Should I cut my header flanges for better seal?

Posted By: DusterDave

Should I cut my header flanges for better seal? - 02/21/13 03:07 AM

I'm building a set of headers, and thought I read somewhere that its a good idea to remove these sections of the header flanges (marked in green), because there will be less chance of warping, and therefore, less chance for leaks. Is this true? BTW, these flanges are 3/8" thick.

Posted By: DJVCuda

Re: Should I cut my header flanges for better seal? - 02/21/13 03:09 AM

I'd just buy a set of remflex gaskets and be done with worrying about any leaks PERIOD...

Posted By: topside

Re: Should I cut my header flanges for better seal? - 02/21/13 03:33 AM

I cut those sections out for a few reasons:

Reduced warpage
Improved spark plug access
Less heat around the wire/boots
Better appearance
Less unnecessary weight

Never had a leak since I started doing that decades ago.

Posted By: MR_P_BODY

Re: Should I cut my header flanges for better seal? - 02/21/13 03:51 AM

Quote:

I cut those sections out for a few reasons:

Reduced warpage
Improved spark plug access
Less heat around the wire/boots
Better appearance
Less unnecessary weight

Never had a leak since I started doing that decades ago.

Yep...

.... I always cut them... the expansion
rate is different from the outer cyl to the center...
cut them and get that chunk out of the way... and
be much happier all the way around
EDIT
Also ... make one of the holes larger than the bolt
so it has room to slide.. otherwise something has
to buckle (on EACH pipe or SET of pipes)

Posted By: justinp61

Re: Should I cut my header flanges for better seal? - 02/21/13 04:02 AM

Quote:

I cut those sections out for a few reasons:

Reduced warpage
Improved spark plug access
Less heat around the wire/boots
Better appearance
Less unnecessary weight

Never had a leak since I started doing that decades ago.

Me three.

Posted By: Leigh

Re: Should I cut my header flanges for better seal? - 02/21/13 04:18 AM

Weld an on edge gusset bridge, on the top face of both center tube flanges, to help with edge pull down. Next best thing to the third bolt, that isn't there. Oh yea. Cut the connecting material out.

Posted By: DusterDave

Re: Should I cut my header flanges for better seal? - 02/21/13 05:06 AM

Thanks, guys! I will cut away, and oval/oversize one hole on each flange.

Posted By: smokinwoody

Re: Should I cut my header flanges for better seal? - 02/21/13 03:45 PM

as Mike says...and many other manufactures...yes cut them but maybe not as much of a chunk..

I have Doug's headers..here's what they do and they too have thick flanges..

Posted By: HEMIFRED

Re: Should I cut my header flanges for better seal? - 02/21/13 05:20 PM

Quote:

Thanks, guys! I will cut away, and oval/oversize one hole on each flange.

I cut them and make holes one or two drill sizes larger
no gaskets just ultra high silicone

Posted By: Sport440

Re: Should I cut my header flanges for better seal? - 02/22/13 12:04 AM

Quote:

Thanks, guys! I will cut away, and oval/oversize one hole on each flange.

Yep cut them, but I wouldnt cut them until your headers are all welded up. You probably know that already.

Posted By: earthmover

Re: Should I cut my header flanges for better seal? - 02/22/13 01:40 AM

no gaskets just ultra high silicone

my buddy thinks I am crazy when I tell him that... that's all I have ever used on my small block, and never a leak

Posted By: HEMIFRED

Re: Should I cut my header flanges for better seal? - 02/22/13 02:11 AM

Quote:

no gaskets just ultra high silicone

Quote:

The Loctite 59675 is a Superflex� RTV high temperature red silicone adhesive sealant.

Loctite 59675 Features:
Resists aging, weather, and thermal cycling without shrinking, cracking, or hardening
Applications: automotive gasketing, industrial furnaces, boilers, ducting
Temperature range: -75�F to 600�F (-59�C to 316�C)
Container: 300 ml cartridge
Consistancy: paste
Gap fill: to 0.25"
Color: red