Where does the one odd exhaust port cavity go to?

My heads are gt40p, but I think all heads would be similar. When I blow air through the 2nd or 3rd exhaust port, depending on which direction you start from, it comes right out the intake side from the hole in the very middle of the head (see photo). This is not a leak, this is a direct, free flow coming out the hole.

What is this hole for? Apparently it goes into the intake manifold, or is blocked by the manifold (not sure which, it is currently still on the car).

The Fel-Pro intake gasket set includes a "plug" gasket to cover this hole if not used. I guess I should use it if that port does not go somewhere on my intake manifold.

Does this exhaust port, having this extra cavity in the other side of the head, flow differently than the other 3 (or 6) ports?

 

That is an exhaust crossover (I thnk that is the name) I believe it was created to run hot exhaust (or maybe it was water) through the intake to warm the mixture. Or somethong like that. Your aluminum manifold will block it off..

 

Thanks. Brief, to the point, and EXACTLY what I needed to know!

 

In the original application that passage is for Fuel Injection EGR operation.

 

Nope. It's just an exhaust crossover. Does just what Scotty said.
Your manifold may or may not have a passage to go between the heads. Not having it won't hurt anything but cold driveability, but you shouldn't be driving your car when it's cold anyway.

 

Whats wrong with driving it when it's cold? I'm sure I'll be driving mine to school many mornings when it's 19 or 20 degrees outside in the comeing winter months.

 

yea, but he's from the north. He doesn't have these southern winters, they have salt on the roads.
The only problem I ever had with winter driving is the length of time it took my heater to start working.

V8s make mo'powa' when its 30*F.

 

Heater? Guess I should have kept those hoses coming from the firewall!! LOL

 

I live south of Houston, about 20 miles from the Gulf. Can't get much more south than that. I typicallly drive it daily in the winter, if it is not raining. Seldom drive in the summer, unless we have a cool afternoon. Which is almost never!

 

Consensus is...if intake manifold has the passage, use it, if not, plug that chunk of gasket in there.

Any other suggestions?

 

courier, what do you mean 'NOPE' it's just an exhaust cross over.
The heads are from an EFI application that uses the port up through the intake to the EGR if those intakes are used. No if's and or but about it.
Take a look below! Think maybe I ought to know!

 

the cross over is not just on EFI heads maybe that is what he was saying

 

Jamie-
I meant without warming it up.

Bluegrass-
I must've missed the fuel injection system on both my engines when I tore them down.
('72 originally in the Maverick and '68 I built to put in the Maverick)

 

Scooper, I would plug it regardless. The last thing most of us want is to heat up our intake anymore than it already gets.

 

I want to take a moment to set straight a few things about my posts on this board.
First I don't deal with B.S.
I always give in depth answers where prudent and I think there is important need.
I can assure all that I have been working in the Ford arena for a very long time from Model A's, Model B's, Flatheads, Y blocks, big block, and all the engines right up to the present modern motors in one form or another, built and raced nearly all of them over the years as well as other makes and single cylinders engines, motorcycle DOHC in midgets.
To be told I'm wrong by those who need some more education about some topics won't be left set on the deck without answer.
I have been on this board since 1995 and see it is beginning to look like a ricer board with all the nonsense that has been flowing lately.
Sorry if it doesn't set right with some but that's the way it is.
If anyone thinks I'm just bragging, lets talk EEC'S modern Power Train Control Modules, engine diagnostics, Fuel Injection and see who's a B.S. artist.
If you don't want accurate info , that fine to. It's not my loss.