Would a broken exhaust spring on an exhaust valve cause reversion? Any opinions appreciated

388 sbc chevy's

I don't think so, water should not be getting back to that level in the first place. The broken valve spring is certainly going to cause a whole host of other problems though. You are running small blocks arn't you?

Yep! I just fixed a bent exhaust valve that caused a tremendous amount of reversion. I had the dreaded chocolate milk oil.

Yes. If the spring is broken, the exhaust valve wont close. So, when the piston is in the suction stroke, it'll suck the water in from the exhaust.

DAVE

Yes I did it last year and had to pull a set of heads and fix them