cutting header flanges

Do you guys have luck cutting flanges apart to let the bolts seal the individual cylinders or leave the flange intact? Do you'uns run gaskets or red silicone? Right now I have a nasty spit on a 440, getting ready to use the red but I have changed headers twice already in the gasket's defense.

 

Never used the red, but i have used the high temp black Permatex stuff..It look's like a graphite color rather than the gloss black RTV..
I've had very good luck with that stuff....
Can't give any advice on cutting the flanges though, never done that..

Tony

 

I had trouble sealing a set of headers on an Olds 350. I even had the headers planed on a head milling machine and used copper gaskets-no luck. The only thing that sealed them was 2 paper style gaskets glued together with high temp rtv silicone and high temp silicone on each side of the gasket.

 

Yes,the paper gaskets work better and last longer,
if the are coated in Silicone both sides.

 

I too had the same problem, Cut flanges and used the red hitemp RTV and havent had a leak since.

 

Real race cars run individual flanges.

The long one piece flanges are a m*** production short cut.

 

Keeping the bolts tight has always worked for me better than anything.

 

run stock exhaust manifold gaskets they won't blow out like the paper header gaskets do.I haven't done it but one of my sons friends told him this and he ran a 350 with headers for over a year in his daily driver with no blow outs so I guess it does work well.

 

Leon renaud's right.

The paper header gaskets do fairly well in the sealing dept, but the brand I used melted like Kleenex (tissue to the down-under gang) when water got on them.

Stock header gaskets work best of all.

As Unkl Ian says, the long flanges are a manufacturing shortcut, but so are the long paper gaskets.
Touted as being an aid to installation aid.
Maybe, lots of ways to get the stock gaskets in.

I've had cut flanges on my 32 for 14 years and 48,000 miles.
Done for dipstick clearance.
No problems.
Done the same with other cars.

My 31 on 32 rails car gets individual flanges.
And stock gaskets.

 

I run a thick paper with no sealant of any kind. One thing you can count on during the weekly bolt check is that the header bolts will get close to a 1/4 turn.

 

Use red RTV on header bolts as a locking device.
Put it on the bolt threads, scew em in, apply normal torque.

Never had one come loose.

Recommended by a very experienced small town speed shop.

 

Well, thanks to all. Looks like the answers run the gamut. We always cut 'em when we were 18, but now I don't know if it was the right thing to do. Probably is, I know keeping 3 separate flanges straight during construction would be tougher than one. I did always run red sealant only on my circle track corvette manifold motor with no probs. Also, this RB Dodge has studs. The stock gaskets blew out with the first plug fire it seems. Got Mr. Gaskets on it now and one is blown out on 4-6. I think I'll cut them and run the red. I finally got tags on the truck!!!! Go to youtube and search 46 Dodge!!!!

 

i had some issues with the b motor in my dart, removed the studs as they made it real difficult to try to remove the blown out gasket. went with the copper gaskets with a thin film of the hi temp rtv. no leaks. no blow outs.