Ooooh... that kinda points to piston failure. You'll know if it looks like the wristpin was beating the cylinder.
Ooooh... that kinda points to piston failure. You'll know if it looks like the wristpin was beating the cylinder.
David S. Wallens wrote: Rub some dirt on it.
This had me giggling WAY harder than I should have.
How much power was this making?
Not much, it was at 13psi on the stock MSM turbo.
Here are some terrible cell phone pictures. The battery in my real camera was dead.
Pulled off the head today, one of the pistons doesn't look quite right.
Ugh. You know that scene in Fight Club when they take Bob's hat off and his brains just sort of goosh out all over the floor? This is exactly like that but metal.
There does not appear to be any indication of detonation on the pistons. Not sure how it happened. Could the ticking have been an indication of anything?
It could have been the rings flapping around if a chunk of piston broke off. The kid who worked for us last summer chunked #4 on his '95 Miata because the GT30 turbo he threw on it was making more and more power the more boost he threw at it. The rings jam hard into the cylinder from combustion pressure, getting hot and closing the gap, then they butt and get a kind of positive-feedback loop induced death grip on the cylinder wall, and the piston usually loses that battle. That is the low-power death method, the high power method does not require the rings to butt, a good solid detonation spike can force the rings hard enough to break a weak piston.
'Tis why my Audi engine has .024" top ring gaps in a 82.5mm bore. I do plan on boosting the everloving snot out of it.
Take a look at what is left of the rod bearing, if the upper shell looks pounded out, then you were definitely experiencing detonation. Don't forget that you also have three other piston/rod assemblies to check out as well. Detonation affects everything - ring lands, wrist pins, upper bearing shells, lower main bearings, main/block interface...
If I had the Volvo then I wouldn't mind coming down there to lend another couple pairs of eyes on it, but I don't get ownership until Monday.
This is what remains of piston #1, the rest is likely on the ground somewhere.
Knurled wrote: Ugh. You know that scene in Fight Club when they take Bob's hat off and his brains just sort of goosh out all over the floor? This is exactly like that but metal.
This is so metal. 
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