after my recent encounter with very lean vtec pull( yes it was stupid of me not to check)

i want to know where is the point of no return?

the motor in my sig while i was adjusting maps second vtec pull turned out to be very lean and i missed the afr gauge readings because it fell on the floor while i was accelerating.

later in neptune i saw it going up to 18afr from about6000-8500rpm ( second gear pull to 8000rpm)

i checked the spark plugs
checked the top of the pistons and checked for any weird noises.

everything was ok. no burned carbon deposits. pistons were black as always from normal carbon deposits.


theres a ticking valve that got a bit louder which was there from the begining.


what is the limit before the pistons melt/ engine blows up bearings spin etc...

how lean, how long what rpm etc.

did leaving oil squirters save this motor possibly?

 

From my extensive experiences in regard to blowing **** up, you'll melt the electrodes off of the spark plugs before you melt a piston. Your probably ok if it's still running. Wouldn't hurt to compression test it to see if you scarred up the cylinder walls badly, but I think your probably fine. If you really broke some stuff, you'd know it. It would be apparent in the form of smoke an some expletives.

 

lol thats good to hear.
no smoke at all during warm engine and only vapors on cold start

spark plugs are irridium 7 heat rating had a lil bit of silver dust coat on them but not melted or damaged in any way.

btw i didnt hear detonation( either because im deaf or to excited or there was none)
but i did see the AFR at redline out of the corner of my eye it was 17.8 right before i let off the gas. which i cant explain.

 

lean condition and detonation are two very different things, you can get away with detonation often times if you catch it fast, often times you will actually hear it or notice something is definitely wrong, so you have to be atune to your motor. The more horsepower it makes, the less time you tend to have before something goes horribly wrong, as the stresses on the components inside the cylinder are even higher then say a 120whp motor experiencing detonation. Lean conditions in my opinion, especially under high power high boost applications are worse to have for shorter periods of time because of the sheer heat generated. If your doing a 1/4 mile pass and you go 10-14 seconds of extreme heat due to a lean condition, often time your motor doesnt make it out the other side.