[CYCLONE 1952]

SINCE I HAVE HAVE REBUILT A 364 I HAVE HAD A PROBLEM WITH HIGH OIL PRESSURE (90LB)@3000 RPM THIS CAUSES THE LIFTERS TO PUMP UP TO THE POINT THAT THE VALVES RIDE AND THE ENGINE RUNS ERRATIC AND STALLS .THE MASTER REBUILD KIT WAS SUPPLIED BY KANTER ALL THE MACHINE WAS DONE BY A VERY RECOGNISED AND RESPECTED LOCAL FIRM .I HAVE REMOVED THE OIL PUMP SEVERAL TIMES TO CHECK CLEARANCES AND THE RELIF VALVE . I HAVE TESTED THIS BY MEANS OF REMOVING THE BALL AND SPRING I PULLED A PIECE IF AIR HOSE THROUGH FROM THE BALL SIDE AND UP OUT THE PUMP BODY ON THE PRESSURE SIDE REFITTED THE BALL AND SPRING AND CAP I PUT A PRESSURE GUAGE IN LINE AND INTRODUCED AIR AT 40 PSI THE VALVE STARTED TO FLUTTER INCREASED THE PRESSURE TO 50 PSI AND THE VALVE FULLY OPENED,NOW THE THING THAT CONSERNS ME IS THE GENUINE BUICK CHASIS MANUAL STATES THAT THE RELIF VALVE IS SUPPOSED TO MANTAIN THE OIL PRESSURE TO A CONSTANT 40PSI
HOPE SOME ONE HAS GOT SOME IDEAS REGARDS TONY IN OZ

[Smartin]

What weight oil are you using?

[CYCLONE 1952]

PENRITE 15 W 40

[Bhigdog]

It seems to me that if the bypass valve is doing it's job then the pressure cannot exceed the set pressure (40#). There is nothing else in the engine that could boost the pressure over the set limit.
The valve may be cracking at the set PRESSURE in your test but are you sure it is free to open up enough to bypass the required RATE of flow. Is it possible the spring or ball is hanging up just past the cracked position?......Bob

[Smartin]

I don't ever recall seeing lifters pumped up past their capacity. Did you have the deck of the block and/or heads milled more than a few thou? If so, your pushrods could be too long.

[CYCLONE 1952]

I CHECKED THE HEIGHT TODAY AS YOU SUGGESTED WITH A VALVE FULLY CLOSED I CAN SLIGHTLY LIFT THE ROCKER ARM OFF THE VALVE STEM I TRIED THIS ON ALL THE VALVES INTAKE AND EXHAUST ON THE RIGHT HAND SIDE.
THE HEADS WERE JUST LIGHTLY SURFACED THE REPLACEMENT GASKETS WERE A COMPOSITE TYPE VERSES THE ORIGONAL WHICH WERE A THIN METAL TYPE SO THIS WOULD RAISE THE HEAD A LITTLE.
I INTEND TO SET THE OIL PUMP UP IN AN OLD OIL PAN AT THE SAME HEIGHT AND SPIN IT AT APPROX 2000 RPM AND I HAVE SET A TAP/VALVE & A GUAGE ON THE OUTLET SO I CAN RESTRICT THE FLOW AND MONITOR THE PRESSURE REGULATOR I'LL KEEP YOU POSTED WITH THE RESULT THANKS TO ALL FOR YOUR INPUT

[CYCLONE 1952]

PROBLEM SOLVED AS PER MY SUBMISSION ON THE POST WAR FORUM

THANKS TO ALL HOPE TO HAVE INPUT IF I CAN ASSIST IN THE
FUTURE REGARDS TONY I WILL TRY TO POST PHOTOS