After a head asket failure on my '85 Euro S, I discovered one of my exhaust valves was bent. From the dealer, a new one was app. 175 euros, so I checked 928Intl. (http://www.mailordercentral.com/928i...asp?number=928 105 410 04)
I received the part, but I have some worries, because it looks totally different from my other exhaust valves. I'll ask them about it, but would also like to have your opinions:
Attachment 539449
Left is teh new one; right is the old one. Main difference is the dish at the combustion side in the original ones, whereas the new one is flat, with only in the middle a small recess. Also, the original valve seems to have a welded on stem (notice the heated, black zone at the bottom of the stem). The new one also has a large vertical surface sticking inside the combustion chamber.

This all probably also leads to weight difference:
Attachment 539451
new versus the original one:
Attachment 539450

The numbers at the top of the stem is also different, so the new valve probably won't be a Porsche item:
Attachment 539452

Have I received a wrong part or will it be a good replacement?
In case it is correct, would it be an idea to put the new one in a lathe to reshape the combustion side shape and remove some weight?

 

Bart, I would just try and get a second hand one, they are quite plentiful, they are the same in the 944 from my experience. If you can't swap it for a used one I can have a look if I have a spare. I know the only potential spare valves I have are from a 944. If you luck out and I have one, my good deed for the day will be to send it to you free, you will need to pay the postage though.

With regards to the new valve you have there, I would be reluctant to use it as the triple groove system requires a hardened stem to withstand the valve rotating. So without knowing the provenance of the supplier to 928 intl. So that is the reason I would not use it.