[uiuc240]

Here's the thing...Nissan motors don't usually have problems with piston rings or valve guides. 9 times out of 10, on an SR, the problem is that the turbo is toast. I'm even more inclined to believe this, since you say it happens all the time, especially under boost.

Easy way to check? Take off the hotpipe from the outlet of the compressor and look and see if there's a LOT of filmy oil in your intake. Now, a little bit is totally normal and not a problem, but if it's like gooey and getting all over the place, your turbo is toast.

Oh, and then take the intake pipe off and check the turbo for shaft play. A little is normal...a lot means the journal bearings are toast.

I'd bet that your problem is turbo related.

Eric