Originally Posted By: Death_Eagle_571
Hey guys, I'm new here, and I just bought a 1966 Ford F100 with the 240ci Straight-6 engine, I'm not sure what oil was in it when I bought it, but it was pretty nasty looking. The oil pressure at 2000-2500RPM was around 55 psi. since then I changed the oil and used Shell Rotella-T 15W-40, it has dropped to around 20-25 psi. the Specification for my engine is 35-55 psi @ 2000RPM I was reading that my truck called for Straight 30W oil, but I was under the assumption 15W-40 would work, and the ZDDP additives in this were sufficient to protect the flat tappets in my engine if I understand it right. Anyway, any ideas guys?
What is the psi at 3,500 RPM?