2.8 head question, timing parts.

[S4James]

Can anyone tell me if the timing chains, adjusters etc can be moved over from 2.7 heads directly to 2.8 heads?


I have a pair of AHA 2.8 heads that are essentially bare. just valves, springs, retainers, lifters, and cams... All the timing hardware was stripped from them.


My plan is to just bolt these straight on once they are checked out, (new valvestem seals, etc etc)....



But ill need to move the timing hardware over from my original (trashed) heads.



I believe this should be possible, but id like to hear from someone who knows better than me with my middling google skills.

[NOTORIOUS VR]

As far as I know all the timing parts should be usable. They're essentially the same casting as the 2.7T heads, just larger ports.

You will want to swap at the minimum the exhaust valves from 2.7T heads to the 2.8 heads.

Also make sure you're using the 2.8 cam caps that came with the heads. Do not swap these!

[redline380]

You will want to swap at the minimum the exhaust valves from 2.7T heads to the 2.8 heads.

Exhaust valves are actually the same. AFAIK, all 5v (inlducing 1.8t, but maybe not 4.2)heads share the same exhaust valve part number, 058109611E

[NOTORIOUS VR]

Exhaust valves are actually the same. AFAIK, all 5v (inlducing 1.8t, but maybe not 4.2)heads share the same exhaust valve part number, 058109611E

No they're not the same.

The keeper grooves are lower on the 2.7T valves to increase seat pressure. Either that or it's the intake valves. But there are differences.

[S4James]

No they're not the same.

The keeper grooves are lower on the 2.7T valves to increase seat pressure.

I have heard conflicting opinions on this one. I have both heads, so I will find out. Some tell me no, not needed to swap them over.. but yes the keeper groove issue is something Im also aware of.

[Zba]

Exhaust valves are actually the same. AFAIK, all 5v (inlducing 1.8t, but maybe not 4.2)heads share the same exhaust valve part number, 058109611E

The 2.8 and the 2.7 use different parts (APB and BEL use the same):

058109611E - APB exhaust valves
078109623E - APB exhaust valve springs
078109021P - APB intake cam cyl. 1-3
078109021Q - APB intake cam cyl. 4-6

058109611M - AHA ATQ exhaust valves
078109623B - AHA ATQ exhaust valve springs
078109021 - AHA ATQ intake cam cyl. 1-3
078109021A - AHA ATQ intake cam cyl. 4-6

[NOTORIOUS VR]

I have heard conflicting opinions on this one. I have both heads, so I will find out. Some tell me no, not needed to swap them over.. but yes the keeper groove issue is something Im also aware of.

They're different 100%... although it's been a long time since looking at them myself you will need to swap valves, then lap them into the head and replace all valve seals (obviously).

[redline380]

Someone better tell GAP then because they say the valves are the same

[S4James]

GAP?

[redline380]

Genuine Audi Parts .com

[Ephry73]

Glad to read these posts. Future build parts gathering


Sent from my iPhone using Tapatalk

[zillarob]

2.7 has the keeper grooves cut lower to compress the springs for more seat pressure. Helps keep them closed with higher ex mani psi.
Many ex brake kits for trucks come with stiffer springs for similar reasons.

[S4James]

The only question that remains, is how needed is that extra seat pressure?

People have been getting away without swapping the valves but I have not heard of any issues caused by this, or failures.



lastly, if one intends to upgrade the springs/retainers... It makes the entire thing moot.

[NOTORIOUS VR]

The only question that remains, is how needed is that extra seat pressure?

People have been getting away without swapping the valves but I have not heard of any issues caused by this, or failures.



lastly, if one intends to upgrade the springs/retainers... It makes the entire thing moot.

With FI you ALWAYS want more seat pressure.

IF you upgrade springs and retainers (which is what I would do because springs ARE a wear item) you HAVE to get upgraded exhaust valves at the minimum. The stock exhaust valves with upgraded springs have been known to fail and it's cheap insurance.

So either stick with all OEM 2.7T stuff and just swap everything over, lap them in and be done with it and settle for a lower REV limit, or buy new stuff so you can raise the REV limit and not have to worry about dropping a valve at 8000+ (if you have turbos to support that which you don't) and know that you have good springs in there to avoid valve float.

[S4James]

Yes thats right, I remember seeing a set of valves with the ends snapped off.. Long time ago.