Ring lands lifting

[srsnow]

First thing I thought when I saw that was nitrous that was running too rich.

[rocketracer380]

its turbocharged 8.5 comp

[rocketracer380]

its turbocharged 8.5 comp

[rocketracer380]

rings were fine no butting im assuming adjacent to intake pocket was excessive rich mixture or is that with nos use only

[F-BIRD'88]

It was not too rich.. Stop dreaming.. Detonation caused it.

[FloydODB]

It was not too rich.. Stop dreaming.. Detonation caused it.

What caused the detonation

[Walter R. Malik]

It was not too rich.. Stop dreaming.. Detonation caused it.

What caused the detonation

Exactly ... or to much heat for whatever reasoning.

[FloydODB]

It was not too rich.. Stop dreaming.. Detonation caused it.

What caused the detonation

Exactly ... or to much heat for whatever reasoning.

And I've seen some bad detonation and never seen it, by itself, lift a land. Only a ring that has pressed itself in cylinder. ^ heat. Where's the heat. Combustion.
You need air, fuel, and spark and you gotta get it out. Af:ratio right? Octane right? Timing right? Exhaust getting out? <--turbo/cam timing? You can be within a perimeter or tolerance and the engine will be happy. May not be perfect but happy. Your engine is not happy.

[F-BIRD'88]

its turbocharged 8.5 comp

Too much boost for the fuel used. low octane.
Too much timing under boost with crap gas..
Too lean under boost.
If flat tops its more than 8.5:1
This is how forged pistons fail vs cast pistons that just break the ring land right in that spot for the same reasons.

[F-BIRD'88]

Lack of using an intercooler (or water methanol injection) to lower charge air temps under boost.
If blow thru carbed wrong fuel pressure regulation tied to boost . Incorrect carb jetting and or emulsion circuit ,power circuit tuning. power valve closing under boost. Lack of boost retard. Top ring end gap way too small.
Crap Gas... Did I mention Crappy gas@

[Tuner]

Need to see a pic of the piston top and what heat range plug was in it?

[jed]

You never said what engine just a “363”. Piston looks small in your hand.
Why the 8.5/1 compression. I’m not a tuner just a machinist but a lot of my customers run 10.5 to 12/1 on street engines on 93 octaine.
Most have chassis dyno’s or have access to a dump. Very seldom do they have a piston problem.
One thing that does come to mind is the boost controller malfunctioned and there was a boost spike. It only takes a nano second of 15/20 lb of boost to cause that to happen

[Roundybout]

Underside of the piston I’d like to see too. Ton of heat showing there would lead me to look at the tune. If it looks good I’d suspect it went lean for whatever reason. I’d expect the rings to be more damaged.

Question, when a ring butts, does it always lift the ring land where it butts or is it random?

[jed]

A picture I saved from years ago

[jed]

Rings butting is a relative term. What if the rings butted with .020 gap but if they had been gaped to .021 or .022 gap would they would they have butted. When the engine builder decided this application needs .020 end gap does it have it really have .020 or does it have .005 end gap. Who knows??
Now if the rings needed .005 or .010 more ring gap the piston ring lands, rings and cylinder wall would look different.
I think.