what happened to the LS1 I bought - #7 piston busted
at the ringland.
05-11-2010, 05:44 PM
#43
By "psi ls motors", do you mean super/turbocharged engines? In that case, I don't think you would see this very often since the intent is to create manifold pressure, which would seem to be more likely to equalize pressure in the plenum better. On NA and nitrous engines, where I think this is most common, I would expect that you would get a ramming effect in the back of the manifold creating a denser air charge (re: leaner) for that #7 runner.
05-12-2010, 12:34 PM
#44
By "psi ls motors", do you mean super/turbocharged engines? In that case, I don't think you would see this very often since the intent is to create manifold pressure, which would seem to be more likely to equalize pressure in the plenum better. On NA and nitrous engines, where I think this is most common, I would expect that you would get a ramming effect in the back of the manifold creating a denser air charge (re: leaner) for that #7 runner.
08-10-2010, 08:40 PM
#46
Back from the dead....... My #7 looked EXACTLY like the OP pic!!! SAME spot EVERYTHING!!! IDENTICAL spot!!! I only have phone pics so I will take some with the camera later and post up. Car threw no codes and ran fine but it may not have run long since this happened...
I just wanna know so the new 403 going in doesn't suffer the same fate...
I just wanna know so the new 403 going in doesn't suffer the same fate...
12-02-2010, 07:29 AM
#47
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back from the dead again.. my # 7 cracked piston looked the same.. on motor too h/c setup. PTV was good and all... valve hit the piston and plug tip was bent!
sucks cheap fix is still $ and u leave with same hp.. so I went the long route... expensive fix but u leave with a **** load of power! hahaha
6 bolt head 427 in the works for me. now if that breaks ill jump a cliff..
sucks cheap fix is still $ and u leave with same hp.. so I went the long route... expensive fix but u leave with a **** load of power! hahaha
6 bolt head 427 in the works for me. now if that breaks ill jump a cliff..
12-02-2010, 07:40 AM
#48
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The chances of a big chunk of metal finding its' way out of the cylinder through the exhaust valve without doing further damage along the way are VERY slim. Conversely, who would put a motor together with a piston that looks like that? Time to call Perry Mason on this one.
12-02-2010, 09:21 AM
#49
Since Zig (demonpixel) is on vacation, I'll go ahead and post an update for him.
The old block was indeed cracked so it was junk. We found a new LS6 block, rebuilt it with a Wiseco/Lunati spec piston, and just before he went left on vacation, he heard it his old 'Bird fire up for the first time in months. Pardon the mess. The next step is to clean it all up and get rid of the rat's nest. BTW, that's EFI on there...
The old block was indeed cracked so it was junk. We found a new LS6 block, rebuilt it with a Wiseco/Lunati spec piston, and just before he went left on vacation, he heard it his old 'Bird fire up for the first time in months. Pardon the mess. The next step is to clean it all up and get rid of the rat's nest. BTW, that's EFI on there...
12-02-2010, 12:59 PM
#52
love the old Formula!
Ya, it sucks when this happens. My H/C car had a similar failure at 38kmi. It knocked/clacked quite noticeably afterward (I doubt the OPs motor ran quietly with that broken ring land). Upon disassembly, there was little evident damage, only a slightly bent spark plug ground electrode, some light colored speckling on the combustion chamber, and a piece missing off the #7 ring land.
I thought maybe the broken piece was fired cleanly out the exhaust port, but once I got the oil pan off and removed the steel baffle, I found a good amount of finely ground aluminum.
I have no idea why it failed. The car was tuned by someone that knows their stuff. I may have gotten some bad gas or had weak fuel pressure.
A million dollars later, I have a nice stroker in it now, and I'll be looking for low tens come Springtime
Ya, it sucks when this happens. My H/C car had a similar failure at 38kmi. It knocked/clacked quite noticeably afterward (I doubt the OPs motor ran quietly with that broken ring land). Upon disassembly, there was little evident damage, only a slightly bent spark plug ground electrode, some light colored speckling on the combustion chamber, and a piece missing off the #7 ring land.
I thought maybe the broken piece was fired cleanly out the exhaust port, but once I got the oil pan off and removed the steel baffle, I found a good amount of finely ground aluminum.
I have no idea why it failed. The car was tuned by someone that knows their stuff. I may have gotten some bad gas or had weak fuel pressure.
A million dollars later, I have a nice stroker in it now, and I'll be looking for low tens come Springtime
12-02-2010, 03:09 PM
#53
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shev...**** happens mine was tuned by Carmen from vette doctors. stock piston ringlands can take so much...well not much. Especially if your hard on the car and enjoy it.
well onto bigger and better things.
well onto bigger and better things.
