2.8 head, exhaust port stud problem.

**S4James** · 10-17-2016 02:15 PM

Well this is fun:

It appears these early AHA 2.8 heads were not predrilled under the exhaust ports to allow for mounting the 2.7 manifolds.

Learn something new every day.

The machinist missed it, and I didn't know this was even a possibility.

By the looks of it, they just need to be drilled out and tapped. A giant pain, but not catastrophic.

**aysix** · 10-17-2016 02:21 PM

Drilling and tapping that will suck. Sorry.

**S4James** · 10-17-2016 02:25 PM

well I aint doing it. Machine shop that built the engine is going to have to figure that one out.

**Zba** · 10-17-2016 02:55 PM

Any good machine shop should be able to handle that no problem. Are these the same heads with the oiling bars above the cams?

**S4James** · 10-17-2016 04:00 PM

did not notice anything like that.

**KSEADUB** · 10-17-2016 11:50 PM

Originally Posted by Zba

Any good machine shop should be able to handle that no problem. Are these the same heads with the oiling bars above the cams?

Should be, with small bars that run along the tops of the cam caps. ATQ heads upgraded to the oiling internal to the cam caps.

Sent from my iPhone using Tapatalk

**S4James** · 10-18-2016 05:17 AM

these are AHA heads... I saw no such bars, but these were bare heads.... Is it possible im missing oiling components? any way to check?

NM... i found a diagram... my cam retainers never had those external oiling ports... Must have been another variant from before '98.... cars have been around since 96 so they updated the oiling on the AHA heads as well.

**KSEADUB** · 10-18-2016 01:41 PM

Originally Posted by S4James

these are AHA heads... I saw no such bars, but these were bare heads.... Is it possible im missing oiling components? any way to check?

NM... i found a diagram... my cam retainers never had those external oiling ports... Must have been another variant from before '98.... cars have been around since 96 so they updated the oiling on the AHA heads as well.

Interesting. I wonder when the changeover occurred then. The only AHA heads I have seen show the oiling bars.

Sent from my iPhone using Tapatalk

**AudiMyMindS4** · 10-18-2016 04:35 PM

I'm actually looking to pick up some '98 AHA heads. Just to clarify, these are from a pre-1998 AHA?

**S4James** · 10-18-2016 04:58 PM

a 1998 aha.

**KSEADUB** · 10-18-2016 07:09 PM

Originally Posted by AudiMyMindS4

I'm actually looking to pick up some '98 AHA heads. Just to clarify, these are from a pre-1998 AHA?

Originally Posted by S4James

a 1998 aha.

So is that the cutoff? Pre-98 have oiling bars, 98 and on have oiling internal to the cam caps?

Sent from my iPhone using Tapatalk

**S4James** · 10-19-2016 05:13 AM

I really have no idea.

**Corradovolksb** · 10-19-2016 06:44 AM

I had the same issue when I installed 2.8 heads on my friends motor. I sourced the heads from the junk yard and they came off an a6. I didn't think anything of it until I went to install be exhaust manifolds and what do you know studs where missing. I had thought about attempting to drill the holes and tap them myself but didn't want to risk drilling too deep or at the wrong angle so I modified the manifolds to work. It was a pain in the ass but it worked. This is The best picture I have of the ssac manifolds I modified to fit. Used a drill press to drill the holes.

**S4James** · 10-19-2016 06:56 AM

Yes I ended up getting more information after my initial finding of your old thread. I had thought of the same thing, just drilling new holes in the manifold flange, but, since I am reusing my stock manifolds this is not an option for me (no material there)... Plus the 2.7 gaskets that i already have would have to be modded too.... I'm just going to tap the heads....

I had a look yesterday and it should not be a huge deal. Just costing me time. The machine shop is going to take care of everything for me. Its definitely a shared oversight so they are being very understanding.

In all my googling, you and I are the only ones Ive found that have posted about this issue.