What do you think happened to these pistons?

M

Motorbreath

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Jan 29, 2008
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Found the messed up 800cc big bore pistons in the garage. Been sitting there for about two years now, lol.

What happened to them? I think I know. But, what do you think?
 

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i was thinking overheat of motor due to cooling system failure - they dont look lean - bearing on the one looks like it was hot and both outers get hotter than inners if you loose your anti-freeze.
 
i think i read something about a coolent leak doing this.(breaking the top ring land off from cooling to fast i believe)
 
snowdad4 said:
rings caught a port from a bad bore job or poor port job?
Click to expand...

I believe that the rings caught ports on their way down since there is a chunk of piston top missing on all three. Or that the pistons caught ports on their way up, seems less likely though.
I don't know if it's because of a bad bore job, a bad port job or if they were worn out causing the pistons to wiggle into the ports. Could be all three I guess.

Ignore the color of the bearings, that's just the camera.
 
are all the locating pins gone? are all the rings broken? looks like first one has heat distorted ring, twos ring looks like its there, and threes ring caught port by the look of it.just odd all breaks look identical shape and size. it looks like upper and lower ring lands are gone are they?
 
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no1chevyboy said:
are all the locating pins gone? are all the rings broken? looks like first one has heat distorted ring, twos ring looks like its there, and threes ring caught port by the look of it.just odd all breaks look identical shape and size. it looks like upper and lower ring lands are gone are they?
Click to expand...

Locating pins are there. Both center piston's rings are fine. Lower rings on the other two pistons look fine, the right one is nailed in it's position by some crap that probably came off the piston top though. Upper ring lands on left and right pistons are gone.
 
well if pins are there and rings are there, they couldnt have hooked the ports, once the tops broke though, the heat would distort ring and it may hook the port thats what no 3 looks like, to me they look lean (no wash) may have detonated but dont really see any signs
 
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