Cutting header flanges - bad idea?
Thread Starter
Joined: Nov 2005
Posts: 1,933
Likes: 4
From: Central Texas
Cutting header flanges - bad idea? I have some AS&M headers that supposedly are known for having sealing issues with the flanges - would cutting the extra material between 1/3, 5/7, 2/4, 6/8 be a bad idea? ...I figure it would help...
Also, I posted this elsewhere but the y-pipe is such that I could easily swap in a Flowmaster merge. My exhaust has a 3" intermediate pipe. Would there be any benefit to using a 3.5" or 4" outlet merge with a reducer? ...the price difference is a buck or two so if I can get a little extra power or better sound, id like to get it
TIA
Also, I posted this elsewhere but the y-pipe is such that I could easily swap in a Flowmaster merge. My exhaust has a 3" intermediate pipe. Would there be any benefit to using a 3.5" or 4" outlet merge with a reducer? ...the price difference is a buck or two so if I can get a little extra power or better sound, id like to get it
TIA
My SLP headers came from the factory with the flanges cut away. I didn't have to remove the dipstick tube to install the headers and it makes getting to the plugs easier. I've had no warping or alignment issues without all the tubes being tied together.
On The Tree
Joined: Dec 2011
Posts: 109
Likes: 0
From: Kissimmee, Florida
Flanges r nice to have if ya ever want to remove later for some work but, I removed my flanges on my Mid's only 'cause I modded it. Have full weld exhaust now for zero leaks and no gaskets to leak or blow-out...
^ i think he means just take a cut off wheel or something and cut the flanges between the bolt holes/primarys, so it would still bolt to the engine, the entire flange would be able to seal better without high and low spots since each section/primary could move a little better on its own to seal to the head. 2 bolts would still hold each primary/flange section to the head.
My jet hots/hookers have that 2 peice drivers side header, so the flange is also 2 peices, They normally only leak where the slip fit is, not where the flange hits the block.
I assume you would still use a 1 peice gasket, just cutting the flange between primarys to releive any tension to help it seal better right? Its not the dumbest thing ive ever heard, Its creative, and it might work....i say go for it!
My jet hots/hookers have that 2 peice drivers side header, so the flange is also 2 peices, They normally only leak where the slip fit is, not where the flange hits the block.
I assume you would still use a 1 peice gasket, just cutting the flange between primarys to releive any tension to help it seal better right? Its not the dumbest thing ive ever heard, Its creative, and it might work....i say go for it!
Cutting the flange may make the problem worse on one or more of the ports at the head. Milling it will help but you have to see how bad they are by using a true flat edge to see if there is any twist in the flange.
