9L Magnum Heads and headers (wont seal) [Re: Rapid340] #529877
11/18/09 05:14 PM
11/18/09 05:14 PM
Joined: Oct 2003
Posts: 1,371
Costa Mesa, CA
C
chache876 Offline
pro stock
chache876  Offline
pro stock
C

Joined: Oct 2003
Posts: 1,371
Costa Mesa, CA
Quote:

Anyone know of a header that will seal well up against magnum exhaust ports? The Dynomax headers I had sealed fine up to an LA head (plenty of contact to machined area all the way around ex port) but the magnum exhaust port is raised and the bottom of the header flange opening barely overlaps the lower machined surface of a magnum head (under the exhaust port opening).




I have dynomax headers that were on my LA360 that I reused when I swapped over to 5.9 Magnum engine. They didn't seal the first time out so I tried some new gaskets but used high temp RTV this time around and they seal up just fine now.

Re: 5.9L Magnum Heads and headers (wont seal) [Re: chache876] #529878
11/18/09 06:00 PM
11/18/09 06:00 PM
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick Offline
I Live Here
patrick  Offline
I Live Here

Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
summit long tube headers (I think they're flowtechs) seal up fine on my mag heads using copper RTV on the gaskets.


1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
Re: 5.9L Magnum Heads and headers (wont seal) [Re: patrick] #529879
11/18/09 06:51 PM
11/18/09 06:51 PM
Joined: Sep 2004
Posts: 2,093
oberlin, Ohio
Rapid340 Offline OP
top fuel
Rapid340  Offline OP
top fuel

Joined: Sep 2004
Posts: 2,093
oberlin, Ohio
My thinking is if the header flange seals fine on a magnum head, it may cover some of the lower part of the ports on an X or J head.


1971 Factory Appearing Duster 340 11.000 @ 122 mph
Re: 5.9L Magnum Heads and headers (wont seal) [Re: Rapid340] #529880
11/18/09 07:07 PM
11/18/09 07:07 PM
Joined: Nov 2008
Posts: 5,965
Greenville, PA
redraptor Offline
master
redraptor  Offline
master

Joined: Nov 2008
Posts: 5,965
Greenville, PA

Re: 5.9L Magnum Heads and headers (wont seal) [Re: redraptor] #529881
11/19/09 09:03 AM
11/19/09 09:03 AM
Joined: Apr 2007
Posts: 2,826
NY usa
5
540challenger Offline
master
540challenger  Offline
master
5

Joined: Apr 2007
Posts: 2,826
NY usa
I have hooker 1 5/8 competion headers on my magnum heads no problems here.

Re: 5.9L Magnum Heads and headers (wont seal) [Re: patrick] #529882
11/19/09 11:10 AM
11/19/09 11:10 AM
Joined: May 2004
Posts: 1,522
Ste-Sophie, Quebec, Canada
W
Wedgeman Offline
pro stock
Wedgeman  Offline
pro stock
W

Joined: May 2004
Posts: 1,522
Ste-Sophie, Quebec, Canada
That's the trick !!

Dan

Re: 5.9L Magnum Heads and headers (wont seal) [Re: Wedgeman] #529883
11/19/09 11:50 PM
11/19/09 11:50 PM
Joined: Jul 2003
Posts: 6,167
Maryland
GO_Fish Offline
master
GO_Fish  Offline
master

Joined: Jul 2003
Posts: 6,167
Maryland
you are not imagining this problem! There is only about 3/16" common area comparing the bottom of the LA port to the bottom of the Magnum port.

you're looking at an LA gasket crushed against a Magnum port.

5615711-mag-laport.jpg (57 downloads)
Last edited by GO_Fish; 11/19/09 11:52 PM.

Scott B. "I'm a self-made man... I started with nothing, and I still have most of it!" 68 360 rusty B'cuda 'vert (GO Fish)13.59@ 98.72 mph 69 340 GTS stock 14.18@ 95.60 mph 01 5.9L Ram 1500 Quad Cab 4x4 01 3.5L 300M 16.23@ 86.97 mph
Re: 5.9L Magnum Heads and headers (wont seal) [Re: GO_Fish] #529884
11/19/09 11:57 PM
11/19/09 11:57 PM
Joined: Jul 2003
Posts: 6,167
Maryland
GO_Fish Offline
master
GO_Fish  Offline
master

Joined: Jul 2003
Posts: 6,167
Maryland
I made sheet metal adapters, outside dimensions of the LA port, and inside dimensions of the Magnum port. Sandwiched the adapters against the magnum port with LA gaskets between the adapter and the manifold (or header). These adapters along with a Remflex gasket solved my leaks.

Some report a hump on the Mag heads that stops the manifold from sitting flat, I did not see that in my case. The Remflex gaskets are good enough that they may still seal without the adapter plates.


Scott B. "I'm a self-made man... I started with nothing, and I still have most of it!" 68 360 rusty B'cuda 'vert (GO Fish)13.59@ 98.72 mph 69 340 GTS stock 14.18@ 95.60 mph 01 5.9L Ram 1500 Quad Cab 4x4 01 3.5L 300M 16.23@ 86.97 mph






Powered by UBB.threads™ PHP Forum Software 7.7.1