have a 512 stroker with adjustable oil pump and the current pressure setting I have has got 90 psi at start up and idles at 30 when hot and runs from 40's to 60;s when giving it rpms
My question is do you think 90 is in danger of blowing seals. I can turn it down to 70 at start up but then idles at 20 when hot and is that kind of low ?

I'd be wondering why the bypass is letting it get to 90 myself.

20 at hot idle is plenty, I also wonder about the bypass

This is another example of not keeping it simple. A stock/hv pump out of the box would have given the required 70/20 psi without hassle. Just my opinion

Probably the bypass pressure goes up with running pressure. Might give more info on the pump.

so since i can adjust it to the required 70/20 I should be fine,I guess I just have the setting to high at 90/30 ? is 90 to high ?
Melling m63hv pump with milodon adjustable oil pressure valve
VR1 20 50 oil tried there 10 30 but was going down to 15 at hot idle but immediately went into 40's with rpm's and had like 70 at cold start up but was thinking 15 might be to low

What are your bearing clearances and what viscosity oil is being used?

Two considerations to know what you need.

Joe

Only reason the bypass pressure would go up is of the oil pump is pumping so much oil that the bypass cannot dump the excess.

90 psi cold is too much, 70 psi warm is too much, imo. I like to see no more than 60 psi warm cruising.

15 psi at hot idle is fine.

20w50 is way too thick. I like to use just enough oil viscosity to get the pressure I want, any more is wasting HP. Typically I run 5w30. Which also cuts down on cold oil pressure.

5w30 or 10w30 would probably be better shooting for 15lb or so hot idle and 60lb or so hot cruise.

I have a 440 source adjustable set up on my M63HV pump, the 63hv comes with a high pressure spring, I had to cut one coil off the spring to make the adjuster & pressure work correct.

I have the same problem with my hemi. Stock Melling M63HV 10-30 mobile 1. 80psi cold idle 55 hot idle goes right up to 75 @ 2,000 hot? Can get over 90 hot at rpm's. Silver spring. I put on a M63H and it doesn't get over 45 psi hot pink spring. Would be happy at 65 max hot. I thought about changing springs but wouldn't the pink spring bypass at 45 even in the HV pump. Also thought about shimming regular pump spring but unsure how thick shim would have to be to increase pressure 20 psi. Suggestion's?

i like to see around 70-75 cold start, 20-25 hot idle, and 60[ish] at cruise.
however, 10-15 at hot idle of 800-1000rpm works if it jumps to 40[ish] at a tickle of the gas pedal.
i prefer a tad big bearing clearance and 10-40 or 15-40 oil.
just my opinion. your mileage will vary.

I have the same problem with my hemi. Stock Melling M63HV 10-30 mobile 1. 80psi cold idle 55 hot idle goes right up to 75 @ 2,000 hot? Can get over 90 hot at rpm's. Silver spring. I put on a M63H and it doesn't get over 45 psi hot pink spring. Would be happy at 65 max hot. I thought about changing springs but wouldn't the pink spring bypass at 45 even in the HV pump. Also thought about shimming regular pump spring but unsure how thick shim would have to be to increase pressure 20 psi. Suggestion's? [/quote]

Start with a .020 or .030 shim & try it pink spring. will probably need a little more, but that is a good starting point, or cut one coil off the HP spring

Are the rotors different thicknesses between the HV and non HV?
I’m assuming they are but don’t want to assume.

Same design in both?

yes

The HV is thicker, more rotor

just leave it as-is... pressure cold in meaningless and what seals will it blow out?... only need for messing with it is if you need every last 1/10 of a hp out of it... enjoy it

I shoot for 10 lbs. per 1000 RPM with hot oil, 160F +
I like and use thin oil, 5W20Wt so I have oil pressure as soon as the motor starts, my old pump gas 511 and later added .050 stroke to raise the compression ratio from 9.25 to 1 with iron 906 heads to 10.29 to 1 with aluminum Eddy RPM heads, that motor made 700 HP on pump swill and had between 18 to 20 lbs. oil pressure idling at 850 RPM in gear, it would have 30 lbs. at 1100 RPM and 65 lbs. at or above 6000 RPM with 180 F oil temps I beat the snot out of those parts and they lived forever
Oil does two things for us, it cools and lubricates
Do you know if your oil pressure gauges is dead on or can it be reading a little high or low
AKA, your good with what you have now

Roger dodger ... to our old from Bendover

Toooo much oil pressure is actually worseEST ....

... than using tooooo many smilies in a single post

I wounder why the idle pressure went from 30 down to 20.