Oil Pump Performance

When changing from a stock oil pump to a high volume ( not high pressure ) pump , - what would be the expected increase in oil pressure? {if any}


Currently at idle speed after reaching full engine temp, I am seeing 15psi with the stock pump - I would like to see at minimum 30 - 35psi but am hoping for around 45+
Is this a realistic expectation??

I am considering the change because i suspect less than optimal performance due to excessive wear in the pump spline gears

It isn't pump wear that makes the pressure low, it is wear at the main bearings (sxcessive clearance). Going to a HV pump is only a bandaid fix for a bigger problem. If your oil gauge is reading right and you have only 15psi at idle, it may be time to start thinking about replacing the engine...What is your oil pressure at 60 mph (2k RPM)?

at 60mph the pressure reads 45+ with the stock pump

I had the mechanic gauge the tolerances on the mains just to be sure and he said they were fine and showed no signs of scoring and no heat damage.
The inside of the engine was very clean -no sludge or build up and he also said that everything was getting sufficient lubrication

So my theory about the oil pump wear was on target

Those pumps don't wear out (unless it was run without oil), the pressure spring in it may be bad (long shot) or there may be trash in the pump or blocking the screen

The pump was never run without oil
The mechanic said there was no blockage or trash

The pressure spring may be the cause

but anyway, it is replaced now and he should be nearing completion of the reassembly shortly and then i can see what the performance difference (if any) between the 2 pumps is

One thing you may see from the HV pump is oil starvation during hard acceleration in a corner. The better pump to get would have been a Melling standard volume pump and have a high pressure spring installed.
But done is done. Hope the new pump solves your oiling problem