924Board.org

[Mike9311]

I have been rebuilding a waste gate for the '82 and now also for the CS

Discover the issue at final assembly on the first one which I was hoping to be a 5 minute job with what I had left to do. Yeah right, it never is

In order to get the valve to seat (make contact) I had to leave the nut loose which I wasn't going to do? My minds eye started set an alarm with a recent memory of the CS waste gate valve. The valve and seat were covered in carbon which means it was not seated.

What is happening is the aluminum plate that holds the diaphragm wears against the valve stem shoulder and/or the same part hits the valve guide.

Solution will be a custom spacer to place on stem between shoulder and then widen to spread contact area on to the diaphragm plate/spring cup. This will lengthen the valve stem to create contact at the seat. You could machine the seat flat to allow the seat to go into the body a bit more too. This wouldn't effect boost like my other solution. Just depends if its a small amount of material or not. The valves are not really worn either.







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1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

[Fasteddie313]

Is say deck the seat a good bit so it’ll have a lot of room to wear in..
Unless your custom spacer idea is just modifying a washer a little bit..

Pretty sure mine hit the seat first when putting it together, slightly compressing the spring..
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80 Turbo - Slightly Modified

[Mike9311]

Sounds like you had no issue

We shall see. The spacer would just be a custom washer or two. One to space and a second to spread load contact area past worn spot. Or it would be one washer with a flange to achieve the same result

Just glad I caught it on either one.
_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

[Mike9311]

So the real culprit was just found. The replacement guide had the larger diameter "land" or shoulder (better word) in the wrong spot. I also see that this was corrected from the supplier given that I just bought another one for the CS which matches stock dimensions exactly.

The guide didn't go far enough into the body of the wastegate leaving it higher or protruding more into the Spring area thusly allowing the contact to the spring cup.

Will correct and move on. Not a big deal
_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car