piston is obviously burned,but the spark plug looks good ,egts are cold.so why no strap burn

I vote detonation as cause

Sounds like it might have been over timed and over fueled.

Rusty, It may have been a detonation issue, look closely at the burned area for small cracks!!
Where did the Piston burn? Thin side of exhasut valve relief??

it burned on the intake side. i am sure it is over timed.my Delema is to recognize this before it gets this far.i just can't figure why no strap burn.
how does over fueled figure into this

This message has been edited. Last edited by: rusty,

quote:

Originally posted by rusty:
it burned on the intake side. i am sure it is over timed.my Delema is to recognize this before it gets this far.i just can't figure why no strap burn.
how does over fueled figure into this

Over fueled and over timed causes it to light off fuel behind the rings. The over fueled part will hide "heat". This is usually how most nitrous guys tear/burn sheet up.

thanks, how to recognize on plugs early enough to prevent. When I think I can understand plug reading and then figure I cant,lol

quote:

Originally posted by rusty:
thanks, how to recognize on plugs early enough to prevent. When I think I can understand plug reading and then figure I cant,lol

That is the hard part. I have learned to tune fuel with the timing on the low side, then make it tell me to put timing in it.

quote:

Originally posted by 329L:

quote:

Originally posted by rusty:
thanks, how to recognize on plugs early enough to prevent. When I think I can understand plug reading and then figure I cant,lol

That is the hard part. I have learned to tune fuel with the timing on the low side, then make it tell me to put timing in it.

Would having AFR and EGT data acquisition be a help in this tunning and avoiding failure?

Where are those darn knock sensors when your need them? A quick search provided the following. Pretty spendy but maybe there's more out there?


https://www.tiperformance.com....-knock-detector-kit/

quote:

Originally posted by markemark:

quote:

Originally posted by 329L:

quote:

Originally posted by rusty:
thanks, how to recognize on plugs early enough to prevent. When I think I can understand plug reading and then figure I cant,lol

That is the hard part. I have learned to tune fuel with the timing on the low side, then make it tell me to put timing in it.

Would having AFR and EGT data acquisition be a help in this tunning and avoiding failure?

It didn’t help this time, everything was normal…

quote:

Originally posted by Canted Valve:
Where are those darn knock sensors when your need them? A quick search provided the following. Pretty spendy but maybe there's more out there?


https://www.tiperformance.com....-knock-detector-kit/

We did talk about adding one, i have no experience with one tho

quote:

Originally posted by seabass:

quote:

Originally posted by Canted Valve:
Where are those darn knock sensors when your need them? A quick search provided the following. Pretty spendy but maybe there's more out there?
https://www.tiperformance.com....-knock-detector-kit/

We did talk about adding one, i have no experience with one tho

I do some tuning on newer GMs, and ill tell you what, the damnbest things will set off a knock sensor, including loud exhaust, and or headers. Also seen loose converter/flywheel bolts set off knock sensors. So if the knock sensors are hooked up to a timing retard, just understand, the timing might move back and forth a BUNCH going down the track.

quote:

So if the knock sensors are hooked up to a timing retard, just understand, the timing might move back and forth a BUNCH going down the track.

While that's certainly an undesirable performance attribute, if used during T&T, and with enough retard to feel it in the seat of your pants, it could help lead to an acceptable tune where they're no longer needed.

quote:

Originally posted by Canted Valve:

quote:

So if the knock sensors are hooked up to a timing retard, just understand, the timing might move back and forth a BUNCH going down the track.

While that's certainly an undesirable performance attribute, if used during T&T, and with enough retard to feel it in the seat of your pants, it could help lead to an acceptable tune where they're no longer needed.

On their cars things get expensive in a hurry when it goes wrong though. Not sure the risk is worth it.

quote:

On their cars things get expensive in a hurry when it goes wrong though.

I'm no doubt out of my league.

thanks for the info