Aussie head/port divider question: for those that bolted it

[CobraSix]

I have a question. I think my epoxy failed due to the difference in design of the Aussie head versus the old us log head. Not having the grooves on the aussie head seems to have put too much stress on the epoxy. It sounds like it broke lose, as I have an unrythmix metallic tapping coming from the vicinity of the #4 exhaust tube.

So, I was thinking of using the old heat tubes (or whatever you call those two bolt holes on top of the #3-4 exhaust port) and drilling them out and putting some new bolts in there to hold the exhaust port divider in place. I really do not want to have to remove the head again (mainly because the headers and intake are finally sealed up with no leaks...don't want to go pulling them apart again, major PITA).

Can I just tap the hole down to the port divider?

Do I drill out and just use the threads on the head?

How far should I drill to the divider?

Any help would be great.

Slade

 

[addo]

My suggestion...

Drill out the heat riser tubes. Drill a little into the divider, too. You'll need the clearance. Tap the holes UNC, maybe whatever gauge is about 1/4" or closest to original. You'll barely start the threads with an intermediate tap, then go to a plug tap with a bevel ground on the bottom, finishing by grinding the bevel to nothing. Use compound or risk breakage.

The set screws should be hardened steel and pointed. They also need to be shorter than the hole, as Omega65 mentioned. Snug home and mash over the thread profile above them. A tighter than needed fixing will back out faster and you risk a first - cracking a 2V head (not known of any, ever).

Hope this helps.

 

[Anonymous]

I too, had an exhaust port divider that started ratteling in my Aussie head after I had everything together and running, when I saw your question and answer of May 7th. It sounded like a good idea so I drilled out the front tube hole using a 17/64" (.2656") drill bit as my Sears taps suggest for a 5/16 - UN18 bolt. At about 5/8" I broke through into the port and hit the divider. I drilled into the divider just enough to put a bevel mark on it, then I tapped the hole. I then took a 5/16 x 1 1/4" long HS bolt,
and starting about 5/16" from the end tapered it to half the diameter at the end. I installed the bolt with a nut on it to lock it in place once the bolt solidly hit the divider. It worked !!! No more rattle, and it only took me an afternoon !!! But now I hear valves. Thanks for the advise. I never would have thought of that myself.
Hot rod Bill

 

[Anonymous]

I don't have one in mine and don't plan to as I can find nothing to prove it adds anything. Even Ford OZ did not use it.

 

[CobraSix]

I can't imagine it making anything worse though...but good point. YOu think Aussie Ford would have made one if they thought it was important enough.

Slade