Extra hole in Center Iron
 

Hey guys I'm putting together an S5 keg with S4 intake and noticed this extra hole beneath the lower intake manifold. is this something I should block off or do I need to use the S5 lower intake manifold?
This is a race motor with all emissions deleted ACV blocked etc.

Attachment 753131

Was really hoping to start this turd today so hopefully its not used.

ACV inlet to the exhaust ports.

If you didn't block it off internally, you'll have to cover it up. I have always cleaned that part of the intake manifold very well, drilled a couple holes and inserted a couple screws for some mechanical locking, then built the area up with some "metal putty". The stuff that comes in a roll and you have to knead with your fingers, works like JB Weld but applies like Play-Doh.

Then after a day to set, I file the manifold flat and it is done.

Here's an example of the finished product:

Attachment 617086

i just pound some aluminum U channel material into the port, a bit less work than dicking with the manifold.

Thanks guys. Thought i was losing it for a bit. Ill fill it up

if you don't fill it you will have a loud exhaust leak !

The putty stuff I use is called Quicksteel. Other markets may call it by a different name.