I posted a topic in the LT1 tech section about an odd oiling problem I'm having. One of the replies was that it could be "oil pump cavitation". I was wondering if any of you could shed some light on this. I'll be doing a heads and cam swap in the summer and I want the oiling system in top shape.

Symptoms- If I'm going along at about 3000 RPM in second gear and go WOT the oil pressure starts out at about 40psi. As the revs increase the oil pressure gets up to about 45 and then all of a sudden drops to 25. This scared the crap out of me the first time I saw it happen so I let out. I thought maybe the oil was a little low. So I changed it and topped the oil off(it wasn't low by the way). I once again tried a second gear pull. This time when the oil pressure dropped I stayed in it. To my surprise a second or two later the oil pressure came back up to 45-50psi

At first I thought that maybe it was the bypass valve in the block opening, but I've been told that's not likely to cause this. Someone suggested that it might be the bearings, but I would think if my bearings were warn the oil pressure wouldn't come back up again. Plus from what I can tell the motor is in great shape. BTW this is a stock motor with 120k miles.

Thanks
John

 

Perhaps the sudden jump to WOT is pushing the oil away from the oil pump pickup.