I have a L28 in a 260z. The motor has been bored, ported and there is a street/racing cam in it. I have an exhaust header(and larger exhaust pipe) and three 40mm dellorto side drafts. Finally , my question. It runs pretty good until it reaches its full temp wich is 3/4 on the temp gauge(a little less). At this point it drops in power and acts like it is vapor locking. I taped up the header to trap the heat, and it helped, but still runs too hot. My cooling system is stock. What do you think is going on?
Thanks,
Jim [/b]