Ford Windsor 427 SB excessive oil pressure

[bobcowan]

Originally Posted by Davidless

Thanks for all the info

Not sure I understand about reducing the bypass spring force, in that case what’s the sense of using a high volume pump?

David

Do not equate pressure with volume.

[patrickt]

There are times when you want a high volume pump. In contrast to your small block, my stroked flat tappet FE has .003 main clearances and .0028 rod clearances. It also has a remote filter and an oil cooler. It runs 15w40 oil and my hot idle pressure is 15psi, sometimes less. This is when idling at 650 and my oil pressure comes up instantly with revs and generally will be in the mid 40's at 2000 RPM when really hot. The lifter galleries are plugged (solid cam) and I have .060 restrictors up top in the heads. And I run a Melling high volume pump.

[eschaider]

Originally Posted by bobcowan

Do not equate pressure with volume.

Pressure and flow rate (volume) are linked at the hip, although they do not have a first-order relationship. The relationship between pressure and flow is a second-order relationship.

Flow increases as the square of pressure. To double the flow through an orifice, you will need to raise the pressure of the fluid pre-orifice by a factor of four (2 squared).

It is not just simplistic to say they are not related, it is wrong. They are linked at the hip.