We've all seen/done/read about this problem - cold start oil press goes off the gauge (100 psi), only 60 warm. Needless to say, 100 does bad things to the drive gear and cam bearings.
Thinking about what to do. Bill Jenkins solved this for Chevy 25 years ago - the max press relief port isn't big enough at 5/16", so he removed the plug and re-drilled the passage leading from the relief valve back to the feed side to 3/8".
Normally the relief port exhausts to the intake, but this isn't really necessary. If accessible, another hole leading to the pump exterior could be drilled to allow more volume to be dumped when the valve is open. The hole could be positioned at the far end of the relief valve travel, so it's only used when the valve is fully open. Excess oil would dump right into the pan. If (for example) the existing port was 3/8" ID, an extra hole 3/16" diameter would add about 23-24% to the volume.
Effect (if sized correctly) that cold press and hot press would be much closer and predictable.
Thoughts? Experiences?
Thanks.
Thinking about what to do. Bill Jenkins solved this for Chevy 25 years ago - the max press relief port isn't big enough at 5/16", so he removed the plug and re-drilled the passage leading from the relief valve back to the feed side to 3/8".
Normally the relief port exhausts to the intake, but this isn't really necessary. If accessible, another hole leading to the pump exterior could be drilled to allow more volume to be dumped when the valve is open. The hole could be positioned at the far end of the relief valve travel, so it's only used when the valve is fully open. Excess oil would dump right into the pan. If (for example) the existing port was 3/8" ID, an extra hole 3/16" diameter would add about 23-24% to the volume.
Effect (if sized correctly) that cold press and hot press would be much closer and predictable.
Thoughts? Experiences?
Thanks.
