grobb284

iTrader: (9)

Does anyone know where a mating flange for a header pipe to match the oval exhaust manifold exit flange can be found?

Thanks for responding.

Robin L

Currently I don't know of anyone that is making these. I am sure that there is a conversin company somewhere.

I would have them made. Find a company that has a laser cutter. I have had a company make header flanges that don't exist.


You might find someone with a take off.

Robin

grobb284

iTrader: (9)

Thanks for responding, Robin.

The flange appears to be more than a flat piece to be laser cut, it also has an undercut for the gasket.

I may need to find some damaged header pipes from the factory.

Anyone else have a lead?

Hard Core Z28

You do not need special header flanges. Round works just fine.

grobb284

iTrader: (9)

Hard Core Z28, here is a picture of the LS7 bottom exhaust manifold flanges, not sure how a round flange would match up from the header pipe.

Hard Core Z28

Sorry i thought you ment the header flanges. Sorry. Good luck in your search.

405HP_Z06

iTrader: (11)

You should call Street & Performance, they do a TON of engine swaps. If the parts are available, they will know.

grobb284

iTrader: (9)

Encouragement is a great tool, thank you.


405HP_Z06, thank you, I have used their parts in other swaps, excellent suggestion. Their block hugger four into one header is somewhat similar at the collector, wonder why I didn't remember them.

98Z28CobraKiller

iTrader: (17)

Yeah, I was gonna try to use a set of these manifolds for my turbo build until I saw the flange and also noticed that a custom motor mount would be required in order for it to fit in an fbody.

68lemans

iTrader: (17)

I might be making a few in a week or 2 .......i will be intouch.

jmilz28

iTrader: (13)

We're blessed in Houston to have so many job shops, metal fabs shops, and the like. If you have the budget, most anyone with some talented welders and a CNC machine will make what you need. PM me and I can recommend you one if that would help.

grobb284

iTrader: (9)

I have already made the Autocad drawing, and we too have a number of precision shops in our area.
Like anything else, if it is already mass produced, that would be the less expensive way to go. That is the reason for my inquiry.

If someone wants the CAD drawing and can produce parts in trade, PM me.

Lurk

iTrader: (11)

I'll be watching the thread. I'm going to use these manifolds in my swap and got the mid-pipes for this reason. Might not be hard to get a one off set from someone who has upgraded their exhaust over on the vette forums.

I paid $150 for the mid-pipes with cats...

FastKat

iTrader: (10)

I notice someone said that the flange had to have a recessed portion?

If it is anything like the C6 6.0L exhaust, I wouldn't worry about it. That gasket is a metal crush-style. It is flat with a raised lip around the circumfrence of the exhaust hole. As you tighten the flange to the manifold, this raised lip will crush and make your seal.

As a result, a flat flange should be fine. I don't think it necessarily needs a recession on both flanges. If anything, you could screw it up by making it too deep.

grobb284

iTrader: (9)

Too late the drawing has already been made. Here is a photo of the GM factory mating flange with what appears a recess in it.



Sometimes on a crush seal both parts have a similar depth, so that the outside actually bottoms out to make a uniform seal on the inside.

Lurk

iTrader: (11)

Interesting. I just looked at my set, and both flanges have this recess (manifold and collector side both). The crush gasket has a bead at that position that locks in the groove to seal.

With that said, any decent machine shop can make these according to your drawing. I've had my father in law take a drawing to work and ask their machinist in house to do some axle flanges before. For the price of a case of beer.

I have also used a small machine shop to modify brake parts. It usually isn't too bad. I guess I agree with jmil, we have options here.

PM me if you want me to try to pursue a machine shop for you here on a set.

FastKat

iTrader: (10)

What kind of software do you use to make drawings for CNC machines, etc? Is there any free software floating around out there that gets the job done?

grobb284

iTrader: (9)

I used a version of Autocad, only because that is what I am familiar with. Satisfied with drawings are pretty close to factory part. Did one in .dwg format for a basic print and dimension checking, did two drawings in .dxf format for machining on computer controlled mill, wire edm, or laser.

One person has sent for drawings in exhange for parts, anyone else?

Troux

iTrader: (4)

Could talk to these guys:
http://www.ls1gto.com/forums/showthread.php?t=260523

Otherwise, why not just custom-made headers?

grobb284

iTrader: (9)

These headers are just right for my project. I need a header that exits almost central to the motor, as I am running side pipes. See photo in signature.

Also, even though they are from GM, and are mass produced, they have to be one of the more expensive headers produced, as far as design time and tooling. I don't know of any aftermarket headers that took the time or expense to hydroform the tubes.





The shrouding of the integral cover with dead air space may keep heat in, as well as not letting as much heat out.





GM made them in stainless, a superior material for long term use. They also polish up nice, like a art-deco piece from the '30's.




They must flow pretty well, they are using them on the supercharged LS9, the most powerful engine that GM sells to the public.