Oil pressure and Oil viscosity

[RET_COP]

HP= High Prersssure
HV= High Volume

[Gaz64]

Any pump can be made higher pressure, but only at a higher engine speed, by changing the relief spring.

A HP or HV regulated pressure can be set lower or higher for the MAXIMUM pressure.
The HV pump WILL deliver more pressure to the engine progressively up to the regulated pressure because of the larger gear set.
A high volume pump takes more power to turn, so wears distributor and cam gears faster.

10psi per 1000 rpm is still a good rule.

OIl flow though the bearings is more important than oil pressure.

A tight clearance engine with a HV pump and thick oil is a bad example.

[cobra 53]

Gary, Thanks for the explanation.

New oil is 10/40 and the oil pressure gauge still marks between 50-60 psi idling with warm engine. Turning up to higher rpm it marks at 70 psi.
How can I see or check the pressure rate of the installed relief spring? I know there are different spring rates available (Youtube, Melling oil pump Videos).

The HV pump conducts enough oil, so I think it would be possible to go with a lower spring rate.

[cobra 53]

Reply failure.

[Gaz64]

Originally Posted by cobra 53

Gary, Thanks for the explanation.

New oil is 10/40 and the oil pressure gauge still marks between 50-60 psi idling with warm engine. Turning up to higher rpm it marks at 70 psi.
How can I see or check the pressure rate of the installed relief spring? I know there are different spring rates available (Youtube, Melling oil pump Videos).

The HV pump conducts enough oil, so I think it would be possible to go with a lower spring rate.

You might find benefit in going to a thinner oil again, like 5W30.

You then might end up with 30-40psi at idle and still have 70psi as a max, although at a little higher rpms.

I wouldn't bother changing the spring to lower the maximum, it's fine at 70psi.