We were making a few WOT runs 2000 to 6500 rpm.

I have catch can PVC as well as breather in my Oil Fill,

I've always had a slight mist from the breather during hi load/rpm conditions.

Now I have lots of smoke & some oil coming out of the breather during hi load/rpm runs.

When the car idles there is now smoke & a pulse if you hold your hand over the Oil Fill.

No knocks or rattles, Oil Pressure is good, it sound as though there is a slight miss. Does not drive normal either with major smoke & oil coming from the breather.

The motor has 10 K miles, extremely well maintained & the only abuse is really on the dyno. The modifications were done maybe 2 K miles ago. The motor has run perfectly until this.

I tune myself & have always been quite fussy with AFR & KR. I target 12.6 AFR, at times we have had some knock but I have never turned off or desensitized the KR sensor's

So please do not be kind, just tell me what you think may have happened.

I do know their is problem's with some 01 LS1's & oil consumption, I think this is beyond that though.

 

You'll need to run a pressurized leakdown test on each cylinder in order to diagnose the issue. Anything less than this, or a complete teardown, is just guessing.