2.8L Header Flanges

[D Lenz]

Hello All
I am doing a custom build on a Ford Cologne 2.8L (74-79) and had one heck of a time finding header flanges ... so I designed/machined my own.
I designed them for 1 1/2" tubing (Hooker makes tubing and 3x inlet collectors) with a stop at the bottom which should afford good port matching and a positive stop for the tube to keep everything up tight.
I have fit them to the heads I have and everything seems to be OK but I will not be building the headers for several months (engine is not back from the machine shop). They are still a bit dirty so please excuse the big chunks.
Since I like sharing the resources, I am attaching the drawing files and a picture of the finished product.
As a side note: The drawings show a 'Z' drill for the bolt holes, however if one instead wishes a bit of a tighter tolerance might want to drill them using a 'Y' drill. The holes can always be opened up as needed.

Enjoy!

 

[fergusonic]

What keeps the header gasket from leaking at the bottom?

 

[D Lenz]

I guess I do not understand the question ... I made allowance so the air injector ports are blocked.

 

[sheep herder]

I guess I do not understand the question ... I made allowance so the air injector ports are blocked.

I think he's referring to the way the bolt holes are all on one side.

 

[fergusonic]

..... and the headers could not be tightened at the bottom because of no provisions for bolts. However, one may plug the emissions holes and , using the gasket as a template, drill and tap new holes at the bottom. I've done that to all of my 2.8 heads resulting in no "blow out" / leaking gaskets.

 

[D Lenz]

I planned to block off the air injector holes. As far as drilling lower holes, the old headers I built years ago only had the six bolt holes and were 1/4" thick, never had any leaks. These flanges are 3/8". Also small block Chevys only have bolts on either side of the exhaust tubes, however I guess time will tell. Thanks for the heads up.