540 Hemi in a mostly street car that sees occasional 7,000RPM passes at the local 1/8th.

My hot oil pressure is high 20s at idle (900+/-) and maxes in the high 60s just after 3,000RPM. That is more pressure than I need, isn't it? Are most of you comfortable with 10+PSI at idle and 60PSI max?

I have been running VR-1 20/50 for years now with no issues. But VR-1 is only available in 20/50 and 10/30.

I am thinking about trying the 10/30 VR-1, but just want to make sure that I am not taking any undue risk doing it.

I would appreciate your thoughts and opinions on this.

how many miles on the motor?

1,200 miles +/-

No noise then quit worrying about it the engine is fine

I was told you want to use 20-50 in the hemi's because the thicker oil will stay up in the top of the head longer to lubricate the intake rockers. I think the oil pressure you have is perfect.

The old 10lbs. per 1,000 rpm thing. Yours sounds about right. I wouldn't go with the 10w-30 though. The pressure will go down, especially at idle. Just make sure it's full and depending on the gauge, I think you are fine. The reason I mention the gauge is because a 100lb. gauge might read different from say a 150lb. gauge or a Racepak pressure sensor.

Do you often start a REALLY cold motor (you are in Illinios)? Cold as in below say 35-40?

If so I would be very leary of 20w50. Your oil pressure numbers look like they will support 10w30 just fine. Try it.

An interesting test: pour some oil into a jar, put in freezer overnight. Then see how they pour.
I was amazed, years ago, at how thick Castrol GTX 20w50 was!

It's only going from 10w to 20w. There is a difference but it's not like going from a 10w to a straight 40w. When I change the 15w-40 in my diesel it comes out like water. IMHO I would run synthetic oil in that beast.

Valid points on the cold weather thing. I don't start it below maybe 50* or so. And I have an Accusump that I prime with to help.

So far, it's about even between 'leave it alone' vs 'try the 10/30'.

I've heard two conflicting rumors about Hemi oiling; one is that you want a heavier oil to cushion between the crank and the heavy recip assembly. Although mine is lighter than stock being Barton pieces. The second is that a lighter weight oil flows more, particularly over the valve springs, thereby cooling them better.

I don't have any issue leaving well enough alone (meaning staying with the 20/50) if that is what is best for this engine. But if there were any real advantages to going a lighter weight, then I would certainly do that.

If there were a 15/40 VR-1, I would be comfortable trying that as it's not as drastic a step as going to 10/30.

Here's another question; the oil pressure tops at about 68lbs just past 3,000RPM. So doesn't that mean that any volume after that is just bypassed back to the pan?

Wouldn't a lighter weight oil that doesn't by-pass until higher PRM be flowing more?

Try it and let us know what you find out! You certainly won't hurt anything. This is a street car with an occasional wide open blast right? The Accusump is great! Oil pressure before the engine turns a lick! Also extra capacity which is always good.

What are your bearing clearances?

What does Barton recommend?

How hot do you get this engine on the street? Do you hot lap it at the track?

Your pressure does not seem too high like some with 80 psi.

I don't go along with the thick oil group.

Me too!

10/30 Mobil 1. We use it in everything incuding SS Hemis

For reference, I used to run 20-50 in myb383. Took forever for the pressure to come down enough that I felt comfortable driving.

Dropped to 10-30, better warm up, no difference in pressure.

Dropped to 5-30, Even better warm up and still no drop in hot pressure.

I've considered trying 0-20. It's just an oil change and if it doesn't work drain and refill.

I have a high volume pump and deep Moroso pan but only run 6 qts.

I ran 5W20 WT standard non synthetic Valvoline that Wal Mart stocked in my old pump gas Duster, it would have right at 18 to 20 lbs at 850 RPM in gear with 180+ F oil temps., 30+ lbs at 1200 RPM and 65 lbs. above 3000 RPM with the same oil temps. That motor made 727 HP and 700 + Ft lbs. on pump Oregon 91 octane pump gas the last time I had it on a DTS engine dyno with that oil and oil temps. I would shift the motor at or a little above 7000 RPM with 65 lbs. pressure, no problems with the bearings or any other parts in that motor, solid roller cam with full time oiling to the Harland Sharp roller rockers with a .040 restrictor to each side 250 Lbs. pressure on the seats and 650 lbs. open pressures
Lots of myths on oil and every other part found in our Hi Po motors, not every one agrees on any of them

I'd be happy with those numbers and I would stay with the 20/50 mineral , what could possibly be achieved buy going to a thinner oil.
I always get heat into my engines before they get a beating.

I would for sure try the thinner oil. I'd want the thinnest oil that maintains the psi I am OK with. I may be off base on this & I do not know Hemis but I don't think using a heavier oil cuz it stays up top later is valid, I'd want the thin oil continually flowing. Nascar goes with thinner oil for a reason.

I switch from straight 30wt oil to 5W20Wt oil do to seeing right at 8HP gain running the oil temps on the engine dyno testing from 130 F to 160 F I then tried 10W30WT and saw 3 HP difference going from 130 F to 170 F.
The next engine I tested was with 5W20WT and I saw no differences in HP going from 80F to 200 F oil temps on a roller cam bracket race motor
Oil does two things in our motors, it lubricates and cools the parts it touches The sooner it is lubricating it is also cooling resulting in less wear and tear on our parts

I would try the thinner oil and see what your hot idle pressure looks like after. I think you'll be ok.