this is not honda related but an engine is an engine right.
my brother brought his z24 to me today and it has a pinging sound.. sounds like the rockers, starts and stops mostly constant sound gets louder when the engine reves up, not a deep sound, sounds like a small ball peen hammer tapping on the engine. i've done engine overhauls and rebuilds, but never trouble shooting.
no coolant in oil, no oil in coolant, replace plugs, added oil treatments,,
any other ideas, if i need to i'll replace lifters etc...