7A engine conversion

[ridgeracer]

does anybody have experiense on converting 7A block and head to ADU specs ?
is it strong enough ? i know about the diferense in bore, but is there anything more i need to know ?
thanks !

[Corey]

7A head needs machining for the water manifold plus the valves are the wrong spec.

[volcano rs]

7A head needs machining for the water manifold plus the valves are the wrong spec.

i read somewhere that the exhaust valves on 7a are sodium filled which are same as s2 i'm i right ?

[ridgeracer]

im considering this conversion since the 7A engine is much cheaper here in Norway than the ADU/AAN..

[Corey]

i read somewhere that the exhaust valves on 7a are sodium filled which are same as s2 i'm i right ?

I don't think they are but as always willing to be proved wrong

[S2 Ant]

sodium filled valves are used on the 7a heads - some 7a are not sodium filled.

Thats good enough for me, taken from the MRC section.

http://www.s2forum.com/forum/showthread.php?goto=newpost&t=14274

[ridgeracer]

valves spec ?
diferent size or?

[volcano rs]

Thats good enough for me, taken from the MRC section.

http://www.s2forum.com/forum/showthr...ewpost&t=14274

i didn't read it on that thread but read it somewhere else

[mcandmar]

I have an original Audi workshop training book at home for the 7A and it has a section that talks about the sodium filled exhaust valves, i remember reading it as it tells you how to dispose of them. It was something like cut valve in two, place in bucket of water and quickly retreat 5 meters away

There was mention on the forum here that only the early upto 1990 models with the 5-1 manifold had the sodium valves, 91 onwards with the cast manifold didnt apparently. Not sure it thats true. From what i've seen the early heads only had two studs per exhaust port where as the later heads had the extra stud holes machined so an S2 manifold would bolt upto it.

[Jamo]

I don't think they are but as always willing to be proved wrong

The 7a manual says they are sodium filled.

http://www.s2forum.com/forum/attachment.php?attachmentid=3938&stc=1&d=1101671337

[Audi Parts Guru]

The part numbers for the 7A and 3B/ABY/ADU exhaust valves are different. They are both 98.2mm in length, however I can't confirm the valve head diameter

027 109 611D........ 7A
027 109 611B........ 3B/ABY/ADU

[mcandmar]

Can you check the part number for pre 1990 and post 1990 7A's, curious to see if they are different...

[twoqu]

Hi!

Does look as though, at least on the parts listings, that the NM/7A used the 611D and the 3B/ABY the 611B.
Strangely I was talking about this last night with SteveH. He pointed out that the 7A valves from the head he has have the distinctive shape of sodium filled valves. They also appear to be non magnetic on the valve face. We applied the same test to some ABY valves with the same result.
I have just checked some other valves and it looks as though the top parts are magnetic and if you move the magnet down the stem there comes a point when it becomes non magnetic. I'm not sure why this is the case or whether it is a valid way of identification.
Perhaps both the 611B and 611D are sodium filled but the material spec is different to account for the turbo aplication. Some naturally aspirated engines also use sodium filled valves.

[Jamo]

Does anybody have any idea how much it costs to convert a 7a head to ABY spec

MRC have been impossible to contact to ask about the price!

[Corey]

See here but deduct 10% from the prices shown if you buy through me.

http://www.034motorsport.com/product_info.php?cPath=28_63&products_id=361