341am

Ok so I have a d16z6 block, cp pistons, eagle rods. As for the head it is a d16y8 with supertech valve train, and crower stage 2 Cam. I recently put the motor in and did the initial start up. Everything was fine no leaks, no knocking, everything seemed smooth. I retorqued the arp head studs, and changed the oil after the first heat cycle. I went for the initial test drive, everything seemed fine. Oil pressure was good...80-85 psi on start up and 15-20 psi once warm. The afr's seemed fine... In between 14 ish at idle and between 11-12 on throttle. Drove roughly a mile and headed home. Once I pulled into the house, there was a noticeable pinging/ knocking. I immediately shut down. I did another oil change and the oil was fine, a little metallic but nothing out of the ordinary for a fresh motor. The magnetic drain plug didn't really have anything on it. I then checked the valve lash which was within normal service specs. I also rechecked the head studs, and everything was fine. No smoke or oil in the catch can. No smoke from the car. I took a few extensions and listened to the motor and it seemed to be coming from the back of the head almost resonating the intake manifold. The car is on a base map on crome with 560 cc injectors.
Does anyone possibly know what i might be dealing with. looked through the spark plug holes and didn't see anything to make me believe that the piston and valves collided. The car also idles without a hiccup.
I'm stumped any info will be greatly appreciated. Thank you all..

Fabrik8

I would imagine it has to do with the basemap you're using, or maybe something with piston clearance. Some types of piston alloys are noisier than others, but usually that doesn't change very much with engine temperature. So I'm going with the basemap theory. So you probably need an actual tune. How are you monitoring A/F ratio? Do you have a wideband?

341am

I'm monitoring the air fuels via Aem Wideband... The base map is my old tune from the previous setup, which was identical with the exception of vitaras and fj rods... Also the ignition timing was set to factory via timing light, and my cam gear is set to 0.

341am

The car also went through about 4 heat cycles throughout a week prior to the first oil change.... No driving just heat cycles.