one of my posts transferred over from tuners
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I have taken away 10 degrees of timing, knocks just the same at partial throttle, (using the global timing sliders) Added timing, knocks just the same, went from the aggressive 1g timing maps, to the evo timing map... same thing... went to the 2G timing map now. Also I don't hear any audible knocks or pining. Just the knock sensor picking it up.
Base timing is 4-5 degrees. Only this is the cams are just zero'ed out for now... didn't bother degree'ing them as they will be tuned by HP on a dyno eventually. But I had this same knock at partial throttle before even installing the cams. Also has new 3G lifters in it, have tried disconnecting the exhaust, motor mounts are still stock, no solid/poly ones yet
Almost tempted to put knock ignore settings on anything below 50% throttle and 3200 RPM and try and just ignore it.
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Also should add that about 6 months ago #4 piston broke the ring lands partially off the piston. Took engine apart, replaced with used piston/rod. Re-ringed all 4 pistons, honed the cylinder walls, replaced rod/main bearings, checked the balance shaft bearings (looked OK, but never did a inframe rebuild, never removed trans/front cover/oil pump) months after that, #1 piston broke its ring lands almost identical to before. Took engine apart, and again put anot, all bearings that came out and looked in good shape besides slight normal wear for 150,000km motor. Put in another good used piston/rod in, another quick re-hone and all new rings again. Just finished the break in... put about 250 km's on it since then. Don't want to take this damn thing apart again!
I just had the short block apart! changed all the bearings (rods and mains), balance shafts all looked and spun perfect. No issues I could see at all with the bottom end. bore is still within spec, and ring gaps are on the outside of the spec, but still in spec nother the less. After the first piston (#4) had the ring lands crack.. I changed the injectors (were FIC 850's) to 1000cc PTE's because the flow tested slightly out of range. Made no difference, still knocked the exact same. then the second ring lands cracked (#4) and now im just struggling to find the cause, but seems in vein. Very very frustrating. Tonight I am going to run a separate signal wire and shielded ground from the knock sensor to ECU and see if that helps. To note also, its a 91 talon, but it has a 1990 eprom running it with the wires switched. The original ecu was a ecm link converted non eprom... massive amount of knock... swapped in a different ECU, and the knock counts got MUCH better, and way less frequent... but still had knock fits sometimes as well. but no where near as bad with the other ecu. Really weird.
Also the lifters, has topline 3g revised ones installed about 2 years ago... thing still picked up knock then, eventho the lifters never made noise. When I rebuild/redid the engine a couple months ago, I also installed another new set of 3G revised lifters to be sure.... didn't make any difference. also installed upgraded springs/retainers and SS engbldr valves at the same time.
I went to the direct access tables, and did adjust all the sliders for TPS tip in fuel volume way up... re-tested, made no difference in the knock as well. Put the tables back down to stock settings again afterwards.
Heres a pic of the first pison, and the cracked ringlands.