" GRUMPY?? WHAT CAUSED THIS< IVE GOT 4 pistons with busted rings,
I pulled the engine down to see why I had low compression, Did my removing the EGR do this? (high cylinder temps?) I plan to put a new one on when I get it back together. I also run premium 93 octane in this thing, and run it at 8 BTDC. Timing light shows the timing bang on, and I've never heard a ping or knock from the motor before. Only thing is the motor is noisy, especially idling.
Either way, I'm in no hurry to get it back together, just want it done right."
, the most frequent cause of busted rings is DETONATION or improper installation, (wrong ring end gap, rings wrong size etc.) look closely at the ring ends there might be indications they were binding in the bore, and check the piston grooves , for damage.
or failure to tune the car correctly, (wrong fuel air ratio, faulty ignition advance, TDC not correct on timing tabs or damper etc.)
theres obviously a good deal of varnish or burnt oil residue on those pistons, so careful cleaning in a good solvent and use of a ring groove tool and careful detailed inspection and measuring clearances is highly recommended before thinking about re-use of those pistons
you can,t always hear detonation, Id say, some time spent CAREFULLY reading the linked (and sub linked) info in these threads is sure to help,
and I would verify the TDC marks on the timing tab and damper are correct its sure not all that rare to find they are not correctly indexed to CORRECTLY INDICATE TRUE TDC
damage to the ring lands can be caused by detonation or just the ring gaps set to tightly
detonation from crappy octane fuel or the wrong ignition advance curve way out of adjustment can beat pistons to death
why cast cranks and high stress and rpm are a bad idea
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I pulled the engine down to see why I had low compression, Did my removing the EGR do this? (high cylinder temps?) I plan to put a new one on when I get it back together. I also run premium 93 octane in this thing, and run it at 8 BTDC. Timing light shows the timing bang on, and I've never heard a ping or knock from the motor before. Only thing is the motor is noisy, especially idling.
Either way, I'm in no hurry to get it back together, just want it done right."
, the most frequent cause of busted rings is DETONATION or improper installation, (wrong ring end gap, rings wrong size etc.) look closely at the ring ends there might be indications they were binding in the bore, and check the piston grooves , for damage.
or failure to tune the car correctly, (wrong fuel air ratio, faulty ignition advance, TDC not correct on timing tabs or damper etc.)
theres obviously a good deal of varnish or burnt oil residue on those pistons, so careful cleaning in a good solvent and use of a ring groove tool and careful detailed inspection and measuring clearances is highly recommended before thinking about re-use of those pistons
you can,t always hear detonation, Id say, some time spent CAREFULLY reading the linked (and sub linked) info in these threads is sure to help,
and I would verify the TDC marks on the timing tab and damper are correct its sure not all that rare to find they are not correctly indexed to CORRECTLY INDICATE TRUE TDC
damage to the ring lands can be caused by detonation or just the ring gaps set to tightly
detonation from crappy octane fuel or the wrong ignition advance curve way out of adjustment can beat pistons to death
why cast cranks and high stress and rpm are a bad idea
RELATED THREADS YOU SHOULD READ
viewtopic.php?f=55&t=109
viewtopic.php?f=53&t=509
viewtopic.php?f=53&t=852
viewtopic.php?f=53&t=247
viewtopic.php?f=53&t=5454
viewtopic.php?f=50&t=609&p=26934&hilit=detonation+damage#p26934
viewtopic.php?f=44&t=331&p=405&hilit=detonation+damage#p405
viewtopic.php?f=44&t=937&p=1922&hilit=detonation+damage#p1922
viewtopic.php?f=53&t=2837&p=7989&hilit=detonation+damage#p7989
viewtopic.php?f=50&t=8745
viewtopic.php?f=53&t=4630
viewtopic.php?f=52&t=966
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