RiverJeff
Active Member
- Joined
- Sep 21, 2016
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Ok guys who can help with this one.
Ive got a 572 Big Block Chevy in a jet boat with a weird high rpm oil issue. The engine makes 40psi hot idle, holds a steady 65-70psi up to 4500 rpm but then anything over 4600-5000rpm and the oil pressure immediately drops to ~20psi.
The drop happens right away over 4500 rpm and the pressure shoots back to 65-70psi when you lower rpm back to 4000-4500psi. It does get some air bubbles on the stick after the run but with how fast the pressure comes back I feel like the air is a symptom not the cause.
Anyone know where to look?
Here is the set up:
-Bowtie Chevrolet Block (OEM drainage)
-Merlin Cast Iron Heads (OEM drainage)
-Milodon 10qt pan with full windage tray (I've run 5,7,10qts & same issue)
-Milodon pick up bolted to pump
-Melling HV77 pump - new
-Pink pressure relief spring - 70psi
-Solid lifters with .060" restrictors
-Pressures verified with mechanical gauges
Ive got a 572 Big Block Chevy in a jet boat with a weird high rpm oil issue. The engine makes 40psi hot idle, holds a steady 65-70psi up to 4500 rpm but then anything over 4600-5000rpm and the oil pressure immediately drops to ~20psi.
The drop happens right away over 4500 rpm and the pressure shoots back to 65-70psi when you lower rpm back to 4000-4500psi. It does get some air bubbles on the stick after the run but with how fast the pressure comes back I feel like the air is a symptom not the cause.
Anyone know where to look?
Here is the set up:
-Bowtie Chevrolet Block (OEM drainage)
-Merlin Cast Iron Heads (OEM drainage)
-Milodon 10qt pan with full windage tray (I've run 5,7,10qts & same issue)
-Milodon pick up bolted to pump
-Melling HV77 pump - new
-Pink pressure relief spring - 70psi
-Solid lifters with .060" restrictors
-Pressures verified with mechanical gauges