I needed an engine to race with this year (since I havent complete my pontiac yet) I put together a small block chevy 400 with some used parts I had laying around the garage. Here's the problem, I notice when I had it on the dyno that it oil pressure was fluctuating alot. I just wanted to know if anybody know's what causes this?? It has a standard volume/pressure oil pump. I ran 20w50 Valvoline race oil. The clearances are .003 on the mains and .0025 on the rods. Im attaching a copy of the dyno sheet so you can look at different oil pressures at the different rpm. The only things that I have come up with is that the pump is possibly cavitating or the pressure relief valve in the pump is slaming back and forth. If anyone has an idea please let me know.
Thanks
Jason Dammen
