So I got my whole head machined and got a valve job with regrinded valves new seals etc because the seals were burnt up from the previous owners lean tune. So my head only has about 1000 miles on it and I just got tuned and made good numbers (indicating that comp #'s are good which means valves are still good) about 450 miles ago. However I just installed a wideband a few weeks back and now I can see that I lean out at full boost (to 13.1) and sometimes its really lean at idle (which I hear wont hurt anything) Im just worried that ive been running lean at full boost ever since I got the tune. I mean its not like ive been hitting full boost 24/7 lol maybe 10-15 pulls overall since ive got tuned and not all one right after another. My question is is it possible to ruin exhaust valves that fast? Im just curious. I figure with the lower burning temp of E85 that I wouldn't burn them up easily but you never know I guess.

If anyone knows if this is possible it would really help my worries lol

Thanks.

 

My limited experience suggests what you were told is maybe not correct. Valves can burn with any mixture if not sealing. With hot exhaust gases blasting through the leak the metal is eroded away. Leaks are caused by bad valve and seat grinding, loose valve guides which allow the valves to wobble, carboned up guides causing the valves to stick open or something stuck to the seat. Well, there's slightly bent valves which can occur if the engine is not kept in time.

 

With the valve not seated properly, you can torch a valve in a few blocks of driving.

Also it depends on what valve is installed, a stock cast valve will burn faster than a decent stainless steel valve.

If the compression is good, and the leak down is good, then you do not have a burnt valve.

The seat width plays a factor in heat transfer, a wide seat will cool a valve more than a narrow seat.

Too wide of a seat you get deposit build up on the valve.

Too narrow of a seat, the valve runs to hot and can cause pre det and/or burn.

 

Thanks for all the help guys!!