nvrplzd240
03-06-2007, 07:56 PM
I recently swapped cams in my 1990 Nissan 240sx to HybridKA's GB4 cam. She runs/drives fine, but around 2200rpm tapping occurs within the head. I originally thought it was the lash adjusters so I took them apart and cleaned them/reassembled them. When they were apart I noticed marks on the bottom of the rocker arms indicating contact with the top of the valve spring. My thinking is the tapping is coming from this contact. It only occurs on the exhaust side. I had the cam towers milled .025 as called for but never double checked the machine shops work before I put everything back together. The machine shop is a pretty reputable place too.. not shady at all. I was just wondering if you guys could shed any light upon my situation.