Piston rings cracking?
 

Not that I've had any but what would cause this to happen?

Re: Piston rings cracking?
 

Detonation!!

Re: Piston rings cracking?
 

That action seems to mess up a lot of things in there. :p

Re: Piston rings cracking?
 

Yea!! Interesting how motors tend to make their most HP and Torque right on the ragged edge of detonation. Drag racers really push the limit!!! If we try that with our boats we will have problems for sure!! My first experience with detonation was when I lost a center electrode on a spark plug on a 11.5:1 compression SBC about 12 years ago. I thought it was a faulty plug until it happened again on a different cylinder. :D Turned out to be not enough octane!!!

Re: Piston rings cracking?
 

Ring flutter.

Chris

Re: Piston rings cracking?
 

Let's not forget about improper installation.
Smoking a doobie during assembly has been known to cause a few too. :D

Re: Piston rings cracking?
 

Like ring butting?

Re: Piston rings cracking?
 

Nah,,,,,,,,,like just being stupid with the ring compressor. Or maybe with the expander putting the rings on the pistons,,,,,,,,,,,,,fortunately, I haven't had that problem for a long, long, long time,,,,,,,,
My favorite is when I take an engine apart and look at the wear pattern on the rings to see if the previous engine assembler rolled the compression rings on the pistons, twisting the rings.

Re: Piston rings cracking?
 

Are they cracking or breaking? If it is the top ring then it is all of the above. detonation, poor fitting.. If it is the second then it can only be due to poor fitment.

In some rare cases where a few select jokers like to run the longest rod they can, you will develop ring problems when you bunch them together too tightly. this is because the piston will actually distort from excessive heat & lack of meat (you know what I mean) causing the rings to shift. in this case they don't crack, they just break.

Roby

Re: Piston rings cracking?
 

seen a backyard rebuild before that was done by hillbillys,they left ridge in bolck!!! :eek: and it beat the rings to pieces,Smitty

Re: Piston rings cracking?
 

A bad ring groove will cause the ring to flutter.This can break a ring. This could be because of excessive wear, or pitting in the grooves or a worn ring if re-using . An aluminum piston can wear out an iron ring just like it can wear a steel wrist pin. A reputable machinist took a look at a set of forged pistons I had and told me they were junk. The motor had sucked water, and the ring grooves were less then perfect. Nobody can really afford to play around with junk ! The best built boats still can develop problems. Check everything , And when you think it's ok, check again, if in doubt throw it out. I had to learn the hard way , when I was younger I didn't have the $$$ and patience.
I ended up wasting time and money. Now I have the money, and my time is more valuable ! BBB

Re: Piston rings cracking?
 

BBB is correct... I've seen broken rings in engines before and in most cases it was new rings being put on used pistons... I call this a hillbilly rebuild... more often than not.. the cylinder has more wear than the rings... but by just putting on new rings and grinding the valves... Cleatus and Harvey can then say they rebuilt the engine. The ring lands on worn pistons aren't perpendicular to the piston any more.. they have a worn taper. Putting on new rings causes the rings to flutter and be deformed within the ring lands. This leads to fatigue and breakage.