An upper limit guard is set for {HEAD ~ a valve overlap amount} according to {TAIL ~ a KCS learning value} used to retard correct an ignition timing in order to suppress knock, and an engine load 
according to
An upper limit guard is set for { HEAD ~ a valve overlap amount } according to { TAIL ~ a KCS learning value } used to retard correct an ignition timing in order to suppress knock , and an engine load
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH