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In a post of Friday, 8/12/05 6:42 PM (PDT, not EDT), I speculated on whether or not a "rattling" sound that I heard, was detonation. As promised, the update is as follows:
I have driven the car numerous times after I adjusted the ignition shielding, and removed the sidepipe cover plastic protectors. I no longer hear the offending sound, so I must conclude that there was no detonation. Most likely, the shielding was rattling against the clutch bellcrank. To further check, when I mash the throttle in 4th gear at an engine lugging 1500RPM, all is quiet. My centrifugal advance, as measured, is "all in" @ about 2200RPM, so, as another test, nail the gas at 2200RPM and all quiet.
So, I hope that this followup has allayed anybody's fears of building a SHP smallblock using the original type domed pistons. As generally accepted around here, a correctly built SHP smallblock DOES run well on today's 93 octane gas.
Joe
I have driven the car numerous times after I adjusted the ignition shielding, and removed the sidepipe cover plastic protectors. I no longer hear the offending sound, so I must conclude that there was no detonation. Most likely, the shielding was rattling against the clutch bellcrank. To further check, when I mash the throttle in 4th gear at an engine lugging 1500RPM, all is quiet. My centrifugal advance, as measured, is "all in" @ about 2200RPM, so, as another test, nail the gas at 2200RPM and all quiet.
So, I hope that this followup has allayed anybody's fears of building a SHP smallblock using the original type domed pistons. As generally accepted around here, a correctly built SHP smallblock DOES run well on today's 93 octane gas.
Joe